Stress Analysis by Finite Volume Method for Prediction of Porosity and Deformation Defects of Spheroidal Graphite Castings

A 3-D elastic stress analysis code using Finite Volume Method (FVM) has been developed and applied to porosity and deformation defects prediction in spheroidal graphite (SG) cast iron. In the FVM method, a casting is represented in a finite number of small cubic elements. Displacement components are defined at the volume center of each element. Stresses are evaluated at the surface center of the element. Then, equations of the force balance on the cubic element are discretized in terms of displacement. The resulting equations are solved by the linear equation solver like the conjugate gradient method. Calculating stress distribution and deformation of several castings using this method confirmed that their results are almost identical with those of FEM, and physical memory requirement for the FVM is less than 20% for the FEM. Consequently this study showed that FVM can be a practical method for the stress analysis to predict porosity defects and casting deformation in a complicated shape casting which consists of a large number of the elements.