Search

Castellated beams are well contemporarily ascribable to their structural applications. The Castellated beams are manufactured by fragmenting hot-formed rolled section that is of I shape in then it is welded together. The numerical analysis is performed using ABAQUS software. Consequently flexural, shear behavior of Castellated beams, various size and shape of openings provided, depth of openings, usage of different kinds of stiffeners, columns with and without web openings are the attempts made up in different journal papers and he researchers. It is also found that the Finite element analysis of the beam shows better results. [ABSTRACT FROM AUTHOR]

The main objective of the research work is to present the free vibration analysis of plates composed of one of the materials that have good performance and can be applied in many fields like buildings. Material that has such properties is Functionally Graded Material (FGM). FGM consists of a mixture of ceramics and metals through varying volume fractions, ceramic material as a heat barrier at the high-temperature side, and metal material with rigid properties and high conductivity at the low-temperature side. In this paper, the FGM plate is investigated using the finite element method. We use 3-node Triangular Mixed Interpolation of Tensorial Components (MITC3), widely used by researchers or commercial software. The MITC3 element is a triangular element that gives good performance to analyze plate problems, especially isotropic plate problems. We performed the numerical analysis to examine the performance and convergence behavior of the MITC3 FGM plate element in the case of rectangular plates with varying length to width ratios, and the results are compared with the reference solution. [ABSTRACT FROM AUTHOR]

Members of double-symmetrical open cross-sections are widely used as columns in steel structures. In many cases columns are subjected not only to axial force but also local transverse force due to effect of beams connected to the columns. It results in compression in the column web that should be verified in the structural design. Current standard for design of joints in steel structures provides basic information for verification of this joint component. The design resistance of column web in compression is given as yielding resistance or, based on relative slenderness of the web, buckling resistance which takes into account buckling and crippling of the web that are considered using reduction factor. The complex behaviour of the column web in compression is affected by number of aspects, e.g. structural solution of the joint (bolted, welded, with or without end plate), level of normal stress resulting from axial force or possible interaction with shear. The paper focuses on selected aspects influencing the resistance of the column web in transverse compression and summarizes results of advanced geometrically and materially nonlinear numerical analysis which are compared with results determined using provisions in the standards. The numerical analysis was performed using computation system based on finite element method. As it is considered that the resistance of the column web in transverse compression is influenced also by the geometric properties of the cross-section including geometry of the flange-web transition, both rolled and welded cross-sections with various values of web slenderness were selected for the analysis. Along with evaluation of the results obtained in the frame of the study, suitability of different types of numerical models for investigation of this problem is discussed. [ABSTRACT FROM AUTHOR]

Cold-formed steel product sections are abundantly utilized in the metal buildings, constructions and Industries for more than four decades. These products are found more in general in every form of working environment due to their flexibility, availability, market value, increased weight and strength ratio, easy fabrication and so on. The highly notable application is that these steel sections are obtainable in varied shapes that we can avail predominantly according to the need. The finite element method is specifically technique of numerical analysis to pertain mere elucidations to massive range of engineering crisis. This paper depicts an analysis by numerical method with bending operation of cold-formed steel built-up sections. The results obtained through the experiment are conformed through finite element analysis with ANSYS R2 Software and Manual designs. The investigational results procured are better submission to the analytical outcome. [ABSTRACT FROM AUTHOR]

This paper is devoted to numerical analysis of plaster detachment and numerical experiments for determination of the appropriate material parameters. Interaction between the plaster and masonry is described with the help of interface finite elements which are equipped with traction-displacement relationship. Laboratory tests were introduced in order to determine the shear capacity of the masonry-plaster connection. Unfortunately, variability of measured behaviour was very large and additional tests are needed. [ABSTRACT FROM AUTHOR]

This paper deals with a slat chain conveyor for the transport of rock materials in very severe abrasive conditions. An actual case from practice is discussed and analysed. To clarify the fatigue damage of the chain link material, the finite element method (FEM) is applied. For the experimentally recorded cycle of chain loading, numerical analysis has been performed and data for the damage of the link material are presented. Fatigue analysis is performed by ANSYS nCode DesignLife under different loading cases. FEM results show, that the fatigue crack of the link starts from region with high values of the stresses, established by experiment. [ABSTRACT FROM AUTHOR]

