Search

A device has been designed to measure the whole stiffness which is behalf of paper plate’s carrying capacity. When the device was working, one end of the paper plate was hold as a hand did, the other end of the paper plate was pushed to 15°angle from the horizontal surface, and the force on the paper plate was recorded. Comparing load-bearing performance, the whole stiffness is more accurate to reveal the differences of the paper plates.

Variable head sizes of paper roll will influence the stability of paper feeding device and hence the printing quality. Therefore, it is necessary to improve the printing quality by improving the stability of paper feeding device based on dynamic analysis on the phenomenon of variable head sizes of paper roll. It is found through dynamic analysis that the effect of variable head sizes on the support force of bearings is nearly five times that of the case when such effect does not exist. Vibration performance analysis of paper feeding device using finite element analysis obtains the natural frequencies of the first 6 orders for paper carriage and their dominant vibrational modes. This provides theoretical basis for the improvement of paper feeding device.

The paper honeycomb is a strain-rate-sensitive material. It is significant to predict the mechanical properties of paper hoenycomb at different strain rate for optimizing packaging design. According to the Cowper-Symonds equation, the influence of the strain rate on the paper honeycomb was studied, and the characterization parameters were found by parameter fitting. It provides a reference for optimizing design of paper honeycomb.

The aim of this paper is to present a finite element method to predict buckling characteristics of paper honeycomb sandwich panels with composite skins under dynamic axial compression via ANSYS/LS-DYNA. First of all, some problems of the conventional method using honeycomb plate theory, sandwich laminboard theory and equivalent panel theory were pointed out. In order to develop an effective predicting method, by assuming appropriate periodic boundary condition on the edges, a simplified finite element model on hexagonal structure of a unit cell for sandwich panels was developed utilizing the 3D finite element method. The effective Young's modulus of the cellular wall was obtained from the result of the test on the honeycomb core. Several useful conclusions are drawn about the axial crushing of honeycomb sandwich composites and unit cell and can be used to guide the design of composite structures. The paper further attempts to explain numerical results are well consistent with the corresponding experimental ones.

lightweight composite paper honeycomb core wallboard as green building materials and low carbon product of modern life, its lightweight and energy saving, environmental protection, easy construction which other wallboards can't reach, but in actual use, the residents reflects its sound insulation performance is not very well, The lightweight composite paper honeycomb core wallboardand is composite with two rigid panel and paper honeycomb core which is in the middle of the wallboard. However, at present, people rarely Study on Sound Insulation Property of lightweight composite paper honeycomb core wallboard, so take the lightweight composite paper honeycomb core wallboard as the research object, through several sets of Different Specifications wallboard of experiment test,, the results showed that:The sound isolation property of calcium silicate panel is better than Gesso panel’s. The thick panel’s sound isolation property is better than the thin one. At the same thickness, the more layers of paper honeycomb core, the better sound isolation effect. Increase the layer number of paper honeycomb core has remarkable effect on sound isolation property.

To prove the indentation quality of packaging products, the indentation depth and the bottom die width were changed to study the effect of the indentation on the indentation quality and make sure the best indentation depth with HANATEK indentation tester for 20kinds of paper. The relationship between the performance of paper and the best indentation depth is analyzed by the method of linear regression. The result shows that the deeper the indentation depth is, the bigger the folding angle is. The folding angle of steel wire and paper fibers in parallel rows is bigger than that in vertical rows. The deflection and longitudinal tensile strength of paper have notable effect on the indentation depth, transverse tensile strength and tightness are poor and the folding endurance has no remarkable influence.Printing packing profession in our country has made significant progress with the rapid growth of economy and the rapid expansion of international trade. The postpress technology plays a key role to the quality of printing packing and the die cutting indentation is the important technique of production. The die cutting indentation makes the print artistic and suitable , it suits all kinds of print surface finishing process and is widely applied in book cover, trademark, label, as well as carton. So how the quality of the die cutting indentation has directly effect on the market image. However, the indentation processing basically depends on the experience of technical staff in the factory at present. To study the relationship between the performance of paper and the indentation condition can provide certain scientific basis for the choice of indentation process.

