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Currently, a significant increase in the interest of the triangle grid stiffened plates and panels can be observed. Isogrid, which is equilateral triangle grid concept, was developed in 1964 by NASA as extremely efficient light-weight structures used in space program. Recently, development of machine tools, made it possible to reduce the costs of manufacturing and allowed for wider application of such structures. Paper presents preliminary experimental and numerical investigations of square isosceles triangle grid stiffened plate under pure shear loading condition. Different ways of FEM modeling of plate were considered and analyzed for simple load cases. Critical and post-critical states of deformation were compared to results of experiment conducted with use of 3D DIC system.Currently, a significant increase in the interest of the triangle grid stiffened plates and panels can be observed. Isogrid, which is equilateral triangle grid concept, was developed in 1964 by NASA as extremely efficient light-weight structures used in space program. Recently, development of machine tools, made it possible to reduce the costs of manufacturing and allowed for wider application of such structures. Paper presents preliminary experimental and numerical investigations of square isosceles triangle grid stiffened plate under pure shear loading condition. Different ways of FEM modeling of plate were considered and analyzed for simple load cases. Critical and post-critical states of deformation were compared to results of experiment conducted with use of 3D DIC system.

This paper describes the design and analytical study of tubular linear electromagnetic pulsing motor (EMPM) model with the high response characteristic to suit the electric vehicle (EV) application. The new tubular linear EMPM model based on the working principle of the reciprocating motion, which can eliminate problems related to internal combustion engines such as engine weight and friction where fewer components are used. In this paper, the tubular linear EMPM model has established a mathematical model by equivalent magnetic circuits and permeance analysis methods, which it the same technique as the electric circuit. Furthermore, the magnetic force of the coil and plunger rod was calculated; the design of the electromagnetic tubular linear EMPM is focused on engineering finite element analysis 3D Maxwell software. Finally, the simulation result of tubular linear EMPM are measured the plunger force is ∼37.2KN, thrust is ∼60Nm, plunger distance is 75mm, motor speed is ∼7500RPM and power motor is ∼12.3KW. at current supply 200A. Thus, the graph result shows the comparison between a theoretical and finite element of analysis tubular linear EMPM.

This paper concentrates on selected aspects of numerical modeling of a short span thin-walled beams. The performed numerical simulations cover different types of finite elements (shell or solid finite elements) and different mesh sizes. Moreover the shape and magnitude of an initial geometrical imperfection is also investigated. The numerical analysis were made with the Newton-Raphson procedure with geometrical and material nonlinearity. The numerical results were compared with the laboratory four point bending test of a thin-walled beam. Furthermore, some guidelines for numerical simulations of a short span thin-walled beams in bending were proposed by authors.This paper concentrates on selected aspects of numerical modeling of a short span thin-walled beams. The performed numerical simulations cover different types of finite elements (shell or solid finite elements) and different mesh sizes. Moreover the shape and magnitude of an initial geometrical imperfection is also investigated. The numerical analysis were made with the Newton-Raphson procedure with geometrical and material nonlinearity. The numerical results were compared with the laboratory four point bending test of a thin-walled beam. Furthermore, some guidelines for numerical simulations of a short span thin-walled beams in bending were proposed by authors.

This paper presents a numerical study of a road barrier subjected to a bus crash test. The authors focus on the proper description of a barrier material model. Material model parameters are verified according to a simulated forming process. The solution uses modeling and simulation methods, as well as the finite elements method implemented with LS-DYNA software. The obtained results show that defining a proper road barrier model must consider the manufacturing process. Intensive plastic deformation leads to a significant increase in yield stress only in areas where the highest strain is observed during the forming process. The barrier model is divided into three zones, each of which have material properties characterized by different constants. The described construction, which uses homogenous material, is much more deformed and flatter than that of the improved model. Comparison with the experimental results shows that the new model better describes barrier deformation. In addition, deformation of the barrier under impact is evaluated according to European regulations (EN 1317). In comparison to the performed bus crash test, the crash test parameters obtained in the numerical simulation (static working width and normalized working width) gave more accurate results when the improved material model was utilized.This paper presents a numerical study of a road barrier subjected to a bus crash test. The authors focus on the proper description of a barrier material model. Material model parameters are verified according to a simulated forming process. The solution uses modeling and simulation methods, as well as the finite elements method implemented with LS-DYNA software. The obtained results show that defining a proper road barrier model must consider the manufacturing process. Intensive plastic deformation leads to a significant increase in yield stress only in areas where the highest strain is observed during the forming process. The barrier model is divided into three zones, each of which have material properties characterized by different constants. The described construction, which uses homogenous material, is much more deformed and flatter than that of the improved model. Comparison with the experimental results shows that the new model better describes barrier deformation. In addition, deformation of the ba...

Acquiring efficient, economic and accurate methods for identifying the material properties of heterogeneous materials have been one of themajor objectives in the mechanical engineering community, thus, inverse methods may be considered as contributing to a very promising way of achieving the objective. This paper is concerned with an inverse method for identifying the material properties of a kenaf reinforced compositetest model. Aninitial finite element model of the composite test model is developed and normal modes analysis is carried out to calculate the modal parameters of the initial finite element model. The inverse method which is developed fromMSC Nastran SOL200 is used to update iteratively the material properties of the initial finite element model based on the comparison between the calculated modal parameters and those observed experimentally from experimental modal analysis (EMA). The objective is to acquire the most appropriate set of material properties that provide well match between the finite element model and the test model. It was found that the identified material properties are well matched with that of previous published papers in terms of the reduction in total errors, which are discussed in this paper.

In any engineering analysis or investigation, a complex system is first visualized as a physical model. Then the mathematical model of the same is developed, and then the further analysis is carried out. By this we get good knowledge of the behavior of the system at lesser costs. This paper presents a similar technique adopted for the study of vibration characteristics of SMA Hybrid Composite Beam (SHCB) with one end fixed. Free vibration study is undertaken on a SHCB which is constructed by reinforcing SMA wires in a matrix of epoxy resin along with glass fibers. Homogenization for the determination of effective properties of the composite is carried out based on rule of mixtures. Analytical calculations are done to estimate the static deflections and free vibration frequencies of the SHCB. Static FEA and free vibration analysis are conducted using ANSYS workbench. FEA results are substantiated with the theoretical values.In any engineering analysis or investigation, a complex system is first visualized as a physical model. Then the mathematical model of the same is developed, and then the further analysis is carried out. By this we get good knowledge of the behavior of the system at lesser costs. This paper presents a similar technique adopted for the study of vibration characteristics of SMA Hybrid Composite Beam (SHCB) with one end fixed. Free vibration study is undertaken on a SHCB which is constructed by reinforcing SMA wires in a matrix of epoxy resin along with glass fibers. Homogenization for the determination of effective properties of the composite is carried out based on rule of mixtures. Analytical calculations are done to estimate the static deflections and free vibration frequencies of the SHCB. Static FEA and free vibration analysis are conducted using ANSYS workbench. FEA results are substantiated with the theoretical values.