A finite element analysis on crash box of an automotive bumper system is presented in the paper to investigate the energy absorption of the component with and without foam-filled steel sheet metal tubes of different thicknesses for crashing or low-velocity impact analysis. The energy absorption capacity of the crash box for crashing is evaluated for different design changes of the foams-tube structure and compared the results without foam. By changing the different foam materials, various designs are proposed and simulated for maximum energy absorption. Altair Hyperworks is used for preprocessing and post-processing and Radios solver is used to run the analysis. A reasonable agreement is obtained in the results of the analytical and numerical methods. The results indicate that the energy absorption of a foam-filled crash box structure is superior to the crash box without foam. [ABSTRACT FROM AUTHOR]

The following paper aims to provide a detailed analysis of the effect of different cutting speeds in the face milling of AISI 1045 steel using coated tool. Simulations would aid in solving problems associated with experiments, leading to reduced costs and risks. DEFORM 3D is a commercially used simulation software capable of implementing machining simulations using the theory of finite element modelling. A conventional DEFORM 3D milling model has been prepared for the analysis of cutting forces and chip formation and the simulation has been carried out for two conditions. The temperature and force parameters were analyzed after carrying out the experiment and simulation under the influence of different machining and environmental conditions. The results of the simulation revealed that the predicted values of FEA possess good accuracy. [ABSTRACT FROM AUTHOR]

Steel coupling beam is a substantial member in hybrid coupled walls system that greatly enhance the strength and the energy dissipation capacity of the system compared to coupled walls linked by convention reinforced coupling beams and diagonally reinforced coupling beams. To enhance these characteristics even more, a corrugated web may be used instead of the traditional flat web. This paper presents a numerical analysis using finite elements software (ABAQUS) to investigate the nonlinear behavior of both types of steel coupling beams (with flat web and with corrugated web). The effect of initial imperfection on the nonlinear behavior of steel coupling beams was taken into account. The results were compared with the available experimental data of steel coupling beams with the flat web. Good agreement was noticed between the experimental and the numerical results. Among the conclusions drawn in this study is that using a corrugated web as an alternative to a flat web may increase both the strength and the energy dissipation of the steel coupling beams. [ABSTRACT FROM AUTHOR]

Since the first paper published in 2005 Isogeometric Analysis (IGA) has gained strong interest and found applications in many engineering problems. Despite the advancement of the method, there are still far fewer software implementations comparing to Finite Element Method. The paper presents an approach to the development of data structures that can support multi-region IGA with local mesh refinement (patch-based) and possible application in IGA-FEM models. The purpose of this paper is to share original design concepts, that authors have created while developing an IGA package, which other researchers may find beneficial for their own simulation codes. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The differential eigenvalue problem describing eigenvibrations of a simply supported beam with an attached load is investigated. This problem has an increasing sequence of positive simple eigenvalues with a limit point at infinity. To the sequence of eigenvalues, there corresponds a complete orthonormal system of eigenfunctions. We formulate a limit differential eigenvalue problem and prove the convergence of the eigenvalues and eigenfunctions of the initial problem to the corresponding eigenvalues and eigenfunctions of the limit problem as load mass tending to infinity. The original differential eigenvalue problem is approximated by the finite difference method on a uniform grid. Error estimates for approximate eigenvalues and eigenfunctions are established. The theoretical results are illustrated by numerical experiments for a model problem. Investigations of this paper can be extended to the cases of more complicated and important problems on eigenvibrations of plates and shells with attached loads. [ABSTRACT FROM AUTHOR]

The nonlinear second-order differential eigenvalue problem describing eigenvibrations of a bar with elastically attached load is investigated. The existence of an increasing sequence of positive simple eigenvalues with a limit point at infinity is established. To the sequence of eigenvalues, there corresponds a system of normalized eigenfunctions. The initial nonlinear differential eigenvalue problem is approximated by the finite element method on a uniform grid. The accuracy of approximate solutions is studied. The investigations in the present paper can be extended to the cases of more complicated and important problems on eigenvibrations of beams, plates, and shells with elastically attached loads. [ABSTRACT FROM AUTHOR]

