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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]

This paper deals with the simulation of UNS A92024 aluminium alloy cutting processes. In particular, 2D and 3D Finite Element Method (FEM) simulations were carried out in order to estimate cutting forces and chip morphology during turning operations. The material is modelled with two different set of parameters for the Johnson-Cook's (J-C) constitutive equation and a failure Cockroft and Latham's model exploited considers damage. The comparison between the predicted chip morphology and principal cutting forces at varying of J-C parameters and cutting regimes with those experimentally found are presented and discussed. The paper shows the importance of damage criterion in the cutting forces, during the simulation, especially in 3D. [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]

Conical parts have a lot of usage in aerospace and special industries. These parts usually formed by spinning, explosive forming, multistage deep drawing. Due to their bad forming condition in conventional methods, some new forming methods have been explored to increase the drawing ratio, hydroforming is one of the more effective methods. In this study hydrodynamic deep drawing assisted by radial pressure is used to form the conical-cylindrical parts. Commercially pure copper is used in this research. The process is initially simulated using the FEM solver ABAQUS. Experiments have been conducted with different punch geometries. The punch geometries consist of conical and cylindrical wall segments. This paper examines the effect of cone angle on drawing ratio and thickness distribution of conical cups. Using the measurements of thickness variations on the cup wall, the quality of the cups drawn has been evaluated. The results of the study demonstrated that increasing the cone angle has a important effect on drawing ratio and cause uniform thickness distribution. Also it was concluded that the conical-cylindrical parts had two critical regions at contact area of punch tip with the blank and the transition zone between the conical and cylindrical portions that variation at cone angle affected these regions and resulted to variation of these areas. It was proved that the results from the experiment and the simulation were in a reasonable agreement. [ABSTRACT FROM AUTHOR]

Cage roll forming is one of the advanced methods of cold roll forming process which is used widely for producing ERW pipes. In addition to decreasing the production cost and time, using cage roll forming provides smooth deformation on the strip. Few studies can be found about cage roll forming because of its complexity, and the available knowledge is experience-based more than science-based. In this paper, deformation of pipes with low ratio of thickness/diameter is investigated by 3D finite element simulation in Marc-Mentat software. Edge buckling defect in cage roll forming of low ratio of thickness/diameter pipes is very important. Due to direct influence of longitudinal strain on the edge buckling phenomenon, longitudinal strains at the edge and center line of the strip are investigated and high risk stands are introduced. The deformed strip is predicted using the simulation results and effects of each cage forming stage on the deformed strip profile are specified. In order to verify the simulation results, strip width and opening distance of the two edges in different forming stages are obtained from the simulations and compared with the experimental data which were measured from the production line. A good agreement between the experimental and simulated results is observed. [ABSTRACT FROM AUTHOR]

Material which has character exists on thermoplastic, battery, coating material, and etc. The existing event is in transient’s condition. Transient situation on geometrical shape and complex boundary condition is difficult to solve by analytical method. The solving transient’s situations will be done using finite element method (FEM) that is solved by computer. Bar metal that is got thermal loads in the period of long time then it will be soaked into liquid to change metal bar physical property it. For this need careful analysis that is safety on metal bar utilized on structured component and also constant nuclear component guarded. It should be done using modeling and computer simulation. This paper, describes about transient temperature distribution analysis that is observed from center, corner edge, and center external surface on cross section got from a rectangle shape which is suddenly quenched up to 3 seconds into liquid with temperature t£, convective surface coefficient h and initial temperature t0. The Characteristic is an orthotropic having X-axis conductivity value different from X-axis conductivity value. The solution of problem mentioned above is done by software application based on finite element method. [ABSTRACT FROM AUTHOR]

Solar thermal power generation systems, including direct steam generation, require isothermal energy storage systems for a saturation temperature range between 190° C and 310° C. One option to fulfill this requirement is the application of phase-change materials to absorb or release energy. In this paper, the basic concept of latent heat storage system is described, and a model of phase-change heat transfer of latent heat storage thermal unit for thermal energy storage system is built. Base on the practical thermo-physical properties of phase-change materials, Quasi-Steady State temperature distribution of phase-change heat transfer is analyzed under low Ste number. Numerical simulation (finite element method) taking account into the sensible heat is adopted and the results prove that the Quasi-Steady State temperature distribution obtained from theoretical is in good agreement with the results of numerical simulation. For a latent heat storage system with low Ste number characteristic, Quasi-Steady State solution can be used as the theoretical calculation foundation for engineering design. [ABSTRACT FROM AUTHOR]

The simulation of high-velocity impact and penetration is inhibited by complex material behavior and large deformations. Lagrangian formulations best model complex materials because history-dependent variables and material boundaries are not advected. However, Lagrangian finite elements are limited by large deformations. Recently, meshfree particle methods have been used to avoid such limitations, and have demonstrated greater accuracy than traditional erosion methods (wherein deformed elements are removed). Though the variable connectivity of particles enables them to model large deformations, it requires more computational effort than (fixed-connectivity) elements. Therefore, an algorithm was designed to convert deformed elements to particles, thus providing the ability to model large deformations where needed, while maintaining the efficiency of elements elsewhere. This combination is essential in three dimensions, where problem size demands efficiency. In this paper, the conversion algorithm is demonstrated for several three-dimensional simulations of high-velocity impact and penetration. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]