Finite Element Analysis On Strength Of Weld And Rivet In High Speed Train

Connections such as weld and rivet are very important for the safety design in the high-speed train. The qualities of the connections can obviously affect the safety and the service life of the train. Weld and Rivet are selected in current work for numerical studies. According to the recommendations from the International Institute of Welding (IIW), the stresses on the key components in the high-speed train body are analyzed by use of ANSYS based on hot spot stress theory. ABAQUS/Explicit software are further used to simulate the forming process of the rivet. The main researches are summarized as below:The first chapter introduces the importance and significance of connections in design in the high speed train, and the research status of the domestic and foreign scholars, further application of the hot spot stress method to predict the stress reliability of the key parts in structure, and the finite element factors that affect the hot spot stress. Numerical simulation of the entire process of riveting are used to design the process parameters, and to provide recommendations to the process. The rivet force is obtained in the actual engineering applications by optimizing the process parameters and the loads, to eliminate various defects that may occur in the process.The methods to determine the type of the hot spots and to select appropriate extrapolation method recommended by the International Institute of Welding for the window weld characteristics of the high-speed train body are given in the second and fourth chapters. According to substructure method, window model extracted and refined to achieve the â…¡W recommendations, the computational results show that the hot spot stress method has strong mesh sensitivity. In contrast to hot spot stresses obtained by interpolation under different load conditions, it is showed that the hot spot stress is always smaller than the finite element results. The two results are the more obvious different, the greater the stress gradient around the hot spot. To compare the two methods of extrapolation, it found little difference between the two-point extrapolation method and three-point extrapolation results.The riveting process of the headless rivet with variable cross-section was analyzed in the third and fifth chapters. The physics of the model assumptions are given and riveting process is divided into five stages according to rivet deformation characteristics. Riveting process for headless rivet is simulated by the method coupled Lagrange and Euler method to study the geometric model of the modeling process, meshing, contact, the constraint conditions and so on. It learned from the results that rivet deformation, stress distribution, and riveting force variation over time. Comparing the rivet forming results with the same rivet length, diameter, but different header height, it shows that with the header height gradually decreased, the bigger rivet deformation and riveting force, the better the quality of the connection Comparing the rivet forming results with the same rivet diameter, header height, but different rivet height, it finds the rivet parameters with not only good connection quality but also to save raw materials.