The paper focuses on numerical solution of a nonlinear aeroelastic problem. The classical approach of linearized aerodynamic forces is compared to the numerical approximation of the coupled fluid-structure problem. In the second case the finite element method is used for solution of the incompressible Navier-Stokes equations and coupled with the non-linear motion equations of a flexibly supported airfoil. The obtained results are compared to the linearized approach approximations. The influence of the nonlinear terms is discussed. [ABSTRACT FROM AUTHOR]

In this paper, the numerical analysis and computer simulation of deep drawing process has been presented. The incremental model of the process in updated Lagrangian formulation with the regard of the geometrical and physical nonlinearity has been evaluated by variational and the finite element methods. The Frederic Barlat’s model taking into consideration the anisotropy of materials in three main and six tangents directions has been used. The work out application in Ansys/Ls-Dyna program allows complex step by step analysis and prognoses: the shape, dimensions and state stress and strains of drawpiece. The paper presents the influence of selected anisotropic parameter in the Barlat’s model on the drawpiece shape, which includes: height, sheet thickness and maximum drawing force. The important factors determining the proper formation of drawpiece and the ways of their determination have been described. [ABSTRACT FROM AUTHOR]

The combination of plastic and creep analysis formulation are developed in this paper. The boundary element method and the finite element method are applied in plates in order to do the numerical analysis. This new approach is developed to combine the constitutive equation for time hardening creep and the constitutive equation for plasticity, which is based on the von Mises criterion and the Prandtl-Reuss flow. The implementation of creep strain in the formulation is achieved through domain integrals. The creep phenomenon takes place in the domain which is discretized into quadratic quadrilateral continuous and discontinuous cells. The creep analysis is applied to metals with a power law creep for the secondary creep stage. Results obtained for some models studied are compared to those published in the literature. The uncertainties in both geometric and mechanical properties are considered in order to obtain the structural response. The approach is illustrated in a plate subjected to incremental load, results show that there are high probabilities of exceeding the damage states, w, equal to 0.3, 0.6, 1.2, 1.8 and 2.4 while for values of w equal to 3.0, 3.6, 4.2, 4.8, 5.4 and 6.0 these probabilities are low. The obtained results are in good agreement and evinced that the Boundary Element Method could be a suitable tool to deal with combined nonlinear problems. [ABSTRACT FROM AUTHOR]

The paper presents a practical implementation of hybrid simulation using Real Time Finite Element Method (RTFEM). Hybrid simulation is a technique for investigating dynamic material and structural properties of mechanical systems by performing numerical analysis and experiment at the same time. It applies to mechanical systems with elements too difficult or impossible to model numerically. These elements are tested experimentally, while the rest of the system is simulated numerically. Data between the experiment and numerical simulation are exchanged in real time. Authors use Finite Element Method to perform the numerical simulation. The following paper presents the general algorithm for hybrid simulation using RTFEM and possible improvements of the algorithm for computation time reduction developed by the authors. The paper focuses on practical implementation of presented methods, which involves testing of a mountain bicycle frame, where the shock absorber is tested experimentally while the rest of the frame is simulated numerically. [ABSTRACT FROM AUTHOR]

The paper deals with numerical analysis of the DCB test configuration together with the data reduction scheme described in the ASTM D 5528 Standard for determination of the mode I fracture toughness in case of the laminated composites with mechanical couplings. Numerical analysis based on the FEM approach was performed with the Abaqus software exploiting the VCCT technique. The experiments on the DCB beams made of coupled laminates were also performed. The results show, that the distribution of the Strain Energy Release Rate can be asymmetric. A need for appropriate data reduction schemes has been revealed. [ABSTRACT FROM AUTHOR]

The paper considers the problem of coach occupant safety during crash events. The authors present a simple low-cost seat buffer concept which may mitigate the effects of frontal impact. The method of computer simulation was chosen to solve the problem efficiently. The Finite Element Method (FEM) implemented in the LS-DYNA commercial code was used. The testing procedure was based on European Commission regulations, under which vehicles move at a defined speed. Simulations have shown that seat occupants suffer serious trauma during a crash, with the head experiencing relatively high acceleration, thus resulting in an HIC36 of 1490. The installation of a protective buffer mounted on the upper part of the seat reduced the HIC36 to only 510. However, in its current form it does not meet the requirements of the regulations. Further modifications to the overlay shape and structure are essential in order to better improve the deceleration of passengers' bodies. Moreover, a detailed model of seats and their anchorage should be taken into account. A more flexible structure should provide more positive and more accurate results. [ABSTRACT FROM AUTHOR]