The precision of transferring paper is key factors to decide the print overprint accuracy, and vibration has an important impact on paper transferring accuracy. Empirical mode decomposition (EMD) can be used to extract the features of vibration test signal. According to the intrinsic mode function (IMF) by extracted, it is useful to analyze the dynamic characteristics of swing gripper arm on motion state. Due to the actual conditions of printing, the vibration signal of Paper-Transferring mechanism system is complex quasi periodic signals. Hilbert-Huang marginal spectrum that is based on empirical mode decomposition can solve the problem which is modals leakage by FFT calculated in frequency domain. Through the experimental research, the phase information of impact load at the moment of grippers opening or closing, which can be used for the optimization design of Paper-Transferring system and the improvement in the accuracy of swing gripper arm.

Bending resistance of single honeycomb paper-core under axial dynamic load has been analyzed to meet the need of honeycomb paperboard produce. First, the models were built after buckling theory analysis. Dynamic characteristics of compressive process were analyzed in the FEA software. It was indicated that: When the height of model was lower than a certain value, the process was divided into four parts: linear elastic phase, elastic-plasticity phase, plasticity collapse phase and densification phase. However, when the height of model was above than the certain value, the model was easy to bend in the intermediate region. Some results such as force and shearing stress had been gotten. At last, the compressive process was verified by experiment, which was bigger value due to air and glue water existed in honeycomb core.

To improve the stability of a Paper-Transferring Mechanism (PTM), a profound understanding must be made on its vibration characteristics, on which based, a modified design was made. Through kinetic and dynamic analysis of the PTM, the natural frequencies were obtained based on the vibration signal detection and noise signal analysis. To reduce the vibration response of the PTM, first is to reduce its maximum acceleration and reduce the quality of moving parts and improve its quality distribution, then structural modification to the wallboards and pull beams of the platform should be made to render its inherent frequencies from its working frequencies.

When processing in the manufacture for production of paperboard boxes, there arises amount of waste paper as material, which is subsequently sent for recycling. The paper passes through the first crushing device, which ensures small pieces so that they can be transported by pipeline to a pressing apparatus. Paper material in the molding machine is forced into the pits of suitable size due to the additional handling and transport. So both pipe as well as the molding machine may be so congested with material during the failure that the equipment requires unexpected additional cleaning. The sensor detects the level of waste material in pressing device, thereby avoiding congestion in a timely manner and prevents subsequent failure. The sensor uses the resonant frequency of the oscillating rod. The microprocessor controls and evaluates the response of the rod oscillations. Sensor performance was exposed to qualification tests when it shows ability to operate also in extreme conditions such as dirty and dusty surrounding with high humidity and temperature level. Sensor detects the vibration attenuation at the poles of the rod that is caused by touching different materials. Thus may indicate changing concentration level of a material and not just pieces of paper but for example, also sand or other suitable materials or height of fluid surface.

Ground Penetrating Radar is a method using high frequency impulse electromagnetic wave to detect underground media distribution. It has been gradually widely used as it has the advantage of high accuracy, fast and nondestructive respecting to the conventional method such as visual measurement and confirmation with drilling hole. In the tunnel construction process, it is easy occurred that the quality problem of insufficient lining thickness, the distance of steel arch centering too large and the concrete disengaging. The work achieved in this paper based on the project of LongSheng tunnel and its conclusion and suggestion has important practical engineering significance.

The complex nonlinear problem exists between the factors which influence the strength of hybrid fiber reinforced concrete. The nonlinear relationship between input variables as the factors and output variables as the strength can be obtained artificial neural network which have the feature of self-adapting, self-studying and nonlinear mapping. RBF and BP neural network models are established in MATLAB in this paper based on experimental values. Compressive strength and flexural strength of hybrid fiber reinforced concrete are predicted respectively and comparing with the measured values, predicted values are analyzed. The results show that the predicted values based on RBF tally with the experimental values, and the strength prediction ability of RBF is higher than BP neural network. The needs of engineering can be meet by this method with accurate prediction ability, a new method for the study of hybrid fiber reinforced concrete strength is provided.

