ANALYSIS OF MECHANICAL BEHAVIOR OF TEMPERATURE-DISTRIBUTED STRUCTURES BY USING A MATERIAL FUNCTION

초록

A new concept of the temperature-dependent material function applicable to the analysis of tructural behavior of solids has been proposed. That is a basic study for the analysis of mechanical systems operated in various temperature conditions. Traditionally, the analysis of mechanical systems which consisted of the general engineering material, has been carried out based on the stress-strain relationship in the infinitesimal deformation of linear elastic materials. In addition, the whole mechanical systems were assumed to be at constant temperature for the most analyses. The influence due to thermal expansion coefficient is probably the only factor accounted for the temperature difference. However, material properties are known to have strong dependence on temperature. Therefore, it is difficult to accurately predict the real structural behavior dependent on temperature by using the conventional analysis methods, although they are still useful for obtaining the analytical solution with mathematical techniques. The differences in the actual problem are thought to be significant. In this study, we approach the problem using the thermal conductivity and the elastic modulus as the function of temperature. By using the finite element method, an asymptotic solution is to be obtained. To check the effectiveness of the method, a problem for one-dimensional cantilever beams made of pure iron was carried out by using the proposed method. First of all, the analysis resulted in the temperature distribution in the cantilever beam and the end side temperature. As a result, the material function analysis appeared to be significantly different from the constant value analysis. The end side temperature by the material function analysis is higher than that of the constant value analysis by 298K. This means that it is hard to predict the end side temperature using the constant value analysis for the case with long length and lower heat flux. Secondly, the tensile force acting on the