The paper aims to numerically reflect mineral-asphalt mixture structure by a standard FEM software. Laboratory test results are presented due to bending tests of circular notched elements. The result scatter is relatively high. An attempt was made to form a random aggregate distribution in order to obtain various results corresponding to laboratory tests. The material structure calibration, its homogenization and finite element dimensioning are the issues decisive for the objective mixture description. The representative volume element (RVE) is investigated here, while it does not precisely reflect the material structure it displays relevant global material parameters. The simulation procedure applied here makes it possible to introduce the name of Monte Carlo simulation-based constitutive model.The paper aims to numerically reflect mineral-asphalt mixture structure by a standard FEM software. Laboratory test results are presented due to bending tests of circular notched elements. The result scatter is relatively high. An attempt was made to form a random aggregate distribution in order to obtain various results corresponding to laboratory tests. The material structure calibration, its homogenization and finite element dimensioning are the issues decisive for the objective mixture description. The representative volume element (RVE) is investigated here, while it does not precisely reflect the material structure it displays relevant global material parameters. The simulation procedure applied here makes it possible to introduce the name of Monte Carlo simulation-based constitutive model.

This paper will use ADAMS software, the robot arm portion of annular parking apparatus statics, kinematics and dynamics analysis. The mechanical part of the robot arm is typically four planar mechanisms that is not only simple, efficient, and also provides effective solutions for the effective horizontal dynamic engine lift and parking manipulator internet. In this thesis research to the problem before using vector graphic method of graphically analysts equation, then the use of ADAMS modeling, simulation, calculation. The dynamic modeling of elastic linkage mechanism is carried out by finite element method. In the process of modeling, the instantaneous structure assumption is discarded and the kinetic energy corresponding to the moment of inertia of component’s distributed mass is not considered. In the strain energy, the effect of shear deformation and the effect of transverse displacement on the strain energy are ignored. Therefore, the model established in this paper is only a simple reflection of the characteristics of the system.

The spile-soil interaction has a great influence on the seismic response of bridges. In this paper, a three-span continuous box girder bridge with corrugated steel webs is taken as an example. The finite element model of a continuous girder bridge with corrugated steel webs has been established by Midas Civil considering spile-soil interaction. The influence of spile-soil interaction on the seismic response of corrugated steel web continuous girder bridges has been analyzed and summarized by comparing the seismic response of structures with spile-soil interactions and that without considering spile-soil interactions, providing reference for seismic design of similar bridge types.The spile-soil interaction has a great influence on the seismic response of bridges. In this paper, a three-span continuous box girder bridge with corrugated steel webs is taken as an example. The finite element model of a continuous girder bridge with corrugated steel webs has been established by Midas Civil considering spile-soil interaction. The influence of spile-soil interaction on the seismic response of corrugated steel web continuous girder bridges has been analyzed and summarized by comparing the seismic response of structures with spile-soil interactions and that without considering spile-soil interactions, providing reference for seismic design of similar bridge types.

Since the real structure is not perfect, the geometric imperfections are present. In this case, the bifurcation buckling load overestimates the buckling load. This problem is particularly interesting in experimental studies, because the amplitude of imperfection and its mode can differ for each sample. In this paper, a methodology for determination of the lowest buckling load of a thin-walled plate structure with imperfection using a load–axial shortening plot was presented. The proposed approach can be applied, when the post-buckling path is stable, only. It was shown that the load corresponding to an alternation in rigidity of the real structure on the load-axial shortening plot determines the buckling load with high accuracy. The P-w2 method and the inflection point method were applied, as well, to verify the obtained results. First, numerical calculations were performed by the finite element method and Koiter's method using Byskov-Hutchinson's formulation. The imperfections were defined explicitly. Other parameters of the system, such as boundary conditions, loads, geometrical dimensions were free from inaccuracies. A plate model of the thin-walled structure was applied. An eigenvalue buckling problem of perfect structures was solved to determine bifurcation loads and their eigenmodes. Then nonlinear problem of buckling was solved by Koiter's perturbation method for one mode approach or the finite element method employing Newton-Rawson's method. The load - axial shortening plots were made to analyse an influence of the imperfection amplitude on an approximate value of the lowest buckling load. The uncoupled local buckling was considered. Detailed computations were conducted for short Z-column made of general carbon-epoxy laminate under uniform compression. The Z-column was simply supported on both ends. Finally, the numerical results were verified in experimental tests using Aramis system. A static compression test was performed on a universal testing machine. Tests were performed at a constant velocity of the cross-bar equal to 2 mm/min. The compressive load was less than 150% of the bifurcation load. A very good agreement between the results attained with both the methods for solving the nonlinear problem was obtained.Since the real structure is not perfect, the geometric imperfections are present. In this case, the bifurcation buckling load overestimates the buckling load. This problem is particularly interesting in experimental studies, because the amplitude of imperfection and its mode can differ for each sample. In this paper, a methodology for determination of the lowest buckling load of a thin-walled plate structure with imperfection using a load–axial shortening plot was presented. The proposed approach can be applied, when the post-buckling path is stable, only. It was shown that the load corresponding to an alternation in rigidity of the real structure on the load-axial shortening plot determines the buckling load with high accuracy. The P-w2 method and the inflection point method were applied, as well, to verify the obtained results. First, numerical calculations were performed by the finite element method and Koiter's method using Byskov-Hutchinson's formulation. The imperfections were defined explicitly. Ot...

As a part of the Argonne Strategic Partnership Project (SPP) 85E77, collaboration between Argonne National Laboratory (ANL) and Shanghai Institute of Applied Physics (SINAP), has produced designs for a precision compact flexure bending mechanism to provide elliptically shaped 90-mm and 160-mm long hard x-ray mirrors. The design utilizes Argonne’s laminar nanopositioning flexure technique. The flexure mirror bending mechanism will be incorporated into the beamline upgrade project at the Shanghai Synchrotron Radiation Facility (SSRF). Additionally, an Argonne Laboratory-Directed Research and Development (LDRD) project at the Advanced Photon Source (APS) has adopted a modified optomechanical design of the precision compact mirror benders for 300-mm-long hard x-ray mirrors with integrated profile monitoring and feedback, which are described in this paper. The mirror benders are designed with configurations for open-loop or closed-loop controls. Capacitive sensors can be applied to the mirror benders to ensure positioning reproducibility. Design specifications as well as finite element analyses results of the compact mirror benders for hard x-ray mirrors with trapezoid and rectangular shapes are discussed in this paper.