In order to solve the problem of multi-index amalgamation on the reliability evaluation for tunnel lining with cracks, this paper based on extension theory, use matter element model theory to establish the matter element of the reliability evaluation for tunnel lining with cracks, use the dependent function to establish the relevance between matter element and reliability grade, combine the research result of the Beiru tunnel lining cracks disease to evaluate the reliability. The results show that it could consider the multi-index of the cracks to use the extension theory to evaluate the reliability of the tunnel lining with cracks, and the evaluation results are more scientific and reasonable. It is viable to use the dimensionless parameters to represent the crack geometry. In the K6, the treatment scheme is mechanical reinforcement. In the K2 and K3,the treatment scheme is surface sealing. The reliability evaluation results supply theory basis and technical guidance for the tunnel long-term health service and the disease treatment.

Brackets is the ancient Chinese wooden building unique ways and one of the main features of the structure. Its dual function of both structural and architectural: An important component of both the structure itself, because of its flexible features tenon, the dynamic response of the structure can absorb greater energy, play a good role in the earthquake; But it is also a special architectural ornament, can play the effect of beautifying buildings. Therefore, this paper based on the finite element software ABAQUS brackets by the force of the mechanism of failure modes and numerical simulation analysis for the brackets and the whole structure of the wood to provide a scientific assessment and reinforcement.

The spiral shaft parts have been widely applied in machinery and equipment manufacturing industry, the paper based on DEFORM-3D, the rigid-plastic finite element model of cross wedge rolled spiral shaft parts was established. The rolling process was simulated, the strain laws were analyzed, and the characteristics of metal flow were explored. From which we can find Plate cross wedge rolled spiral shaft parts is completely feasible. The results provide the theoretic basis for precision deformation of cross wedge rolled spiral shaft parts.

This essay analyses the mechanical behavior of the paper machine drying section rack by FEA method, obtaining transformation and stress distribution of the rack under static loading, so as to achieve the natural frequency and the corresponding strain, stress of the rack. This paper could provide theoretical foundation for design, fault diagnosis or reforming speed acceleration.

Pollen can go into human body with breathing. According to this fact, we use air-attracting to fabric for simulating breathing as test method. A black paper with same size is put behind the fabric. Pollen can go through fabric onto the paper by air-attracting. According to the change of paper quality before and after air-attracting, we can calculate the percentage of pollen quality change through fabric. And this value can represent the anti-pollen performance of fabrics.

Maximum distribution of hydrodynamic pressure on the flume sidewall were studied in this paper based on the finite element method. It contains the difference comparison of theoretical and numerical formulas, rules of maximum hydrodynamic pressure distribution under regular and irregular incentives, and hydrodynamic pressure changes with different height of bracket below the aqueduct. Studies show that: In the 30m height range, with the rise of bracket, the hydrodynamic pressure grows linearly.

Wood is a renewable source of structural material with high relative strength/weight, low energy production, which kidnaps and stores carbon in its production. The large use of wood is due to its special qualities as raw material for other products manufactured in residential construction or major works such as bridges, has been widely used in roofing for industrial and commercial buildings. Commercially there are limitations on the length of the wood, resulting from the extraction of tree trunks, thus requiring the adoption of binding elements is the use of self-tapping screws efforts required by side and which can be axial, shear, tensile or compression. Whereas in Brazil does not yet exist and the promising future of the product, this research aims to study the behavior of self-tapping screws together with Brazilian reforestation species ofPinusoocarpaandLyptus(softwood and hardwood). Rothoblaas self-tapping screws had a good penetration in both woods without requiring pre-drilling, the species of Lyptus wood showed the highest values of strength and the inclination of the screws, at 45 degrees showed the best results on either species of wood.

As abrupt change of the shape and elastic constant in the weld area occurs to the welding joint, there will be obvious stress concentration near the weld area when being loaded. Lifting and Lowering Method and Grouping Method prevailing in the world are applied to conduct an experiment about fatigue strength of a certain welding joint in Wuhan Iron and Steel and S-N curve is drawn in this paper based on the condition of nominal stress. In addition, the influence of weld size of the welding joint on the distribution of stress is studied through the calculation of finite element numeral value and experimental test. According to the factor of stress concentration, S-N curve is modified to provide the data support for the application of the welding joint and assessment of fatigue strength.

