ENNDOU Norio Nagano Industrial Senior Polytechnic, Dept. of Civil Eng. Research Associate, 助手 (10213597)
OUKAMI Tosiyuki Shinshu University, Faculty of Engineering Associate Professor, 工学部, 助教授 (80152057)
TOMIDIKORO Gorou Shinshu University, Faculty of Engineering Professor, 工学部, 教授 (30021025)
SASAGAWA Akira Shinshu University, Faculty of Engineering Professor, 工学部, 教授 (00017922)
|Budget Amount *help
¥1,900,000 (Direct Cost : ¥1,900,000)
Fiscal Year 1995 : ¥900,000 (Direct Cost : ¥900,000)
Fiscal Year 1994 : ¥1,000,000 (Direct Cost : ¥1,000,000)
This research investigates the applicability of homogenization method to structural analysis by some numerical experiments, in detail. In order to analyze the stress of composite materials by means of FEM,effective coefficients of the materials, such as average elastic constants must be determined by some method. Homogenization method is one of mathematical means to obtain these constants. In this research, fiber-reinfored composite materials, sometimes used as thermal materials, is analyzed in detail. Due to the thermal insulating property that most fiber-reinforced composite materials possesses, ther application under high temperature circumstances, specially like using in space vehicles, is increasing. Consequently, it is quite necessary to establish a scientific and effective method to analyze heat stress and to deal with heat conduction. The research takes the advantage that the homogenization method is applicable to any cases that composite materials is fiber-reinforced in one, t
wo or three directions, namely, it is not needed to consider geometrical limit so seriously. Hence this method is applicable for evaluation of average heat conduction rate and expand rate. A process to evaluate these parameters is given.
In this term of project, research results gained are roughly summaried as follows :
(1)The research shows that for elastic and thermal elastic problems, it is feasible to apply homogenization method to evaluate average elastic constants and heat expand coefficients. It is found that even local stress of the composite materials can also be obtained with a high degree of accuracy by this method.
(2)With reference to unsteady heat conduction problems, if the heat conduction rate of inclusive materials is much higher than the one of fundamental materials, the constants can be evaluated exactly. Coversely, if the heat conduction rate of the former is much lower than the latter, the difference of average temperature can be found.
(3)For heat conduction or its quasi-training problems, the research reveals that if heat conduction rate of fundamental is much higher than the one of inclusive materials, homogenization method is also feasible. Less