The numerical simulation of the Y-type three-roller two stands cold rolling stainless steel/carbon steel double metal composite seamless steel tube process was conducted through the finite element analysis of the elastic-plastic by applying the MSC.MARC software. Based on the numerical simulation, the character of stress and strain distribution parameters during the Y-type three-roller two stands cold rolling were obtained by the finite element analysis, and acquired the section pass deformation figure. The distribution of the axial stress, circle stress and radial stress were drawn below the Y-type mill along the circle. The mechanism of the tube cold rolling process and the effect of the forming steel tube both the diameter and wall thickness accuracy were explained according to the stress distribution. The results of the research can be applied to the design of the technical parameters in the forming process.

According to the chatter phenomenon of 3rd stand of a steelworks six-roller tandem cold mill (TCM), vertical vibration of tandem cold mill was simplified to eight degrees of asymmetric freedom mass-spring system. Virtual prototype model on vertical vibration of tandem cold mill was established and natural frequencies and main vibration mode of mill were solved by using automatic dynamic analysis of mechanical systems in software ADAMS. The modal coordinates of main vibration mode of the mill were referred firstly and obtained; the maximal mode of vibration system was found and finally discovered the fifth-octave-mode chatter was the probable vibration of the mill.

Both the method of engineering and nonlinear finite element method have been used to the analysis and optimum design of the 30 in. marine riser with the screw thread. Two load steps have been used in the finite element analysis including the processes of both assembling and applying the load of piling, and the nonlinear contact between marine risers has been considered in the simulation. Numerical results show that the stress in the marine riser increase rapidly when the magnitude of interference of the screw thread change slightly. By the way to change interferential magnitude of the screw thread, the maximum stress of Von Mises decrease from 681MPa to 381MPa and contact stress decrease from 238MPa to 122MPa. The engineering practice over 100 piles in offshore platform has shown that the numerical results are good.

Objective To set up a three-dimensional (3-D) finite element (FE) model of Less Inwasive Stabilization System (LISS) intreating distal femoral fractures(AO /33-A3), and make preliminary biomechanical analysis, which can provide a scientific basis for future clinical application. Methods To obtain information of the spatial structure of the femur by CT scan, then to build their three-dimensional solid model using of software, and use three-dimensional reverse engineering to obtain three-dimensional model of LISS. The model was assembled using the ABAQUS, then meshed and simulated axial compression force, the stress distribution of femur and LISS plate. Results The largest stress of the LISS focuses on the edge of the plate and the region which is close to the femur.

Objective To understand the stresses distribution and process of damage evolution of both matrix and fiber in the defect cartilage under load of compression. The numerical results may provide a reference to both of the design for cartilage alternatives and clinical repair of defect cartilage. Methods The thickness of different layers of cartilage was obtained by a kind of experiment, in which the displacement in different layers zone cartilage under the compression load was obtained by the digital correlation technique. The multi-layer cartilage model with fiber and defect was established by the multi-physics analysis software ANSYS, with the different layers of the cartilage refer to the experimental results. According to the strength condition, the cartilage damage evolution process was simulated by the method of modifying the stiffness of the elements. The influence of the different defect depth to the damage evolution of cartilage was considered in parameter study. Result The simulation results have shown that the stress distribution in matrix was related to the cartilage defect depth. The minimum stress was distributed in the deep areas and below the damage area, stress concentration was located in the both sides of the defect area in the cartilage matrix, and the damaged area developed gradually from surface to deep, the maximum stress located at both sides of defect area. The stress distribution of cartilage fibers related with their location, the compressive stresses are mainly distributed in the middle and deep area, which are greater than those of undamaged. Conclusion In the process of damage evolution, the damaged area gradually developed from the surface to the deep. In the case of defect value of 60%, the maximum equivalent stresses in matrix will be increased in the process of damage evolution; in the case of defect value of 5%, the maximum axial stresses in fibers will be increased in the process of damage evolution.