1·The reason is that both temperature and stress combine to affect the accumulation of inelastic strain.
而在低温保温阶段，应力虽然较高，但温度较低，非弹性应变也不明显。
2·The modulus of the material decreases and the inelastic strain increases with the increase of tension stress, and the composite exhibits a largely non-linear stress-strain behavior up to rupture.
随着应力的增加，材料模量减小，非弹性应变变大，复合材料的应力-应变行为表现为非线性直至断裂。