ＣＦＲＰの低サイクル疲労寿命評価と微視的構造変化 ＣＦＲＰ［±４５°］４のＡＥ測定と微視的内部観察による検討

Abstract

In this paper, both the AE (Acoustic Emission) measurement and the microscopic observation of CFRP[±45°]4 subjected to cyclic tension-compression loading with a constant strain amplitude under a constant strain rate are conducted to verify the method to predict fatigue failure of CFRP, which was previously proposed by the present author from the microscopic change of the specimen. The method is based on the number of cycles to fatigue failure defined by using the relationship between the inelastic strain energy per cycle and cycle of loading. As a result, it is found that the relationship between the damage variable observed microscopically and cycle of loading is correlative with the relationship between the accumulated AE event count and cycle of loading. Moreover, it is also found that the number of cycles to fatigue failure determined by the proposed definition is coincide with the unique number of cycles observed from the relationship between the accumulated AE event count and cycle of loading. Thus, the method is considered verified from the microscopic structural change of CFRP[±45°]4.