The stent implants nowadays are wide used technique in the treatment of the cardiovascular diseases due to their long-term life cycle. This life time depends on the type of the deployment, material properties, loading conditions, design and patient anatomy. Present paper presents a study of the fatigue of a new stent design. The geometry is proposed by the firma ISMA EOOD, Sofia, Bulgaria. Stents from medical stainless steel Grade 316L have been exerted to simulation of their fatigue by using Finite Element Method (FEM). Comparison between stents with different struts width is performed. In this work we pursue the aim to reveal the mechanical properties and fatique behavior of a stent with a new original design, using time dependant study. The stress conditions during crimping and inflation of the stent are simulated to obtain the parameters of the virtually implanted graft. Additionally, new conditions are introduced, which imitate the influence of the heart pulse wave. An attempt to predict the failure time has been undertaken taking into account the geometrical design and loading conditions. Goodman analysis has been performed and Safety factor estimated.The stent implants nowadays are wide used technique in the treatment of the cardiovascular diseases due to their long-term life cycle. This life time depends on the type of the deployment, material properties, loading conditions, design and patient anatomy. Present paper presents a study of the fatigue of a new stent design. The geometry is proposed by the firma ISMA EOOD, Sofia, Bulgaria. Stents from medical stainless steel Grade 316L have been exerted to simulation of their fatigue by using Finite Element Method (FEM). Comparison between stents with different struts width is performed. In this work we pursue the aim to reveal the mechanical properties and fatique behavior of a stent with a new original design, using time dependant study. The stress conditions during crimping and inflation of the stent are simulated to obtain the parameters of the virtually implanted graft. Additionally, new conditions are introduced, which imitate the influence of the heart pulse wave. An attempt to predict the failure ...

The paper presents the results of computer modelling using FEA and experimental researches of the influence of technological parameters of burnishing rolling process on resistance to fatigue wear of shafts. For solution of elaborate equation of motion the explicit method was used. This allows to carries out the time analysis of the displacements, strains and stresses state’s in workpieces. In addition, the numerical analyses for the fatigue wear component after burnishing for low frequency loads were carried out. The results of the numerical analysis were experimentally verified by researching the surface layer after burnishing. In addition the shafts on fatigue wear were tested.The paper presents the results of computer modelling using FEA and experimental researches of the influence of technological parameters of burnishing rolling process on resistance to fatigue wear of shafts. For solution of elaborate equation of motion the explicit method was used. This allows to carries out the time analysis of the displacements, strains and stresses state’s in workpieces. In addition, the numerical analyses for the fatigue wear component after burnishing for low frequency loads were carried out. The results of the numerical analysis were experimentally verified by researching the surface layer after burnishing. In addition the shafts on fatigue wear were tested.

The chloride-induced corrosion of reinforcement used to be represented by Tuutti’s model with initiation and propagation phases. During the initiation phase chlorides penetrate the concrete cover and accumulate around reinforcement bars. The chloride concentration in concrete increases until it reaches a chloride threshold value, causing deterioration of the passive layer of reinforcement. Then the propagation phase begins. During the propagation phase steel has no natural anti-corrosion protection, a corrosion current flows and this induces the production of rust. A growing volume of corrosion products generates stresses in concrete, which leads to cracking, splitting, delamination and loss of strength. The mechanical response of RC elements to reinforcement corrosion has mostly been examined on the basis of a 2D cross-section analysis. However, with this approach it is not possible to represent both corrosion and static loading. In the paper a 3D finite element model of an RC beam with the two actions applied is presented. Rust is represented as an interface between steel and concrete, considering the volumetric expansion of rust.The chloride-induced corrosion of reinforcement used to be represented by Tuutti’s model with initiation and propagation phases. During the initiation phase chlorides penetrate the concrete cover and accumulate around reinforcement bars. The chloride concentration in concrete increases until it reaches a chloride threshold value, causing deterioration of the passive layer of reinforcement. Then the propagation phase begins. During the propagation phase steel has no natural anti-corrosion protection, a corrosion current flows and this induces the production of rust. A growing volume of corrosion products generates stresses in concrete, which leads to cracking, splitting, delamination and loss of strength. The mechanical response of RC elements to reinforcement corrosion has mostly been examined on the basis of a 2D cross-section analysis. However, with this approach it is not possible to represent both corrosion and static loading. In the paper a 3D finite element model of an RC beam with the two actions a...

This paper is devoted to a numerical approach of the biomechanics behavior modeling of a dental implant supported prothesis made up of three elements, and the surrounding bone under the masticatory forces loading. A clinical situation involving both biological (the bone tissue) and non-biological (the three elements of implant prosthesis) materials is simulated. This problem involves fine technical structure details – the threads, tapers, etc with a great impact in masticatory force transmission. Modeling the contact between the implant and the bone tissue is important to a proper bone-implant interface model and implant design. A three-dimensional numerical model is proposed in order to calculate the state of stress and displacement of this complex structure in order to evaluate its stability by determining the risk zones of stress concentration. The results of numerical modeling are in good agreement with other numerical results and clinical casesA comparison between this numerical analysis and clinical cases is performed and a good agreement is obtained.This paper is devoted to a numerical approach of the biomechanics behavior modeling of a dental implant supported prothesis made up of three elements, and the surrounding bone under the masticatory forces loading. A clinical situation involving both biological (the bone tissue) and non-biological (the three elements of implant prosthesis) materials is simulated. This problem involves fine technical structure details – the threads, tapers, etc with a great impact in masticatory force transmission. Modeling the contact between the implant and the bone tissue is important to a proper bone-implant interface model and implant design. A three-dimensional numerical model is proposed in order to calculate the state of stress and displacement of this complex structure in order to evaluate its stability by determining the risk zones of stress concentration. The results of numerical modeling are in good agreement with other numerical results and clinical casesA comparison between this numerical analysis and clinical...

The focus of this paper is the enrichment of solution obtained using finite element method. In Finite Element Method (FEM), results can be improved with the use of two refinement techniques: h-refinement and p-refinement. In h-refinement, number of elements to represent the analytical model is improvised while in p-refinement the degree of the basis functions for the interpolation of field variable and geometry is elevated. In both the cases, entire analysis has to be carried out after changing either mesh or order of interpolation. This process results in increased computational time. Furthermore the earlier results are of no consideration. The proposed methodology involves utilizing the existing results and enriching them through interpolation function. There is no need to carry out the analysis again. To demonstrate the proposed method it is applied to three cases, where it proved to obtain near exact results.The focus of this paper is the enrichment of solution obtained using finite element method. In Finite Element Method (FEM), results can be improved with the use of two refinement techniques: h-refinement and p-refinement. In h-refinement, number of elements to represent the analytical model is improvised while in p-refinement the degree of the basis functions for the interpolation of field variable and geometry is elevated. In both the cases, entire analysis has to be carried out after changing either mesh or order of interpolation. This process results in increased computational time. Furthermore the earlier results are of no consideration. The proposed methodology involves utilizing the existing results and enriching them through interpolation function. There is no need to carry out the analysis again. To demonstrate the proposed method it is applied to three cases, where it proved to obtain near exact results.

