Deformation of casting during the solidification process has puzzled many engineers and scientists for years. In order to attain the goal of near-net forming by casting, numerical simulation is a powerful tool. Traditional methods compute the thermal stress of both the casting and the mold. This method suffers the problem of massive calculation and failure of convergence. This paper proposes an improved Mold Surface Element Method, the main idea of which is to use the surface elements instead of body elements to express the interactions between the casting and the mold. The proposed method shows a high computation efficiency and provides satisfactory precision for engineering. Two practical casting products were used to verify the proposed method. The simulated results agree well with those observed in practical products. The proposed method is believed to benefit production practice and to provide theoretical guidance.
Tao ChenYu-long TangDun-ming LiaoLiu CaoFei SunZi-hao TengDi Wu
When castings become complicated and the demands for precision of numerical simulation become higher,the numerical data of casting numerical simulation become more massive.On a general personal computer,these massive numerical data may probably exceed the capacity of available memory,resulting in failure of rendering.Based on the out-of-core technique,this paper proposes a method to effectively utilize external storage and reduce memory usage dramatically,so as to solve the problem of insufficient memory for massive data rendering on general personal computers.Based on this method,a new postprocessor is developed.It is capable to illustrate filling and solidification processes of casting,as well as thermal stess.The new post-processor also provides fast interaction to simulation results.Theoretical analysis as well as several practical examples prove that the memory usage and loading time of the post-processor are independent of the size of the relevant files,but the proportion of the number of cells on surface.Meanwhile,the speed of rendering and fetching of value from the mouse is appreciable,and the demands of real-time and interaction are satisfied.