In asphalt pavement maintenance design the deflection of pavement strength and the drilling core examination of damage on each structure layer are required. This paper based on the advanced technology of the FWD and developed a link with the Benkelman Beam testing. It indicated that assessment of the usage information on each structure layer by using the Modulus Back Calculation was well matched with the core results; therefore, it improved the work efficiency to a new level.

To improve the calculation precision of deformation in prestressed concrete bridge in passenger dedicated line and accurately predict the development of shrinkage and creep in bridge, a universal applicable modified model was put forward in this paper based on ACI 209R(1992) shrinkage and creep model. In the modified model, three influence factors-slump, strength and reinforcement - are corrected. And the modified model results were compared with the experimental results. It shows that the modified model can more accurately predict the development of shrinkage and creep of high-speed railway bridge and better accord with the law of it.

Springback is the prominent problem in bending forming of sheet metal, which is difficult to control accurately, especially for the complex shaped bending parts. The change of friction conditions will cause significant changes of bending springback amount. The theoretical analytical model of quadrangle parts bending, which takes into account of the harden ability, anisotropy and elastic deformation of material, is proposed in this paper based on the plane deformation assumption and the bending theory of sheet metal, the quadrangle parts bending of wide sheet is analyzed theoretically, the approximate calculation relational expression is derived between friction coefficient and springback angle, and the influence of friction on springback is discussed. In the same conditions, the springback result deduced from theoretical formula is basically consistent with numerical simulation and experiment result.

Springback compensation of Multi-point forming (MPF) was analyzed in the paper based on the ideal elastic-plasticity and linear hardening material models. The calculation formulas for adjusting radius of MPF die, both single-curvature and double-curvature, were obtained. Cylinder and spherical surfaces were formed by MPF equipment. Experimental results show that the errors between formed surface and target shape are within 5%. Moreover, when using formulas derived from linear hardening model, it is found that the formed surface is more close to target contour, and the presented formula can be used to determine the adjusting radius of MPF die in practice.

The isogeometric formulation seems to be advantageous especially when it comes to curved geometries such as curved beams and shells. In this paper, the NURBS isogeometric formulation of beam element is presented. The same basis functions are used for both geometry description and unknown approximations so there is no accuracy loss caused by a geometry approximation. The element is based on Timoshenko beam theory which enables the use of the element for both thick and thin beams, nevertheless in case of thin beams the shear-locking phenomena is observed. In the paper it is shown that the reduced integration is insufficient for locking removal and capability of Discrete Shear Gap (DSG) method to unlock the elements is examined. For clear demonstration of locking-removal techniques the implemented element is first tested for the case of straight beam, then the performance is demonstrated on the curved geometry.

The aging of hydraulic concrete structure is a highly complicated problem. To reasonably evaluate the aging situation of a long-term operating concrete sluice, the core samples are obtained by field sampling from the sluice piers and the mercury injection experiment is carried out in this paper. The main objectives of this experimental investigation are to analyze the pore structure characteristics of the different parts in core samples and discuss the concrete aging rule of hydraulic concrete structure. The experimental results show that the aging of the hydraulic concrete has a certain relationship with the evolution of the concrete pore structure. It is feasible to use the pore structure of concrete to express the concrete aging of the hydraulic structure. The research in this paper will provide a basis for further study on the aging mechanism of the hydraulic concrete structure.

In the paper there are presented experimental results concerning mechanical characteristics of friction-welded joints in comparison with electron beam welded joints, made by 20VNiMoCr120 heat-resistant steel, which are part of some elements working at high pressure and temperature. The paper represents a study which suggests non-conventional welding and heat-treatment procedures for water and steam-supply pipes, large cylindrical recipients with high values of wall thickness, boiler pipes, steam turbines which compose thermo-energetic installations, in order to prevent failure appearance. The actual level of development in all activity fields proves the fact that on top of the performance and modernism, technological products and processes must assure a high reliability. All the results and experimental researches are obtained by the first author in her PhD Thesis.