The shearing process such as the blanking of sheet metals has been used often to prepare workpieces for subsequent forming operations. The use of FEM simulation is increasing for investigation and optimizing the blanking process. In the current literature a blanking FEM simulations for the limited capability and large computational cost of the three dimensional (3D) analysis has been largely limited to two dimensional (2D) plane axis-symmetry problems. However, a significant progress in modelling which takes into account the influence of real material (e.g. microstructure of the material), physical and technological conditions can be obtained by using 3D numerical analysis methods in this area. The objective of this paper is to present 3D finite element analysis of the ductile fracture, strain distribution and stress in blanking process with the assumption geometrical and physical nonlinearities. The physical, mathematical and computer model of the process are elaborated. Dynamic effects, mechanical coupling, constitutive damage law and contact friction are taken into account. The application in ANSYS/LS-DYNA program is elaborated. The effect of the main process parameter a blanking clearance on the deformation of 1018 steel and quality of the blank’s sheared edge is analyzed. The results of computer simulations can be used to forecasting quality of the final parts optimization.The shearing process such as the blanking of sheet metals has been used often to prepare workpieces for subsequent forming operations. The use of FEM simulation is increasing for investigation and optimizing the blanking process. In the current literature a blanking FEM simulations for the limited capability and large computational cost of the three dimensional (3D) analysis has been largely limited to two dimensional (2D) plane axis-symmetry problems. However, a significant progress in modelling which takes into account the influence of real material (e.g. microstructure of the material), physical and technological conditions can be obtained by using 3D numerical analysis methods in this area. The objective of this paper is to present 3D finite element analysis of the ductile fracture, strain distribution and stress in blanking process with the assumption geometrical and physical nonlinearities. The physical, mathematical and computer model of the process are elaborated. Dynamic effects, mechanical coupl...

Transportation, handling, vibrations can lead to dynamic loadings requiring the characterization of the safety of plastic-bonded explosives (PBX). One of the addressed situations is the fall of explosive on a surface. Knowing that initiation can occur at a lower height during a vertical fall of a projectile on an inclined target than on a horizontal one, devices were developed to determine the critical thresholds. In this paper, data obtained on four HMX and/or TATB-based PBXs using pendulum drop configurations are detailed. Two analytical models are compared to estimate the heat released by friction at the interface. The model proposed in this paper yields the better agreement with data, and with finite element numerical simulations of the oblique impact on a given PBX. Lastly, the mechanical dissipation at the interface is estimated using this model and the simulations. This paper confirms that PBX/target friction cannot be the heating mechanism leading to initiation during oblique impacts.

This paper presents modelling of both single and double-phase powder sintering processes at the macroscopic level. In particular, its constitutive formulation, numerical implementation and numerical tests are described. The macroscopic constitutive model is based on the assumption that the sintered material is a continuous medium. The parameters of the constitutive model for material under sintering are determined by simulation of sintering at the microscopic level using a micro-scale model. Numerical tests were carried out for a cylindrical specimen under hydrostatic and uniaxial pressure. Results of macroscopic analysis are compared against the microscopic model results. Moreover, numerical simulations are validated by comparison with experimental results. The simulations and preparation of the model are carried out by Abaqus FEA - a software for finite element analysis and computer-aided engineering. A mechanical model is defined by the user procedure “Vumat” which is developed by the first author in Fortran programming language. Modelling presented in the paper can be used to optimize and to better understand the process.This paper presents modelling of both single and double-phase powder sintering processes at the macroscopic level. In particular, its constitutive formulation, numerical implementation and numerical tests are described. The macroscopic constitutive model is based on the assumption that the sintered material is a continuous medium. The parameters of the constitutive model for material under sintering are determined by simulation of sintering at the microscopic level using a micro-scale model. Numerical tests were carried out for a cylindrical specimen under hydrostatic and uniaxial pressure. Results of macroscopic analysis are compared against the microscopic model results. Moreover, numerical simulations are validated by comparison with experimental results. The simulations and preparation of the model are carried out by Abaqus FEA - a software for finite element analysis and computer-aided engineering. A mechanical model is defined by the user procedure “Vumat” which is developed by the first author in F...

In this paper the reliability assessment of buckling resistance of steel beam is presented. A number of parameters such as: the boundary conditions, the section height to width ratio, the thickness and the span are considered. The examples are solved using FEM procedures and formulas proposed in the literature and standards. In the case of the numerical models the following parameters are investigated: support conditions, mesh size, load conditions, steel grade. The numerical results are compared with approximate solutions calculated according to the standard formulas. It was observed that for high slenderness section the deformation of the cross-section had to be described by the following modes: longitudinal and transverse displacement, warping, rotation and distortion of the cross section shape. In this case we face interactive buckling problem. Unfortunately, neither the EN Standards nor the subject literature give close-form formulas to solve these problems. For this reason the reliability of the critical bending moment calculations is discussed.In this paper the reliability assessment of buckling resistance of steel beam is presented. A number of parameters such as: the boundary conditions, the section height to width ratio, the thickness and the span are considered. The examples are solved using FEM procedures and formulas proposed in the literature and standards. In the case of the numerical models the following parameters are investigated: support conditions, mesh size, load conditions, steel grade. The numerical results are compared with approximate solutions calculated according to the standard formulas. It was observed that for high slenderness section the deformation of the cross-section had to be described by the following modes: longitudinal and transverse displacement, warping, rotation and distortion of the cross section shape. In this case we face interactive buckling problem. Unfortunately, neither the EN Standards nor the subject literature give close-form formulas to solve these problems. For this reason the reliability of the cri...

This paper presents an attempt of using a finite element method for predicting delamination of a glue laminated timber beam through a cohesive layer. There were used cohesive finite elements, quadratic stress damage initiation criterion and mixed mode energy release rate failure model. Finite element damage was equal to its complete stiffness degradation. Timber material was considered to be an orthotropic with plastic behaviour after reaching bending limit.This paper presents an attempt of using a finite element method for predicting delamination of a glue laminated timber beam through a cohesive layer. There were used cohesive finite elements, quadratic stress damage initiation criterion and mixed mode energy release rate failure model. Finite element damage was equal to its complete stiffness degradation. Timber material was considered to be an orthotropic with plastic behaviour after reaching bending limit.

Tuned mass damper (TMD) has a wide range of applications in the vibration control of footbridges. However, the traditional engineering design method may lead to a mistuned TMD. In this paper, an improved TMD design method based on the model updating is proposed. Firstly, the original finite element model (FEM) is studied and the natural characteristics of the in-service or newly built footbridge is identified by field test, and then the original FEM is updated. TMD is designed according to the new updated FEM, and it is optimized according to the simulation on vibration control effects. Finally, the installation and field measurement of TMD are carried out. The improved design method can be applied to both in-service and newly built footbridges. This paper illustrates the improved design method with an engineering example. The frequency identification results of field test and original FEM show that there is a relatively large difference between them. The TMD designed according to the updated FEM has better vibration control effect than the TMD designed according to the original FEM. The site test results show that TMD has good effect on controlling human-induced vibrations.

In the paper, two kinds of constitutive models for ground and structure were adopted for the nonlinear interaction analysis of the RC cylindrical tank with subsoil. The paper discusses deformational and incremental approaches to a nonlinear FE analysis of soil-structure interaction including the description of behaviour of the RC structure and the subsoil under short-term loading. Moreover, a non-linear elastic-brittle-plastic analysis of RC axisymmetric structures using finite element iterative techniques is presented. The constitutive laws for concrete and subsoil are developed in compliance with the deformational and plastic flow theories of plasticity. Two examples of an FE analysis of soil-structure interaction were performed and the results were analysed.

