126 応力比の影響を考慮した複合材料の疲労損傷力学モデル

概要

論文の詳細を見る
A phenomenological fatigue model for describing the effect of stress ratio on the off-axis tensile fatigue behavior for unidirectional fiber-reinforced composites has been developed. First, empirical fatigue parameters are briefly reviewed. The conventional strength ratio is useful in manipulating the directional nature of the off-axis fatigue strengths. Using a modified strength ratio that considers the effect of stress ratio, we can substantially remove both the off-axis angle dependence and the stress ratio dependence of the off-axis T-T and T-C fatigue data, and obtain a master S-N curve which is almost independent of the off-axis angle and stress ratio. The modified fatigue strength ratio is then generalized in terms of the non-dimensional effective stress that corresponds to an extension of the conventional strength ratio. By using the modified non-dimensional effective stress, the fatigue damage mechanics model proposed in the previous study is further extended to cope with both the off-axis angle dependence and the stress ratio dependence of the off-axis fatigue strengths. The capability of the proposed fatigue model to reproduce the off-axis S-N relationships for different stress ratios is demonstrated through comparisons with experimental results on unidirectional glass and carbon fiber-reinforced polymer matrix systems.
一般社団法人日本機械学会の論文
2002-10-10