This paper reports the stress distribution inside the workpiece under ultrasonic vibration cutting (UVC) condition. Many researchers have reported the improvements of tool wear, burr generation and surface integrity by reduction of time-averaged cutting force under UVC condition. However general dynamometers have an insufficient frequency band to observe the ultrasonically varying processing phenomena induced by UVC. In this paper, stress distribution inside the workpiece was observed by combining the pulse laser as light source synchronized with ultrasonically vibrating cutting tool and the photoelastic method. The one shot of pulse laser with pulse width of 15nsec visualizes an instantaneous stress distribution. Sweeping the phase of emission against to ultrasonic oscillation, 360 frames for 35.7μs, one period of ultrasonic oscillation, are captured. Because UVC induced an intermittent cutting condition, the stress distribution changed periodically and disappeared when the tool leaved from the workpiece. The ideal chip-generating period is calculated by relative motion between tool and work. We found that the actual chip-generating period was extremely longer than ideal period.

The aim of the present paper is to establish the optimal parameter values of the cutting regime of a milling process. The paper presents a study regarding the influence of the cutting parameters on the surface roughness of the material and also on the vibration generated by their combinations, during a processing by milling. The studies are made on samples made from S355 JR steel with a metal milling machine FUS 25, which is used also for the experiments. The samples dimensions are 210x150x16mm. For the experiments there was used a cylindrical - frontal milling tool, with 32mm diameter and 10 tooth. Basic parameters of milling processing of materials we have considered in this paper are: feed rate [mm/min]; cutting speed RPM [rot/min]; depth of cut [mm]. For each of this parameters three levels were envisaged. For a 100% accurate experiment results at least 27 experiments must be done. Using an L9orthogonal array, the number of experiments is reduced to nine and the accurate of the method is around 99.96%. The optimal process parameters values are obtained using Taguchi method considering three situations. In the first case the goal is to get only a fine roughness for the sample. The second studied case is focused on finding a low level for the vibration generated during the milling process. The aim of the last study is to find a fine roughness and also a low level of vibration for the process. The analysis of variance (ANOVA) is applied, in all cases, in order to estimate the error variance and to rank the process parameters according to their importance.

The paper is about a research focused on a development of thin slabs made from white UHPC. These slabs are reinforced by scattered PVA fibres and textile glass reinforcement in form of 2D net. The aim of the experiment is the development of tin slabs that can be used as facade or roof panels. The course of the experimental tests of these slabs and its correspondence with the numeric analysis made with ATHENA software is in the paper. Three slab specimens with size of 750 x 125 x 15 mm were tested in four-point bending. The white UHPC matrix was reinforced by the scattered PVA fibres and the 2D textile glass reinforcement with mesh 20 x 20 mm. The used 2D reinforcement was coated against alkali conditions, so called AR - Glass with 2400 TEX fineness. The reinforcement was placed and fixed near the lower surface of the slabs. The course of the tests was continually monitored by an automatic measuring unit where especially the acting force, the deformation in the middle of the span, the deformation in the supports and the progressive formation and development of cracks were detected. The numeric model was created in 3D surroundings of Gid 2011 program and then converted into ATENA software.

The paper is focused on the use of advanced composite materials in the real application areas of buildings exposed to extreme environmental stress. The paper describe properties of composite rebar, especially with regards to long-term resistance to chemical and corrosion attack, minimization of heat transfer or resistance in construction with reduced concrete cover. The paper also presents behavior of composite rebar and concrete samples with composite reinforcement during loading and fire tests.

This paper refers to behaviour and capacity of axially loaded columns strengthened under load using welded steel plates. This method of strengthening is fast, simple and widely used but no universal and reliable analytical solution has been presented yet. In the paper, focus is put on flexural buckling. The approach using cross-section properties of strengthened member and the modified buckling reduction factor was used to calculate the ultimate resistance. In buckling theory, the resistance of column subjected to compression load is reached when the most stressed fibres start to yield. However, some researchers allow certain amount of yielding for base material of columns strengthened under load. In the paper, the new modified buckling reduction factor based on Eurocodes is derived. Two types of column strengthening under various preload magnitudes are investigated using finite element study in ANSYS code and transient analysis type. Birth and death of elements is used to simulate strengthening welded plates. The results are compared with analytical solutions.