This Paper combines the Dugdale’s Approach with Extended finite element method (XFEM) in order to estimate the Plastic zone length (PZL) for a straight edge cracked plate (SECP) under uniaxial tensile loading condition. Dugdale utilized a different approach to evaluate the PZL by nullifying the effect of singularity at the tip of the virtually extended crack by the applying a uniform pressure which is equal to the yielding stress. XFEM is utilized for analyzing SECP as it is more efficient and accurate as compared to other conventional numerical tools. In XFEM, crack can be extended without any re-meshing because elements near crack interface need not to conform the crack geometry.PZL for SECP is evaluated for crack length, a, varying in the range of 0.01 to 0.05 (m) in steps of 0.01 and load intensity (σ0/Y) ranging from 0.1 to 0.5 in steps of 0.1. Crack Position (h/H) is also varied ranging from 0 to 0.8 in step of 0.2 in order to analyse its effect on PZL. MATLAB is employed for Extended Finite element analysis of SECP under Plane stress condition. Four node Quadrilateral elementsare used for extended finite element analysis. The numerical results are validated by the experimental results from the available literature.This Paper combines the Dugdale’s Approach with Extended finite element method (XFEM) in order to estimate the Plastic zone length (PZL) for a straight edge cracked plate (SECP) under uniaxial tensile loading condition. Dugdale utilized a different approach to evaluate the PZL by nullifying the effect of singularity at the tip of the virtually extended crack by the applying a uniform pressure which is equal to the yielding stress. XFEM is utilized for analyzing SECP as it is more efficient and accurate as compared to other conventional numerical tools. In XFEM, crack can be extended without any re-meshing because elements near crack interface need not to conform the crack geometry.PZL for SECP is evaluated for crack length, a, varying in the range of 0.01 to 0.05 (m) in steps of 0.01 and load intensity (σ0/Y) ranging from 0.1 to 0.5 in steps of 0.1. Crack Position (h/H) is also varied ranging from 0 to 0.8 in step of 0.2 in order to analyse its effect on PZL. MATLAB is employed for Extended Finite element...

Fuel efficiency requirements demand lightweight construction of vehicle body parts. The usage of advanced high strength steels permits a reduction of sheet thickness while still maintaining the overall strength required for crash safety. However, damage, internal defects (voids, inclusions, micro fractures), microstructural defects (varying grain size distribution, precipitates on grain boundaries, anisotropy) and surface defects (micro fractures, grooves) act as a concentration point for stress and consequently as an initiation point for failure both during deep drawing and in service. Considering damage evolution in the design of car body deep drawing processes allows for a further reduction in material usage and therefore body weight. Preliminary research has shown that a modification of load paths in forming processes can help mitigate the effects of damage on the material.This paper investigates the load paths in Nakajima tests of a DP800 dual phase steel to research damage in deep drawing processes. Investigation is done via a finite element model using experimentally validated material data for a DP800 dual phase steel. Numerical simulation allows for the investigation of load paths with respect to stress states, strain rates and temperature evolution, which cannot be easily observed in physical experiments. Stress triaxiality and the Lode parameter are used to describe the stress states. Their evolution during the Nakajima tests serves as an indicator for damage evolution. The large variety of sheet metal forming specific load paths in Nakajima tests allows a comprehensive evaluation of damage for deep drawing. The results of the numerical simulation conducted in this project and further physical experiments will later be used to calibrate a damage model for simulation of deep drawing processes.Fuel efficiency requirements demand lightweight construction of vehicle body parts. The usage of advanced high strength steels permits a reduction of sheet thickness while still maintaining the overall strength required for crash safety. However, damage, internal defects (voids, inclusions, micro fractures), microstructural defects (varying grain size distribution, precipitates on grain boundaries, anisotropy) and surface defects (micro fractures, grooves) act as a concentration point for stress and consequently as an initiation point for failure both during deep drawing and in service. Considering damage evolution in the design of car body deep drawing processes allows for a further reduction in material usage and therefore body weight. Preliminary research has shown that a modification of load paths in forming processes can help mitigate the effects of damage on the material.This paper investigates the load paths in Nakajima tests of a DP800 dual phase steel to research damage in deep drawing processes....

In order to improve the design reliability of the double layer porous asphalt pavement, the 3D seepage finite element method was used to study the drainage capacity of double layer PAC pavements with different geometric parameters. It revealed that the effect of pavement drainage length, slope, permeability coefficient and structure design on the drainage capacity. The research of this paper can provide reference for the design of double layer porous asphalt pavement in different rainfall intensity areas, and provide guides for the related engineering design.In order to improve the design reliability of the double layer porous asphalt pavement, the 3D seepage finite element method was used to study the drainage capacity of double layer PAC pavements with different geometric parameters. It revealed that the effect of pavement drainage length, slope, permeability coefficient and structure design on the drainage capacity. The research of this paper can provide reference for the design of double layer porous asphalt pavement in different rainfall intensity areas, and provide guides for the related engineering design.

This paper presents the characteristics of the process of longitudinal rolling of shafts and the geometry of the working section of forming rollers with a secant profile. In addition, the analytical formulae defining the geometry of a roller profile were determined. The experiments were carried out on shafts made of S235JR and C45 structural steels and the MSC.Marc + Mentat program was used for the numerical analysis of the rolling process based on the finite element method. The paper analyses the effect of roller geometry on the changes in value of the widening coefficient and the diameter reduction coefficient for the first forming passage. It was found that the mechanical properties of the shaft material have a slight influence on the widening coefficient. The value of the widening coefficient of the shaft increases with increase in the initial diameter of the shaft. Increasing shaft diameter causes an increase of strain gradient on the cross-section of the shaft.

Scaffolding is a specific construction with high susceptibility to low frequency vibrations. The numerical model of scaffolding presented in this paper contains real imperfections received from geodetic measurements of real construction. Boundary conditions were verified on the basis of measured free vibrations. A simulation of a man walking on penultimate working level as a dynamic load variable in time was made for verified model. The paper presents procedure for a choice of selected parameters of the scaffolding FEM model. The main aim of analysis is the best projection of the real construction and correct modeling of worker walking on the scaffolding. Different boundary conditions are considered, because of their impact on construction vibrations. Natural vibrations obtained from FEM calculations are compared with free vibrations measured during in-situ tests. Structure accelerations caused by walking human are then considered in this paper. Methodology of creating numerical models of scaffoldings and analysis of dynamic effects during human walking are starting points for further considerations about dynamic loads acting on such structures and effects of these loads to construction and workers, whose workplaces are situated on the scaffolding.

