柔性硅泡沫薄片的短时松弛行为研究

根据多孔硅泡沫材料的单轴压缩和应力松弛实验,利用最小二乘法的LM法拟合得到硅泡沫材料的本构关系.基于上述模型开展了组合结构中多孔泡沫薄片应力松弛行为的数值模拟,得到了短时松弛过程中硅泡沫结构件的应力变化规律.

A STUDY ON THE STRESS RELAXATION PROPERTIES OF SILICONE FOAM CUSHION IN COMPOSITE STRUCTURE

Based on the experimental data of uniaxial compression and stress relaxation,stress relaxation model of five parameters of compressible silicone foam was obtained by using least square method.And utilizing the constitutive relation,the nonlinear viscoelastic constitutive model is applied to simulate the viscoelastic behaviors of porous silicone cushion in composite structure,and the pattern of stress relaxation of the cushion is obtained in process of short-time.A comparison is carried out with the data of uniaxial compression relaxation experiments,the results indicate that,to the silicone foam material,the experiment shows good agreement with theoretical results,and the constitutive models can predict the relaxation characters of silicone foam materials.To the silicone foam structure,the actual loading test process is more or less different from that required theoretically,and the difference between them would influence the relaxation rate calculated from the experimental results.