We present an enhancement of the multiscale finite element method (MsFEM) by combining it with the hp-adaptive FEM. Such a discretization-based homogenization technique is a versatile tool for modeling heterogeneous materials with fast oscillating elasticity coefficients. No assumption on periodicity of the domain is required. In order to avoid direct, so-called overkill mesh computations, a coarse mesh with effective stiffness matrices is used and special shape functions are constructed to account for the local heterogeneities at the micro resolution. The automatic adaptivity (hp-type at the macro resolution and h-type at the micro resolution) increases efficiency of computation. In this paper details of the modified MsFEM are presented and a numerical test performed on a Fichera corner domain is presented in order to validate the proposed approach. [ABSTRACT FROM AUTHOR]

The paper presents the mixed-mode delamination of plates made of sublaminates. To this purpose an opening load mode of delamination is proposed as failure model. The failure model is implemented in ANSYS code to calculate the mixed-mode delamination response as energy release rate. The analysis is based on interface techniques. Within the interface finite element modeling there are calculated the individual components of damage parameters as spring reaction forces, relative displacements and energy release rates along the lamination front. [ABSTRACT FROM AUTHOR]

Many soft robotic structures are developed using soft fluidic actuators, which are developed using elastomeric materials such as silicon rubber. Due to the complicated geometries and nonlinearity in the soft actuator's design, it becomes very difficult to predict their behavior analytically. Finite Element Method (FEM) analysis is a numerical technique which is utilized to predict the stress, strain, and deformation in such actuators design. In this paper, bending behavior of two soft pneumatic fingers with varying wall thickness are designed and compared. Bending angle configurations of the designed fingers are evaluated at 30 and 40 kPa of actuating pressure. The obtained results show that to achieve a bending angle of 116 degrees, finger 2 requires 40 kPa of actuating pressure whereas finger 1 requires 80 kPa. Due to low stiffness of finger 2 as compared to the finger 1, which is resulted due to thickness variation in the two designed fingers, much higher bending angle configuration can be achieved at very low pressure for the finger 2. [ABSTRACT FROM AUTHOR]

In the present paper, different numerical analyses are carried out for modelling impact events. Smooth Particle Hydrodynamics (SPH) formulations, Finite Element Method (FEM) and a coupled FEM-SPH models are performed to investigate the response of AA5083-H116 Aluminium plate subjected to low velocity impact (12.31 m/s). Dimensions of Aluminium plate is 300 x 300 x 5 mm. There are 16 types of SPH formulation are available in Ls-Dyna, however, 4 of them are recommended to use with solid structures which are Standard SPH formulation (FORM=0), Renormalized SPH formulation (FORM=1), Total Lagrangian Formulation (FORM=7) and Renormalized Total Lagrangian Formulations (FORM=8). For FEM-SPH modelling, SPH particles are modelled with renormalized SPH formulations. Johnson-Cook material model is used with Gruneisen Equation of State (EOS) for the Aluminium plate. The response to impact event of models contain maximum deflection which is validated by experimental data available in literature. The results show, Total Lagrangian behaviour and FEM-SPH coupling have good agreement with experimental data by less than 2% error. However, maximum deflection value of standard SPH formulations obtained has 18.07% error. [ABSTRACT FROM AUTHOR]

The paper deals with the interaction of reinforced concrete slab with subsoil. The subject of the paper was the processing of nonlinear analysis of the performed experiment. The specifics of the solved task include that it connects the design of concrete structures and geotechnical tasks. It was necessary to take into account the actual behavior of the concrete structure and subsoil. The experiment includes a reinforced concrete slab by dimensions 2000 x 2000 mm, 150 mm thickness. Reinforcement was used netting steel bar ⊘ 8 / 100 mm. For the research task is important, that due to cracking in the reinforced concrete slab, its stiffness bending changes. This change affects the life of the structure due to its degradation. The paper focuses on the comparison of the experiment with the numerical model in two selected load cases. For numerical modeling was used the deformation variant of the finite element method and the 30 computational model. In the computational model, the fracture-plastic material model was chosen for concrete. The Newton-Rapson method was chosen for nonlinear calculation. [ABSTRACT FROM AUTHOR]

