形状记忆纤维热粘弹性基体复合材料的力学行为

应用热粘弹性理论和Voigt混合律,在变温场中针对马氏体逆相变过程建立了NiTi形状记忆纤维热粘弹性基体复合材料的应力-应变关系,在逆相变过程和基体呈现热粘弹态阶段,由于基体松弛其模量减小,在跃阶拉应力的作用下,复合材料的压缩应变迅速增大,纤维回复应力先增大后减小;在跃阶拉应变的作用下,复合材料的应力增加先变缓然后加快直至稳定,较高的温度和材料参数对NiTi纤维热粘弹性基体复合材料的力学行为和纤维的作动性能有明显的影响.

Mechanic behaviors of the thermoviscoelastic matrix composites with shape memory fiber

A stress-strain relation of the thermoviscoelastic matrix composites with pre-strained NiTi fiber is proposed in the field of variable temperature based on the thermoviscoelasticity theory and the rule of mixtures, and in view of the process of martensite reverse transformation. During the reverse transformation and the thermoviscoelastic state of matrix, due to matrix relaxation modulus decreasing,the results show that upon the step constant stress, the compression strain of the composites increases rapidly, and the recovery stress of the NiTi fiber increases then decreases; Under the step constant strain, the increase of the composites stress become slow then fast, till steady. The behaviors of the composites, and the NiTi fiber actuation performance are influenced by higher temperature as well as the material parameters.