A Color/Gradient Pre- and Post- Processor for 2-D Finite Element Stress Analysis Programs

A pre- and post-processor of finite element data for use on a color graphics microcomputer has recently been developed. The entire data file, which includes information for gridding, material properties and loading schemes, can be generated and debugged locally on a microcomputer before being sent to the mainframe computer. Before the emergence of advanced, large memory microcomputers, the preprocessing was performed interactively with the mainframe computer which consumed a considerable amount of wall-clock time. Another advantage of pre-processing on microcomputers is that the mainframe is less burdened by interactive usage and is returned to the batch mode allowing it to perform more jobs in less time. The post-processor transforms the output data into a representative color, denoting a component, and intensity of that color, denoting a normalized stress level in the element. This allows the analyst to examine the state of stress in a multi-component structure in a single picture. For effective stress the stresses are normalized with respect to the material yield strength in each component. For the three unidirectional and shear stresses the elements comprising each component are searched for the maximum value and stresses are normalized to that value. Keywords: PREPPY computer program; Computer printouts. (Author) Original contains color plates: All DTIC/NTIS reproductions will be in black and white.