The numerical analysis of thermal damage process proceeding in biological tissue, containing blood vessel, during laser irradiation is presented. Heat transfer in the tissue is assumed to be transient and two-dimensional with perfusion coefficient dependent on tissue injury. The internal heat source resulting from the laser irradiation based on the solution of diffusion equation is taken into account. At the stage of numerical computations the boundary element method and the finite difference method have been used. In the final part of the paper the results obtained are shown. [ABSTRACT FROM AUTHOR]

Large pneumatic structures of deploying space reflector are highly efficient and significantly advantageous due to the following reasons: significant coverage at low material usage and deployment simplicity. At the same time experimental modeling of such structures is time-consuming and costly. So, numerical analysis of such structures is very important in preliminary design. This paper presents the mathematical problem statement of stress-strain state of pneumatic structures, as well as the modal analysis results for two pneumatic reflectors of 50 and 100 meters in size applying such materials as Kevlar and thin polyamide films. The above described problems were solved by well-known nonlinear finite element method. [ABSTRACT FROM AUTHOR]

The paper is devoted to three-point bending of an I-beam with include of transvers shear effect. Numerical calculations were conducted independently with the use of the Solid Works system and the multi-purpose software package ANSYS The results of FEM study conducted with the use of two systems were compared and presented in tables and figures. [ABSTRACT FROM AUTHOR]

This paper is devoted to a numerical approach of the stress and displacement calculation of a system made up of dental implant, ceramic crown and surrounding bone. This is the simulation of a clinical situation involving both biological - the bone tissue, and non-biological - the implant and the crown, materials. On the other hand this problem deals with quite 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. The authors proposed a three-dimensional numerical model to assess the biomechanical behaviour of this complex structure in order to evaluate its stability by determining the This paper is devoted to a numerical approach of the stress and displacement calculation of a system made up of dental implant, ceramic crown and surrounding bone. This is the simulation of a clinical situation involving both biological - the bone tissue, and non-biological - the implant and the crown, materials. On the other hand this problem deals with quite 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. The authors proposed a three-dimensional numerical model to assess the biomechanical behaviour of this complex structure in order to evaluate its stability by determining the risk zones. A comparison between this numerical analysis and clinical cases is performed and a good agreement is obtained. [ABSTRACT FROM AUTHOR]

In the paper we introduce Rν–generalized solution to the Stokes problem with singularity in a non-convex polygonal domain with one reentrant corner on its boundary. The weighted analogue of the LBB condition is proved. A new weighted finite element method is constructed. Results of numerical experiments have shown the efficiency of the method [ABSTRACT FROM AUTHOR]

This paper deals with the development and approbation of a computational model of damage accumulation in a vertical steel tank at the non-uniform foundation subsidence. The object of research is structure behavior at the survivability stage, namely, the character and sequence of damage initiation and accumulation (elastic-plastic strain, bottom and wall buckling) in the tank structure. [ABSTRACT FROM AUTHOR]

The paper deals with finite beam element with piezoelectric layers and functionally graded material of core. In the process of homogenization of FGM core and piezoelectric layers direct integration method and multilayer method is used. There is also presented the derivation of individual submatrices of local stiffness and mass matrix, where concept of transfer constants is used. [ABSTRACT FROM AUTHOR]

The paper summarizes the results of the development of fibre reinforced concrete intended for explosion resistant applications. Blast resistance of slurry infiltrated fibre concrete (SIFCON) with different amount and shape of fibres was investigated both experimentally and numerically. Test specimens with 2 types of steel fibres with different shape parameters in four volume fractions (2.5;5;7.5 and 10.0 vol.%) were investigated. Quasistatic mechanical properties have been determined and real blast test on the selected slab specimens were performed. The Finite Element (FE) method was used to predict the response of the slabs upon blast impact. New approach based on creation of the automatic scripts designed for generating of the FE network of fibre elements has been proposed and used. This approach enables creation of the FE model with various shape types and amounts of fibres. Calculations were performed in LS-Dyna solver. Using this concept, good agreement was concluded between the results of the real blast experiments and numerical simulations of slab specimens. The material characteristics and explosion test data have been used for numerical investigation, which defined the optimal wall composition and dimensions of the concrete element which should resist the explosion defined by type, size, weight and placement of the blast. [ABSTRACT FROM AUTHOR]

