高孔隙度泡沫塑料的一种近似非线性本构关系

APPROXIMATE NONLINEAR CONSTITUTIVE RELATION OF FOAMED PLASTICS WITH HIGHER POROSITY

根据高孔隙度泡沫塑料杨氏模量满足平方律关系的理论和实验结果，并通过对泡沫塑料泊松比的合理近似，在假设基体材料服从幂律本构关系的基础上，研究了高孔隙度泡沫塑料的非线性本构行为，得到了用于确定非线性本构关系的应变势函数，给出了描述高孔隙度泡沫塑料非线性力学行为的一种有效、合理的本构关系的形式。此外，由此得到的泡沫塑料屈服应力与前人按照量纲分析方法得到的低密度闭孔泡沫塑料的结果相一致。

Based on the square relationship of foam plastics with higher porosity which has been derived by theory and experiments and on the suitable approximation for Poissons ratio of foam plastics, the nonlinear stress strain behavior of foam plastics is investigated by supposing the matrix to be power law material. The strain potential to determine the nonlinear constitutive relation is obtained and a constitutive relation is derived so that it can fit well with experimental data of compressive tests. The yield stress of foam plastics obtained from the derivation agree with the result of lower density close cell foams.