Study On Numerical Simulation Technology Of Thermal Stress Field In Sand-Casting Process

Numerical simulation of casting's solidification processes is the advanced region in foundry develop, it is also the only way via which to modernize the traditional foundry industry. Compared with temperature field simulation and fluid field computation, the stress/strain field analysis starts up later and presently is yet immature, so becomes the hot spot of macro simulation. Stress field calculation can help foundry engineers predict and analyze flaws such as crack, deformation and residual stresses so as to present scientific reference to eliminate defects caused by stress and strain, optimize foundry technology and increase dimensional precision and stability of castings.In this thesis, the development of numerical simulation of thermal stress field during casting process, the method of numerical calculation and the application trend of simulation software are summarized. The character of thermal-stress field during casting process has been introduced in brief. An elastic-plastic 3D FEA model of the transient temperature field and thermal-stress field is theoretically built. And a mathematical model of the initial condition, boundary condition, and latent heat disposal is built as well.Select the FEM software—ANSYS, carry out the study on numerical simulation of thermal-stress field. Considering to the character that the material's performance changes along with temperature, nonlinear analysis in the procedure is adopted. An FEA analysis is finished for the stress frame 3D temperature field and thermal-stress field of the typical casting-stress frame. The result indicates that the numerical value simulation of 3D temperature field can basically reflect the dynamic change of the temperature field in the casting cooling process. With considering the phase change stress, the results of thermal-stress field calculation are fairly approach to the theory analysis and the references literature. Treatment methods of eutectoids phase and casting-sand boundary are verified well.At last, for engineering application, a piece of seat casting has been analyzed by using the thermal-stress field simulation methods in this thesis. The calculated results are in agreement with the practical results, which demonstrates that methods are competent for the practical application of engineering.