This paper investigated the damage degree and damage mechanism of aluminum sandwich plate subjected to blast loading by using numerical simulation method. Finite elements models of aluminum foam sandwich plates were established. The distortion and damage pattern of the sandwich plate under different masses of detonator were got by using LS-DYNA to simulate the destructive effect of shock wave and detonation product against sandwich plate. The results showed that the maximal deflection and overloading of the sandwich plates were different because of the changing of mass of detonator. This paper could provide some reference for the designing of sandwich structures.

The paper addresses the issues of fire behavior of masonry walls made of traditional/historical component materials (bricks and mortar). There are reasons for coupling investigations on the residual mechanical properties to fire resistance data, aiming at a more complete knowledge of the behavior of a masonry member during and after fire exposure. The paper is part of a research that aims at investigating the relationship between fire and post-fire (i.e. residual) mechanical behavior of masonry walls, paying attention to scale-related problems and to the possible exploitation of numerical tools to establish simplified approaches. The goal is to establish relationships between fire resistance ratings under exposure and decay in mechanical properties after exposure; the parameter of wall thickness is especially investigated, by choosing four different values (i.e. 12, 25, 38 and 51 cm). This is performed by means of FEM analysis with DIANA 9.4.4 software, simulating a standard ISO 834 fire resistance test followed by a mechanical compressive failure test on each investigated type of wall. The approach, successfully tested against experimental data already available, features a preliminary transient heat flow analysis which gives a numerical prediction of fire resistance after violation of I (Insulation) criterion; then, a staggered heat flow - stress analysis repeats the heating of the wall up to insulation failure and calculates the thermal strain accounting for cracking; finally, a ‘cold’ structural analysis in compression is performed on the thermally-deformed model after cooling. The paper also addresses a way for the extended application of the research outcomes, relying on a simple approach based on the concept of equivalent fire severity.

The maximum values of normal and shear stresses are the basic parameters which influence directly the initiation and propagation of multiaxial fatigue cracks.Based on the above, the first part of the paper presents an analysis of principal stresses (normal and shear) in case of symmetrical tension-compression loadings with superimposed phase-shifted symmetrical torsion cycles. The influence of stress amplitude ratio and phase shift on the maximum (normal and shear) stresses and on the directions of the planes along which these act is analyzed and graphically represented using stress hodographs.The second part of the paper highlights the possibility of using the maximum value of the normal or shear stress as base parameter for durability studies under multiaxial fatigue, based on existing experimental data. The mentioned data is correlated with the results of an original experimental program carried out by the authors on 41Cr4 steel and conclusions are formulated with regard to the role of maximum shear stress in life-time calculation.

The bridge across the Hostovsky creek, on the expressway R1 on Slovakia was open to public traffic at autumn 2011. The bridge itself is measured since the time of erection. The authors of the presented paper are now preparing a new plate-element model, which shall contribute to the better prediction of the long-time behaviour. In this paper, the new model is presented and compared with the measurements from the static test of the bridge.

The paper deals with a system of precast floor plates from lightweight concrete intended mainly for building of family houses and residential construction. The developed system has two types of precast floor plates made from lightweight concrete: floor plates for floor systems and solid section floor plates. This paper describes solid section floor plates. The unambiguous advantage of lightweight concrete floor construction is weight lower by as much as 37% compared to floor structure made from common concrete, while bearing strength remains unchanged as well as high fire resistance. This type of floor slabs has also been successful in the system of assembled prefabricated houses thanks to its lower weight and elimination of the wet construction process.

Applications of precast elements made of UHPC have been increasing in recent years. Also in the Czech Republic, UHPC can be found as a structural material in first applications in both, buildings and transport structural engineering. Structures made from this modern material required experimental programs verification of material properties and also for determination of behaviour of structural elements. In previous research of the bond of UHPC and various types of reinforcement was proven to be very good, which makes it possible to reduce radically anchorage lengths. This paper deals in more detail with determination of the bond of prestressing strands and UHPC, during the first week after casting, in particular. For prestressing of precast elements, there are very important short-time strengths and short-time bond is showing to be a decisive factor for optimum prestressing time. Second part of the paper is focused on impact of thermal stress on bond of prestressing strands and UHPC. Samples were subjected to the cycling heat/frost and effect of a number of cycles on final bond behaviour of both UHPC and ordinary concrete were investigated. The article describes differences between ordinary concrete and UHPC.