Based on experimental tests recently performed, this paper presents a numerical investigation on Steel Plate Shear Walls (SPSWs) in order to examine the influence of the tightening torque to be assigned to bolted connections between the plate and the boundary frame members on their seismic response. In fact, in SPSWs slippage in the bolted connections and plate yielding adjacent to the boundary members decrease the system stiffness more than that detected with welded connections. For this reason, the experimental cyclic tests performed at the Urmia University on one full and two perforated (with two different circular opening ratios) panels have been assumed as reference for setup of a numerical FEM model implemented through the ABAQUS finite element software. Numerical non-linear static analyses by varying the values of tightening torques used in the bolted joints between the panels and the frame members have been performed to achieve the pushover curves able to approximate the skeleton curves of experimental cyclic tests. The experimental-numerical comparisons have shown an excellent agreement in terms of both initial stiffness and maximum lateral strength. The gotten encouraging results allow to consider the variation of the tightening torque in bolted connections as a promising solution for improving the initial stiffness and shear capacity of SPSWs. [ABSTRACT FROM AUTHOR]

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 cases A comparison between this numerical analysis and clinical cases is performed and a good agreement is obtained. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to describe the parallelization of PragTic - a fatigue damage simulator. There is a discussion about the former version inefficiency (caused by frequent I/O operations), parallel implementation and parallelized PragTic scalability testing. The parallelization is done at the node level where the nodes are defined in the context of the finite element mesh. We also ran a simple model example (hundreds of nodes), real world example (millions of nodes) and our approach is to test using numerical experiments where we achieve weak parallel scalability. At the end of the article, the results of numerical experiments are depicted in tables and graphs. [ABSTRACT FROM AUTHOR]

Numerical code coupling is a procedure that allows the solution of multiphysics and multiscale problems. In the present paper we perform a numerical code coupling between the in-house FEM code FEMuS and OpenFOAM. The MED format that come with the SALOME platform is used to exchange data between the two different codes. The test case consists of a squared cavity where the fluid flow is driven by a buoyant force. The momentum and energy equations are solved by both numerical codes. In the coupled case, the temperature field obtained from the FEM solution is used to calculate the buoyancy term of the OpenFOAM momentum balance equation. We investigate the case with low Rayleigh number and report results for both the coupled and uncoupled cases, examining the influences of different domain discretizations. [ABSTRACT FROM AUTHOR]

The modeling method and key technologies of the automobile frontal crash simplified parametric finite element model is studied in this paper. By establishing the auto body topological structure, extracting and parameterizing the stiffness properties of substructures, choosing appropriate material models for substructures, the simplified parametric FE model of M6 car is built. The comparison of the results indicates that the simplified parametric FE model can accurately calculate the automobile crash responses and the deformation of the key substructures, and the simulation time is reduced from 6 hours to 2 minutes. [ABSTRACT FROM AUTHOR]

The paper discusses the concept of a system that encapsulates the transition from geometry building to strength tests. The solution we propose views the engineer as a programmer who is capable of coding the procedure for working with the modeli.e., to outline the necessary transformations and create cases for boundary conditions. We propose a prototype of such system. In our work, we used: Python programming language to create the program; Jupyter framework to create a single workspace visualization; pythonOCC library to implement CAD; FeniCS library to implement FEM; GMSH and VTK utilities. The prototype is launched on a platform which is a dynamically expandable multi-tenant cloud service providing users with all computing resources on demand. However, the system may be deployed locally for prototyping or work that does not involve resource-intensive computing. To make it possible, we used containerization, isolating the system in a Docker container. [ABSTRACT FROM AUTHOR]

Fire resistance of different structural members is an important issue of their strength and durability. A simple but effective tool to investigate multi-span reinforced concrete beams exposed to fire is discussed in the paper. Assumptions and simplifications of the theory as well as numerical aspects are briefly reviewed. Two steps of nonlinear finite element analysis and two levels of observation are distinguished. The first step is the solution of transient heat transfer problem in representative two-dimensional reinforced concrete cross-section of a beam. The second part is a nonlinear mechanical analysis of the whole beam. All spans are uniformly loaded, but an additional time-dependent thermal load due to fire acts on selected ones. Global changes of curvature and bending moment functions induce deterioration of the stiffness. Benchmarks are shown to confirm the correctness of the model. [ABSTRACT FROM AUTHOR]

