Estimation of Strength and Fracture of Advanced Composite Materials

1. 1991年8月与北海道大学的Ellyin教授和Krempl教授详细讨论了本研究项目的方法和时间表。制定了详细的研究计划。综合了本课题研究人员在循环塑性、粘塑性、弹塑性、损伤力学和断裂力学等方面的研究成果。然后讨论了先进复合材料机理研究的适用性。本课题研究人员参加了1991年美国机械工程学会年会，会上有很多关于先进复合材料的介绍。世界各地的研究人员进行了许多有益的讨论。然后，明确了复合材料研究中存在的问题。对复合材料的粘弹塑性、循环塑性、疲劳和疲劳损伤进行了研究。从宏观的角度考察了材料力学对复合材料性能的适用性。利用弹塑性或粘塑性发现了清除基体材料和增强材料之间相互作用的可能性。很明显，断裂力学和损伤力学能够。适用于研究基体材料和增强材料之间的相互作用。可见，微观组织的疲劳破坏与宏观组织的疲劳破坏相似。因此，宏观组织的疲劳破坏规律可以用来解释微观组织的疲劳破坏。用弹塑性、粘塑性、断裂力学和损伤力学来解释复合材料的微观变形是可能的。这项研究的结果在1992年9月举行的JSME/MMD（日本机械工程学会/材料与力学分会）92年年会上进行了报告。

1. The method and schedule of this research program were discussed in detail with Prof. Ellyin and Prof. Krempl at Hokkaido University on August, 1991. The detailed plan for the research was made.2. The studies of the investigators of this research program, such as cyclic plasticity, viscoplasticity, elastoplasticity, damage mechanics and fracture mechanics, were assembled. then, those applicability to research on mechanism of advanced composite materials was discussed.3. The investigators of this research program attended the annual meeting '91 of ASME(America Society of Mechanical Engineering) which had a lot of presentation of advanced composite materials. Many instructive discussions were maad with researchers in the world. Then, problems of the research on composite materials were made clear.4. The experiments were carried out to investigate viscoelast-plasticity, cyclic plasticity, fatigue and fatigue damage of composite materials. The applicability of material mechanics to those behavior of composite materials was examined from the macroscopic point of view.5. The possibility to clear the interaction between matrix materials and reinforced materials was found using elastoplasticity or viscoplasticity. It was also clear that fracture mechanics and damage mechanics were able to. apply to investigate the interaction between matrix materials and reinforced materials.6. It was clear that fatigue failure of microstructures was similar to that of macrostructure. Then, The fatigue failure law for macrostructure might be used to explain fatigue failure of microstructures.7. The possibility to explain the microscopic deformation of composite materials was found using elastoplasticity, viscoplasticity, fracture mechanics and damage mechanics.8. The results obtained from this research were reported at the annual meeting '92 of JSME/MMD(Japan Society of Mechanical Engineering/Material and Mechanics Division) held in September 1992.