Study On Numerical Simulation Of 3-D Thermal Stress Fields Of Steel Castings During Solidification Process

The numerical simulation of thermal stress fields during casting process can help foundry engineers predict and analyze such defects as crack,deformation and residual stress, and present scientific reference to optimize casting process,control defects,guarantee the dimensional accuracy of castings and stability,get high quality production.In this thesis, the development of numerical simulation of thermal stress fields during casting process,the method of numerical calculation and the application trend of simulation software are summarized. According to the character of thermal,stress fields during casting process, built thermal elastic-plastic model and equation after solidification of casting process, analyze casting/mold boundary condition,the mechanics performance parameter of material during high temperature, and adopt indirect method calculate thermal stress.Select the FEM software—ANSYS, carry out the study on numerical simulation of thermal stress fields. Considering to the character that the material performance changes along with temperature, nonlinear analysis in the procedure is adopted. Based on the disposal principle of thermal physics performance of material,initial condition,boundary condition,latent heat during solving temperature fields, analyze and calculate stress of stress frame,hydraulic turbine vanes,goblet shell. The simulation results of stress frame are same with qualitative theoretical analysis. Using the characteristic of partition modeling, select one—eighth model of goblet shell, the results show that the position of stress concentration coincides with the facts. Adopting coarse grid and fine grid to calculate the residual stress of axial flow blades, the simulation results show that the position of stress concentration coincides with relevant reports. Study on the numerical simulation of thermal stress fields is research focus. In this thesis, adopt numerical simulation method to calculate the stress and strain. Offer a new method to simulate stress fields for CASTSoft software.