Nowadays the design of single process steps and even of whole process chains is realized by the use of numerical simulation, in particular finite element (FE) based methods. A detailed numerical simulation of hot forging processes requires realistic models, which consider the relevant material-specific parameters to characterize the material behavior, the surface phenomena, the dies as well as models for the machine kinematic. This data exists partial for several materials, but general information on steel groups depending on alloying elements are not available. In order to generate the scientific input data regarding to material modelling, it is necessary to take into account the mathematical functions for deformation behavior as well as recrystallization kinetic, which depends alloying elements, initial microstructure and reheating mode. Besides the material flow characterization, a detailed description of surface changes caused by oxide scale is gaining in importance, as these phenomena affect the material flow and the component quality. Experiments to investigate the influence of only one chemical element on the oxide scale kinetic and the inner structure at high temperatures are still not available. Most data concerning these characteristics is provided for the steel grade C45, so this steel will be used as basis for the tests. In order to identify the effect of the carbon content on the material and oxidation behavior, the steel grades C15 and C60 will be investigated. This paper gives first approaches with regard to the influence of the carbon content on the oxide scale kinetic and the flow stresses combined with the initial microstructure. [ABSTRACT FROM AUTHOR]

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 discusses on chapter methodology are the method used to analysis the strength when the load applied to the structure. The software used to analysis the structure is Finite Element Method from CATIA V5R21 software. Bending test is done on the jointing part between the edges of the hexagonal shape by using Universal Tensile Machine (UTM). The data obtained have been calculate by bending test formulae and sketch the graph between flexural strains versus flexural stress. The material selection of the furniture is focused on wood. There are three different types of wood such as balsa, pine and oak, while the properties of jointing also be mentioned in this thesis. Hence, the design structural for honeycomb shape already have in the market but this design has main objective which has a good strength that can withstand maximum load and offers more potentials in the form of furniture. [ABSTRACT FROM AUTHOR]

This paper outlines a framework for evaluating the asymptotic crack tip field solution incorporating Tz parameter in three-dimensional crack problems. Assessment was done based on the comparisons with analytical solutions and results from three-dimensional crack-tip finite element analysis. Fully plastic asymptotic crack tip stress field solutions were provided by carrying out detailed full field finite element analysis on single edge deeply cracked bar subjected to bending load based on a non-hardening material response. Two out-of-plane specimen thicknesses were considered for the bar to evaluate the effect of out-of-plane constraint on the distribution of crack tip stress field. The asymptotic solutions of thick bend bars were found to be contained within a Prandtl crack tip field at the center of the specimen. At the free surface of the specimen, a corner field develops, causing deviation of the J-Q-Tz solution from the three-dimensional surface crack-tip field. The results also showed that the three dimensional asymptotic crack tip solution, J-Q-Tz has limited capabilities in characterizing the crack tip fields for thin specimen. [ABSTRACT FROM AUTHOR]

In this paper, the investigation of in-plane constraint loss in a semi-elliptical surface cracked panel(SCP) specimen based on a detailed non-hardening finite element analysis with aspect ratios a/c of 0.5 and relative depths a/t of 0.33 and 0.5 under bending loads. The asymptotic stress field solutions were compared to the fully constrained Prandtl field for the plane-strain case and Sham & Hancock crack tip plane-stress fields. The asymptotic solutions of the semi-elliptical shallow and the deep cracked bars were found to be contained within a Prandtl crack tip field at the centre of the specimen. Loss of constraint was observed at the free surface of the semi-elliptical surface crack. [ABSTRACT FROM AUTHOR]

In this paper heat transfer and fluid flow in a two-dimensional lid-driven square cavity with discrete source-sink is studied. A finite element method is used for solving the governing equations. The parametric studies are Darcy number in the range of 10-5 to 10-1, Grashof number in the range of 10³ to 105, Reynolds number constant at 100 and Prandtl number constant at 0.71. Galerkin weighted residual method is used to perform numerical solutions. The streamlines, isotherms, average Nusselt number, and average temperature of the fluid in the enclosure are presented for the dimensionless parameters. It is found that the heat transfer rate is decreased for decreasing of Darcy number. [ABSTRACT FROM AUTHOR]