With the progress of China’s nuclear power industry, nuclear power plant valve products is in a period of rapid development, high performance, low cost, short cycle of design requirements for nuclear power valve is proposed, so there is an urgent need for advanced digital design method and integrated design platform to provide technical support. Especially in the background of the nuclear power plant leakage in Japan, it is more practical to improve the design capability and product performance of the nuclear power valve. The finite element numerical analysis is a common and effective method for the development of nuclear power valves. Nuclear power valve has high safety, complexity of valve chamber and nonlinearity of seal joint surface. Therefore, it is urgent to establish accurate prediction models for earthquake prediction and seal failure to meet engineering accuracy and calculation conditions. In this paper, a general method of finite element modeling for nuclear power valve assembly and key components is presented, aiming at revealing the characteristics and rules of finite element modeling of nuclear power valves, and putting forward aprecision control strategy for finite element models for nuclear power valve characteristics analysis.With the progress of China’s nuclear power industry, nuclear power plant valve products is in a period of rapid development, high performance, low cost, short cycle of design requirements for nuclear power valve is proposed, so there is an urgent need for advanced digital design method and integrated design platform to provide technical support. Especially in the background of the nuclear power plant leakage in Japan, it is more practical to improve the design capability and product performance of the nuclear power valve. The finite element numerical analysis is a common and effective method for the development of nuclear power valves. Nuclear power valve has high safety, complexity of valve chamber and nonlinearity of seal joint surface. Therefore, it is urgent to establish accurate prediction models for earthquake prediction and seal failure to meet engineering accuracy and calculation conditions. In this paper, a general method of finite element modeling for nuclear power valve assembly and key compone...

The paper deals with mode-frequency analysis of a simply-supported equal-sided sector of a laminated doubly curved shell. The problem is modelled using finite element package program ANSYS. The formulation based on first-order shear deformation theory. Four elements are chosen along each edge of the sector. The reduced method of eigenvalue solution is chosen for the undamped mode-frequency analysis. The results are given in graphical form.The paper deals with mode-frequency analysis of a simply-supported equal-sided sector of a laminated doubly curved shell. The problem is modelled using finite element package program ANSYS. The formulation based on first-order shear deformation theory. Four elements are chosen along each edge of the sector. The reduced method of eigenvalue solution is chosen for the undamped mode-frequency analysis. The results are given in graphical form.

The paper presents an optimal design of UAV wing, made of composite materials. The aim of the optimization is to improve strength and stiffness together with reduction of the weight of the structure. Three different types of functionals, which depend on stress, stiffness and the total mass are defined. The paper presents an application of the in-house implementation of the evolutionary multi-objective algorithm in optimization of the UAV wing structure. Values of the functionals are calculated on the basis of results obtained from numerical simulations. Numerical FEM model, consisting of different composite materials is created. Adequacy of the numerical model is verified by results obtained from the experiment, performed on a tensile testing machine. Examples of multi-objective optimization by means of Pareto-optimal set of solutions are presented.

This paper represents a structural analysis of hatch cover of a container vessel having a capacity of 2400 DWT using finite element method. The objective of this paper is to determine the Von Mises stress and to analyze the factor of safety for different structural members. The objective also includes reducing the steel weight by keeping the reasonable factor of safety. Firstly the hatch cover model was designed according to Germanischar Lloyd (GL) rulebook. Heaving acceleration was taken into account during load calculation. Then the structural analysis of the hatch cover model was done by the finite element analysis (FEA). In this study, meshing was done using quadrilateral shell element. The Von Mises stress was compared with the yield stress of the hatch cover material. The hatch cover model was modified several times to find the reasonable factor of safety along with lesser steel weight. The modification of modeling was done by changing the thickness and the dimensions of different structural members, including insert plate at the container shoe. This study can be applied to predict structural failure under any loading condition.

This paper proposed a dynamic fatigue reliability method of contact wires based on dynamic simulation of high-speed pantograph-catenary. Firstly, the Weibull distribution was adopted to describe the fatigue life of contact wires so as to build the fatigue reliability model of contact wires. And then 10 finite element models of elastic chain type for contact networks were set up with the EN50367 parameter. Thereafter the stress time of the weakest unit on contact wires was calculated through the finite element simulation. Secondly, the mean value and amplitude of each stress cycle were calculated by means of rain flow counting method, and these values were put into the reliability model to draw the changing curve of the fatigue reliability of contact wires with time. The numerical example showed that the fatigue reliability of contact wires would be less than 0.98 when these wires were used for more than 10 years. The method provided in this paper can be used to estimate the fatigue reliability of contact ...

Due to extensive usage of corrugated web in construction, this paper performs finite element analysis to investigate the web thickness effects on the bending behaviour of Triangular Web Profile (TRIWP) steel section. A TRIWP steel section which are consists two flanges attached to a triangular profile web plate. This paper analyzes two categories of TRIWP steel sections which are D×100×6×3 mm and D×75×5×2 mm. It was observed that for steel section D×100×6×3 mm (TRIWP1), the deflection about minor and major axis increased as the span length increased. Meanwhile, the deflection about major axis decreased when depth of the web increased. About minor axis, the deflection increased for 3m and 4m span, while the deflection at 4.8m decreased with increment the depth of web. However, when the depth of the web exceeds 250mm, deflection at 3m and 4m were increased. For steel section D×75×5×2 mm (TRIWP2), the result was different with TRIWP1 steel section, where the deflection in both major and minor directions increased with the increment of span length and decreased with increment the depth of web. It shows that the deflection increased proportionally with the depth of web. Therefore, deeper web should be more considered because it resulted in smaller deflection.

This paper presents a study on the ultimate load behaviour of corrugated girder webs under shear loading following nonlinear finite element analysis. Sensitivity analyses conducted herein are numbers of corrugation wave, elements density, initial imperfection and material nonlinearities. This paper aimed to investigate the influence of this sensitivity to the ultimate shear load, buckling and post-buckling behaviours of the corrugated web girder under shear loading condition. Two web thicknesses have been considered in the study, while flanges were designed to be strong enough to ensure the shear governed. The corrugated profiled geometry remained constant for all models. The ultimate shear loads were reported and compared with the existing theoretical design. Based on the numerical results, this sensitivity analysis does not have a major effect on ultimate shear load and post-buckling behaviours. However, when the girder is controlled by elastic buckling, the shear resistance is higher compared to the se...

As an important part of the valve opening and closing controller in engine, camshaft has high machining accuracy requirement in designing. Taking the high-speed camshaft grinder spindle system as the research object and the spindle system performance as the optimizing target, this paper firstly uses Solidworks to establish the three-dimensional finite element model (FEM) of spindle system, then conducts static analysis and the modal analysis by applying the established FEM in ANSYS Workbench, and finally uses the design optimization function of the ANSYS Workbench to optimize the structure parameter in the spindle system. The study results prove that the design of the spindle system fully meets the production requirements, and the performance of the optimized spindle system is promoted. Besides, this paper provides an analysis and optimization method for other grinder spindle systems.

This paper describes the testing of single-edge notched bend (SENB) specimens, which are used for fracture toughness tests, and the ductile crack initiation from the notch tip of the specimens. All of the specimens exhibited brittle fracture with relatively large ductile crack growth (from 1.0 to 4.8 mm). The paper also shows the ductile crack growth simulation using a damage model (Bonora model) for finite element analysis (FEA). FEA reproduced ductile crack growth observed in the SENB tests and the analysis results showed the effects of the ductile crack growth rate on stress distribution around the crack tips. In addition, the value of the Weibull stress was calculated in the paper, and the Weibull stress slightly decreased if the model had a higher ductile crack growth rate as compared with the model that had a lower ductile crack growth rate.

