The method of caustics, which is one of nondestructive optical measuring methods, is powerful technique to evaluate stress intensity factors (SIFs) and contact forces using caustic images formed from their stress concentrated areas. The shape and size of the caustic images depends on conditions of material, thickness, optical setup, etc. Caustic image simulation is applicable to evaluate the values of SIFs and contact forces, and also to set the experimental conditions before tests. To widely use the method and simulation of caustics, in this paper, a Java program has been developed for online simulations via web. The site opened is http://www.kouku-k.ac.jp/〜t-tamiya/index.html.
