高分子系複合材料の温度環境下における疲労寿命の推定

抄録

A prediction method of fatigue strength of polymer composites for an arbitrary frequency, stress ratio, and temperature is proposed. The method is based upon the four hypotheses, (A）failure mechanism for CSR (constant strain-rate）, creep, and fatigue failure is the same, (B）the same time-temperature superposition principle holds for all failure strengths, (C）linear cumulative damage law is applicable for specimen failure under nondecreasing stress process, and (D）fatigue strength shows linear dependence upon stress ratio. Flexural CSR, creep, and fatigue strengths of satin-woven CFRP laminates were measured at various loading rates and temperatures. The validity of hypotheses B, C, D, and the applicability of this prediction method were experimentally confirmed by creep tests and fatigue tests of different conditions of loading rate and temperature. It was also confirmed that the hypothesis A is not necessarily always for this prediction method through discussions.