Ionic Polymer Composite Material (IPMC) is a new type of smart material which has the capability of activation under the application of a small voltage. It is flexible; light weighed, produces high force and can be activated in any two opposite directions. These benefits have inspired the scientists and researchers to explore its availability for real-world applications in various fields. In this paper, the application of IPMC has been considered for the provision of required force to the movement of a grasshopper knee joint for the upward or stretching movement by the knee. In other words, it has been proposed to act as an artificial muscle for the mentioned job. Furthermore, simulation is carried out for two separate conditions of the weight ratios of the weight of the leg and that of the IPMC strip and simulation is carried out to clarify the relation between the force and deflection. The simulation is based on mathematical model that has been previously developed. Analysis of the simulation results of the two conditions indicated that more force is required to move a heavier leg by a certain amount of angle as compared to the force requirement for moving a lighter leg. This paper represents the simulation results for the upward movement of the link; however the same model and its simulation can be applied to that of the reverse direction because of the unanimity of the material properties and specifications.

To further improve the material utilization in cross wedge rolling, the paper simulated the forming of closed cross wedge rolling through DEFORM-3D, a rigid-plastic finite element analysis software, and analyzed the distribution and changing rule on the fields of strain and displacement in the parts rolling. Then the paper clarified the generated mechanism about the end concavity of shaft in the closed type of cross wedge rolling, which has great theoretical significance and engineering applied value in controlling and decreasing the end concavity in closed type cross wedge rolling and improving the parts’ end quality.

In order to raise the efficience of materials' utilization and realize the CWR without the stub bar, this paper will focus on the closed CWR forming shafts,applying finite element software DEFORM-3D to do numerical simulation calculation for the process and studying the end quality of shafts.This paper has obtained the influence rule of the forming angle α, broadening angle β, reduction of area ψ and billet diameter D four process parameters on the end quality of the closed type CWR .The research results has showed that the length of concavity goes up along with the forming angle decrease;the same as the broadening angle; while the length of concavity goes up along with the billet diameter increase.and the reduction of area ψ has made a vital influence on the end quality of shafts,this conclusion has made a solid theoretical foundation and referential value for closed CWR .

The paper applies composite technology into the field of hydraulic metal structures and hydropower construction mechanical equipment design, and presents the method of optimum design of hydraulic steel gate metal sandwich construction and simulation analysis. According to characteristics of the structure of the flat hydraulic steel gate and selecting the appropriate metal sandwich construction, this paper optimize the design of a hydraulic steel gate of metal sandwich construction from the perspective of light-weight purpose of structure. Considering the overall mechanical behavior of steel gate structures and using technology of three-dimensional modeling and numerical simulation, this paper has a numerical simulation analysis on the optimum hydraulic steel gate. Numerical simulation analysis and theoretical calculation results show the optimum structure of hydraulic steel gate is reasonably practicable.

This paper focuses on the research carried out on thin plates made of white ultra-high performance concrete reinforced by PVA fibers and 2D textile glass reinforcement. These boards should be used for facades or roof panels. The paper presents a computer and experimental analysis of the loading of thin UHPC plates. For the purpose of the experiments, three specimens of a size of 750 x 125 x 15 mm were made. The specimens were subsequently tested in the laboratory in four-point bending tests. The paper presents the process and results of the experiments. Simultaneously with the experiments, computer analyses were created in which optimization of the material and geometric parameters of the beams were carried out. The paper demonstrates the correspondence of the experimental and computer-simulated load test results.

Based on the static elastic-plastic analysis program REPFPA, the impact of concrete material elastic-brittle-plastic damage model and its numerical test methods was studied. This paper has introduced the visualization technology, preparation of pre-processing related modules and graphical visualization display and many other functions into the nonlinear dynamic program, which is convenient for users to operate and view the results. And the numerical experiments of dynamic response of cantilever beam problems and spherical shell under step load elastic-plastic problems was produced. Compared with the results of other scholars and literature, we’ll verify the validity of the research in this paper.