The paper deals with local stability of the thin-walled compressed flange of channel columns and beams made of aluminum alloy. The aim of paper is to find critical stress of local buckling of the flange member taking into account the web-flange interaction in linear and nonlinear elastic range of the member material. The governing differential equation of the problem is derived with aid of the principle of stationary total potential energy. The equation solution leads to the critical buckling stress and assessment of the number of half-waves in linear elastic range of the member material. Taking into account these results the analytical formula of the critical buckling stress in nonlinear elastic range is established using the tangent modulus theory and the Ramberg-Osgood stress-strain relationship. Finally the analytical results for simply supported members are compared with the FEM solutions and good agreement is observed.

Geometric in design is much related with our life. Each of the geometrical structure interacts with each other. The overall shape of an object contains other shape inside, and there shapes create a relationship between each other in space. Besides that, how geometry relates to the function of the object have to be considerate. In this project, the main purpose was to design the geometrical shape of modular furniture with the shrinking of Polyethylene Terephthalate (PET) jointing system that has good strength when applied load on it. But, the goal of this paper is focusing on the analysis of Static Cases by FEM of the hexagonal structure to obtain the strength when load apply on it. The review from the existing product has many information and very helpful to finish this paper. This project focuses on hexagonal shape that distributed to become a shelf inspired by honeycomb structure. It is very natural look and simple in shape and its modular structure more easily to separate and combine. The method discus...

New approach to static analysis of thin non-rectangular arbitrarily loaded plates, called the macroelement method, has been developed in this paper. Macroelement is a rectangular plate which entirely contains real plate. The mathematical model of macroelement was built. The equilibrium equations are performed for macroelement and boundary conditions are written on the line corresponding to contour of real plate in the nodes which are zero points of trigonometric functions, included in the macroelement model. The load is applied only to separate nodes on the surface of real plate, whereas the complement of a plate to macroelement is unloaded. Analysis of construction is reduced to solving a system of linear algebraic equations. The method provides better accuracy compared to finite element method and requires less equations. There is trapeze plate clamped at inclined edge and simply supported at opposite one considered in this paper. The other edges of the plate are free. Uniformly distributed load on the ...

The paper presents a mathematical and computer modeling of effective properties of porous piezoelectric materials of three types: with ordinary porosity, with metallized pore surfaces, and with nanoscale porosity structure. The described integrated approach includes the effective moduli method of composite mechanics, simulation of representative volumes, and finite element method.The paper presents a mathematical and computer modeling of effective properties of porous piezoelectric materials of three types: with ordinary porosity, with metallized pore surfaces, and with nanoscale porosity structure. The described integrated approach includes the effective moduli method of composite mechanics, simulation of representative volumes, and finite element method.

Sheet metal forming (SMF) simulations are used extensively throughout the development phase of industrial stamping dies. In these SMF simulations, the die and press are normally considered as rigid. Previous research has however shown that elastic deformation in these parts has a significant negative impact on process performance. This paper demonstrates methods for counteracting these negative effects, with a high potential for improved production support and a reduced lead time through a shorter try-out process. A structural finite element model (FE-model) of a simplified die is studied. To account for elastic deformation, the blankholder surfaces are first virtually reworked by adjusting the nodal positions on the die surfaces attaining a pressure distribution in accordance to the design phase SMF simulations with rigid surfaces. The elastic FE-model with reworked surfaces then represents a stamping die in running production. The die is now assumed to be exposed to changed process conditions giving an undesired blankholder pressure distribution. The changed process conditions could for example be due to a change of press line. An optimization routine is applied to compensate the negative effects of the new process conditions. The optimization routine uses the contact forces acting on the shims of the spacer blocks and cushion pins as optimization variables. A flexible simulation environment using MATLAB and ABAQUS is used. ABAQUS is executed from MATLAB and the results are automatically read back into MATLAB. The suggested optimization procedure reaches a pressure distribution very similar to the initial distribution assumed to be the optimum, and thereby verifying the method. Further research is needed for a method to transform the calculated forces in the optimization routine back to shims thicknesses. Furthermore, the optimization time is relatively long and needs to be reduced in the future for the method to reach its full potential.Sheet metal forming (SMF) simulations are used extensively throughout the development phase of industrial stamping dies. In these SMF simulations, the die and press are normally considered as rigid. Previous research has however shown that elastic deformation in these parts has a significant negative impact on process performance. This paper demonstrates methods for counteracting these negative effects, with a high potential for improved production support and a reduced lead time through a shorter try-out process. A structural finite element model (FE-model) of a simplified die is studied. To account for elastic deformation, the blankholder surfaces are first virtually reworked by adjusting the nodal positions on the die surfaces attaining a pressure distribution in accordance to the design phase SMF simulations with rigid surfaces. The elastic FE-model with reworked surfaces then represents a stamping die in running production. The die is now assumed to be exposed to changed process conditions giving an ...

This paper presents the first results of a study aimed at evaluate the effectiveness of a strengthening technique able to connect masonry elements, stitching them, based on the use of basalt fibre ropes. To assess the effectiveness of proposed technique, experimental and FEM analysis has been performed. The reproduced masonry is the “three-leaf wall”, where an inner core of rubble material is included between two outer brick shell, a masonry typology often found in Italian historical building heritage. The results indicate the efficacy of this dry retrofitting system, increasing the performance of masonry wall specimens.This paper presents the first results of a study aimed at evaluate the effectiveness of a strengthening technique able to connect masonry elements, stitching them, based on the use of basalt fibre ropes. To assess the effectiveness of proposed technique, experimental and FEM analysis has been performed. The reproduced masonry is the “three-leaf wall”, where an inner core of rubble material is included between two outer brick shell, a masonry typology often found in Italian historical building heritage. The results indicate the efficacy of this dry retrofitting system, increasing the performance of masonry wall specimens.

Lamb waves are widely used in nondestructive testing (NDT) and structural health monitoring (SHM) for its obvious advantages, such as good directionality, longer-range propagation and lower loss etc. However, it is difficult to analysis and to interpret the echo signals because of its multi-modes and dispersion. In this paper, the properties of single-mode Lamb waves which were excited by double EMAT were studied based on the principles of multi-modes and the characteristics of wave structure. Simulation results show that the double transducer excitation structure can stimulate single-mode Lamb waves and eliminate the extra modes, which are produced by modal conversion at ends of the specimen. The single-mode excitation of Lamb waves is beneficial to reduce the difficulty of signal processing and provide reliable information to locate the defect. The researches in this paper can be used as a theoretical basis to design double transducer excitation system.