The paper deals with modelling and analysis of architectural heritage through the discussion of an illustrative case study: the Medieval Sanctuary of Sant'Agostino (Offida, Italy). Using the finite element technique, a 3D numerical model of the sanctuary is built, and then used to identify the main sources of the damages. The work shows that advanced numerical analyses could offer significant information for the understanding of the causes of existing damage and, more generally, on the seismic vulnerability. [ABSTRACT FROM AUTHOR]

In the present paper, Thomason's criterion is coupled with the well-known Gurson-Tvergaard-Needleman (GTN) damage model and used for the determination of the critical void volume fraction ƒc, which marks the initiation of the coalescence stage. The onset of void coalescence predicted by Thomason's criterion is compared to that obtained by using a predefined ƒc, which is usually fitted on the basis of experimental results, as originally proposed in the GTN model. Comparisons are made in terms of both single finite element simulations and numerical results of deep drawing of a cup. [ABSTRACT FROM AUTHOR]

This paper presents numerical study of the seismic behavior of reinforced concrete beam to concrete filled steel tube column connections with ring-beam. The material stress-strain relations, element type and boundary condition are selected, which are consistent with actual situation. Then the seismic behavior of this type of joint are researched by ABAQUS, and finite element analyses are conducted under cyclic loading. Its parameters are discussed including thickness of steel tubular column wall, sectional dimension of the ring-beam and strength of the core concrete . The results show that the ultimate capacity of the connections is improved with sectional dimension of the ring-beam increased. In the meanwhile, the influence on skeleton curve of the joints is slight of which included thickness of steel tubular column wall and strength of the core concrete. [ABSTRACT FROM AUTHOR]

In this paper, we consider the two-dimensional elasticity problem with a singularity caused by the presence of a reentrant corner on the domain boundary. For this problem, the notion of the Rv-generalized solution is introduced. On basis of the Rv-generalized solution we construct a scheme of the weighted finite-element method (FEM). The proposed method provides a first-order convergence of the approximate solution to the exact one with respect to the mesh step in the 1 W12,v (Ω)-norm. The convergence rate does not depend on the size of the angle and kind of the boundary conditions imposed on its sides. This statement is illustrated by the results of numerical experiments. [ABSTRACT FROM AUTHOR]

Guided waves are well suited for structural interrogation of continuously welded rail track, and are being exploited in a commercial monitoring system. This system relies on a pitch-catch mode of operation to reliably detect complete breaks in the rail. Efforts to extend this system to include a pulse-echo capability (for detecting damage before complete breaks occur) require numerical modelling to predict how propagating waves interact with damage. To this end, an efficient hybrid SAFE-FE numerical method, capable of predicting reflections from arbitrary discontinuities, has previously been implemented. In this paper, we attempt to validate the SAFE-FE method by comparison with both numerical and experimental results. A numerical comparison between the SAFE-FE method and a time domain analysis using the commercial finite element package ABAQUS Explicit is performed for two example problems. The ABAQUS Explicit time domain results are processed so that a comparison of power reflection coefficients is performed. In both instances, good agreement between the hybrid method and ABAQUS Explicit were observed. The experimental comparison involved the measurement of reflections from passive reflectors bonded to a rail in the field. These measurements were used to estimate the power transmission and reflection coefficients of the reflectors. A reasonable correlation was achieved for the power reflection coefficients, but the hybrid method was shown to somewhat over-predict the power transmission coefficients. [ABSTRACT FROM AUTHOR]

In this paper, the static response of three-dimensional beams made of functionally graded materials is investigated through a family of hierarchical one-dimensional finite elements. A wide variety of elements is proposed differing by the kinematic formulation and the number of nodes per elements along the beam axis. Elements' stiffness matrix and load vector are derived in a unified nuclear form that does not depend upon the a priori expansion order over the cross-section nor the finite element approximation along the beam axis. Results are validated towards three-dimensional finite element models as well as equivalent Navier-type analytical solutions. The numerical investigations show that accurate and efficient solutions (when compared with full three-dimensional FEM solutions) can be obtained by the proposed family of hierarchical one-dimensional elements' family. [ABSTRACT FROM AUTHOR]