Automatic monitoring thermal crack growth in a thermal shock bench

摘要

Thermal damage in engine piston is checked manually at present time while the automatic thermal shock test benches have been widely used. Application of image analysis in monitoring crack is introduced in this paper. The image measure system is fixed on an automatic thermal shock bench and the images of piston are taken at certain periods. Contrasting with static image analysis, dynamic image analysis is more suitable in monitoring thermal crack. An effective curve fitting method is put forward to describe the crack through image analysis. Results show that the simplified line can well represent the original crack. With better image resolution, the image measure system is competent for measuring crack growth rate in the surface of piston.