Theoretic Simulation And Experimental Analysis Of The Stress In The Interface Of Composites

The effect of the interface in the functional composites with extreme or unusual thermal expansion properties is more complex than the MMCs(metal matrix composites). However, till now few people have studied the interface effect, and the design of the functional composites has also been made without considering the interface effect. To design this functional composites better, the studies of the magnitude and the distribution of thermal stress in the interface and the components are very important.In the paper the mathematical and physical strength models on the distribution of the thermal stress in the interface and the components during the heat treatment were established. The distribution of the thermal stress in the interface and the components were simulated by the finite element software ANSYS. Both results are basically identical.The Fe64Ni36 (Invar alloy) and Mn75Ni15Cu10 alloy were chose as components due to the larger difference of thermal expansion coefficient. The composite made of the above two components was fabricated through cold roll. The stress of the composite as a function of thermal cycling times was investigated by means of the resistance and X-ray diffraction methods. The relationship between the resisitivity and the stress was simulated by MATLAB software. Based on the mathematical and physical strength model, the resistivity in different thickness of the composite was attained, and the total resistivity was attained through the integral of thickness, which is basically identical with the tested resistivity.The change of the stress in the composite during the thermal cycling treatment can be evaluated through the analysis of resistivity. The parameters of thermal treatment also can be determined, such as the temperature, the time and the cycling times.