This paper introduces a new technique to test fatigue cracks in concrete that occur during its maintenance. The principle of the technique consists of exposing the object to pulsed mechanical excitation. As a result, acoustic waves start to propagate in the sample. Under the action of acoustic waves the dipole moments of double electric layers on the boundaries of components in concrete are changed and piezoquartz which is a part of sand and gravel is polarized. The external electric field occurs and is registered by a signal receiver placed near the object under study. The possibility of using this technique for crack nondestructive control is studied in the paper. The technique capabilities are shown by comparing the parameters of electric response on pulsed mechanical excitation when testing the defectless concrete and the same sample after developing the artificial crack in the concrete.

The gear honing is the most economical way for hard finishing an involute helical gear after hobbing and heat treatment or after shaving and heat treatment. The gear honing can also be applied to the modification of gear tooth surfaces to compensate for the distortions that occur during heat treatment process. Most published papers on the technology of gear honing describes on the principle of generated gear surface. However, the longitudinal tooth flank crowning of a helical gear with honing has not been investigated yet. Therefore, in this paper, we proposed a novel method for longitudinal tooth flank crowning of work gear surfaces by setting a crossed angle between the honing cutter and work gear axes as a linear function of honing cutter's traverse feed in the honing process. A mathematical model for the tooth profile of work gear honed by a standard honing cutter is also established. Three numeral examples are presented to illustrate and verify the merits of the proposed gear honing method in longitudinal crowning.

In this paper, the dynamic tension of bullet-proof steels processed by hot stamping are tested on MTS810 and Hopkinson bar, in which four types of steels (B1, B2, C1 and C2) are used. For each sample, the flow behavior is predicted via Johnson-Cook (JC), Modified Johnson-Cook (MJC) and Cowper-Symonds (CS) models on the basis of experimental data, respectively, and the calculation method is also introduced. After that, the errors between prediction of each model and experimental data are analyzed and discussed. As a result, the most appropriate constitutive model for dynamic flow behaviors of bullet-proof steel is proposed. Moreover, our in-house software has been developed for calculating, comparing and selecting typical constitutive models for dynamic flow behaviors of materials, which has the functions of parameters input and output, curve plotting and data storing. The work carried out in this paper will be beneficial for accurate simulation of materials deformation.

In this paper, some numerical verifications would be presented and discussed, mainly including the following three types: (1) the pure bending beam in which the structural stiffness would maintain the original value and not change along with the load; (2) the clamped arc-beam in which the structural stiffness would decrease gradually with the increment of load and the structure would be buckling at some certain load value; and (3) the cantilever beam in which the structural stiffness would increase significantly with the increment of load. For all of the above examples, the present results are in good agreement with the analytical results and numerical results in other literatures, testifying and illustrating the validity of the large rotation matrix for nonlinear framed structure, which is developed in the part 1 of this paper.

The failure criteria and calculating methods of static and seismic shear strength of masonry under combined shear-compression action have been researched in this paper. According to the least energy consumption principle and the failure criteria of orthogonal anisotropic materials, the correlated formulae of masonry under combined shear-compression action are established. The correlated formulae are in good agreement with experimental results. On this basis, the calculation formulae of the static and seismic shear strength are established. The calculation formulae uniformly use the axial compression ratio as main variable to express. By analyzing examples, it shows that calculations by formulae given in this paper are in accordance with values of "Code for design of masonry structures" (GB 50003-2011) and "Code for seismic design of buildings" (GB 50011-2010). The methods in this paper may provide important references to engineering design as well as code revision.

This paper presents a reinforcement design of five-story R/C structure with mild steel dampers in high seismic fortification intensity site. The details of the design process are listed in the paper, and the time history analyses under frequent and rare earthquake are performed on structure models with and without dampers. Through the comparison, the peak of maximum story drifts angles with damper-added structural is reduced by 38% and the distribution is more uniformly. The results show that energy-dissipation design with mild steel dampers can be a reliable and effective method in reducing seismic responses of reinforcement structure.