This paper discusses a numerical investigation of thickness changes of Dyneema HB80, a cross-ply thermoplastic lamina, during a helmet thermoforming process. The main mode of deformation during the preform phase of manufacture is in-plane shearing of the fabric. A laminate undergoes varying degrees of shear to conform to the geometric variations over the surface of the preform shape. Decreases in areal coverage that occur with increases in the local shear angle will lead to a resulting increase in local thickness. During the consolidation phase, multiple preform layers are compressed in a set of matched tools, and the compounding of the thickness variations can adversely affect the uniformity of pressure distribution between matched die tooling. Pressure variations over the surface of the part can lead to incomplete consolidation of the ply stack, as well as weakened, resin-rich areas. Because wrinkling of the composite reinforcement, incomplete consolidation and resin-rich areas can result in a compromised structural performance, it is important that the manufacturing process be well understood so it can be designed to mitigate formation of such defects. In the current work, the material properties derived from shear, bending and tensile tests are implemented in a finite element model of the cross-ply lamina. The finite element model uses a hybrid discrete mesoscopic approach, and deep-draw forming of the material is simulated to investigate its formability to a hemispherical geometry. Thickening of the lamina resulting from shear deformation is investigated and incorporated into models single-layer preform simulations. The simulation results are used to inform the design of multiple-layer preforms to mitigate the development of thin regions and out-of-plane waves to ensure complete, uniform consolidation.This paper discusses a numerical investigation of thickness changes of Dyneema HB80, a cross-ply thermoplastic lamina, during a helmet thermoforming process. The main mode of deformation during the preform phase of manufacture is in-plane shearing of the fabric. A laminate undergoes varying degrees of shear to conform to the geometric variations over the surface of the preform shape. Decreases in areal coverage that occur with increases in the local shear angle will lead to a resulting increase in local thickness. During the consolidation phase, multiple preform layers are compressed in a set of matched tools, and the compounding of the thickness variations can adversely affect the uniformity of pressure distribution between matched die tooling. Pressure variations over the surface of the part can lead to incomplete consolidation of the ply stack, as well as weakened, resin-rich areas. Because wrinkling of the composite reinforcement, incomplete consolidation and resin-rich areas can result in a compromis...

The paper describes the performance evaluation of a retrofit historical multi-span (RC) deck arch bridge analyzed with in situ tests, dynamic identification and FEM analysis. The peculiarity of this case study lies in the structural typology of “San Felice” bridge, an historical concrete arch bridge built in the early 20th century, a quite uncommon feature in Italy. The preservation and retrofit of historic cultural heritage and infrastructures has been carefully analyzed in the international codes governing seismic response. A complete survey of the bridge was carried out prior to sketching a drawing of the existing bridge. Subsequently, the study consists in four steps: material investigation and dynamic vibration tests, FEM analysis and calibration, retrofit assessment, pushover analysis. The aim is to define an innovative approach to calibrate the FEM analysis through modern experimental investigations capable of taking structural deterioration into account, and to offer an appropriate and cost-effective retrofitting strategy.The paper describes the performance evaluation of a retrofit historical multi-span (RC) deck arch bridge analyzed with in situ tests, dynamic identification and FEM analysis. The peculiarity of this case study lies in the structural typology of “San Felice” bridge, an historical concrete arch bridge built in the early 20th century, a quite uncommon feature in Italy. The preservation and retrofit of historic cultural heritage and infrastructures has been carefully analyzed in the international codes governing seismic response. A complete survey of the bridge was carried out prior to sketching a drawing of the existing bridge. Subsequently, the study consists in four steps: material investigation and dynamic vibration tests, FEM analysis and calibration, retrofit assessment, pushover analysis. The aim is to define an innovative approach to calibrate the FEM analysis through modern experimental investigations capable of taking structural deterioration into account, and to offer an appropriate and cost-effect...

According to available literature, it is assumed that outer packaging container, which is usually made of corrugated cardboard, does not influence the mitigation of the impact effects, thus in the designing process of packaging system the outer packaging is skipped. The purpose of this paper is to verify the above assumption, including determination of the influence of the 5-layer cardboard on the properties of structures that consist of that cardboard and polyethylene foam. Verification is performed with the use of the finite element method. To apply this method the dynamic compression curve of cushioning material is required. Therefore in the paper it is also presented the modified method to determine the curve.

Thermo-mechanical numerical modelling and simulation of extrusion processes faces several serious challenges. Large plastic deformations in combination with a strong coupling of thermal with mechanical effects leads to a high numerical demand for the solution as well as for the handling of mesh distortions. The two numerical methods presented in this paper also reflect two different ways to deal with mesh distortions. Lagrangian Finite Element Methods (FEM) tackle distorted elements by building a new mesh (called re-meshing) whereas Arbitrary Lagrangian Eulerian (ALE) methods use an “advection” step to remap the solution from the distorted to the undistorted mesh. Another difference between conventional Lagrangian and ALE methods is the separate treatment of material and mesh in ALE, allowing the definition of individual velocity fields. In theory, an ALE formulation contains the Eulerian formulation as a subset to the Lagrangian description of the material. The investigations presented in this paper were dealing with the direct extrusion of a tube profile using EN-AW 6082 aluminum alloy and a comparison of experimental with Lagrangian and ALE results. The numerical simulations cover the billet upsetting and last until one third of the billet length is extruded. A good qualitative correlation of experimental and numerical results could be found, however, major differences between Lagrangian and ALE methods concerning thermo-mechanical coupling lead to deviations in the thermal results.

End-plate connections with preloaded high strength bolts represent a convenient, fast and accurate solution for beam-to-column joints. The behavior of framework joints build up with this type of connection are sensitive dependent on geometrical and material characteristics of the elements connected. This paper presents results of parametric analyses on the behavior of a bolted extended end-plate connection using finite element modeling program Abaqus. This connection was experimentally tested in the Laboratory of Faculty of Civil Engineering from Cluj-Napoca and the results are briefly reviewed in this paper. The numerical model of the studied connection was described in detail in [1] and provides data for this parametric study.

This paper presents an experimental investigation of a statically monotonic loaded extended end-plate connection, with preloaded high strength bolts, that was carried out at Laboratory of Faculty of Civil Engineering from Cluj-Napoca. A finite element model using the software package Abaqus [1] was developed in parallel. In order to calibrate the numerical model, the results were analyzed on the basis of moment-rotation curves, stress distribution state and the failure mode of connection. Then, a study was conducted on the numerical model by using a high strength steel (HSS) and changing the stiffness and strength characteristics of some elements. Validation of the numerical modeling was performed against the experimental results and it can be seen that good agreements exist in general.This paper presents an experimental investigation of a statically monotonic loaded extended end-plate connection, with preloaded high strength bolts, that was carried out at Laboratory of Faculty of Civil Engineering from Cluj-Napoca. A finite element model using the software package Abaqus [1] was developed in parallel. In order to calibrate the numerical model, the results were analyzed on the basis of moment-rotation curves, stress distribution state and the failure mode of connection. Then, a study was conducted on the numerical model by using a high strength steel (HSS) and changing the stiffness and strength characteristics of some elements. Validation of the numerical modeling was performed against the experimental results and it can be seen that good agreements exist in general.