压缩条件下发泡PS黏弹塑性力学模型研究

Study on mechanical model of viscoelastic plasticity of expanded polystyrene under compressive loading

为提高发泡聚苯乙烯(EPS)工程应用的长期稳定性,分析了压缩条件下EPS的力学性能。实验中EPS块体的受压变形呈现出黏弹塑性特征,并可分为3个阶段。随着加载速率的增大,屈服应变略微增大,但对切线弹性模量影响较小,在实验的基础上建立了表观密度与3个EPS压缩实验参数的关系。构造EPS块体的压缩黏弹塑性模型与实验结果的误差为0.37%。比较模型预测值与现场实测的压缩变形结果,结果表明两者图形趋势较为一致,用该模型可预测EPS块体的压缩变形。

Mechanical properties of expanded polystyrene （EPS） were analyzed under compressive conditions, aimed at improving the long-term stability of EPS in engineering applications. The compressive deformation of EPS in block form exhibited features of viscoelastic plasticity in the experiments; its compressive behaviour could be characterized by three stages. A rise in rate of adding load led to a slight increase in the yield stress but no effect on the tangent elastic modulus. The relationship between apparent density and 3 compressive experimental parameters of EPS was established on the basis of the experiments. The system deviation between the constitutive model for viscoelastic plasticity of EPS in block form and the experimental data was 0.37%. The compressive deformation of EPS measured in-situ and its counterpart predicted based on the model were compared; the main characters reflected in the profiles acquired from the two approaches appeared to be rather coincident. The model was available for forecasting the compressive deformation of EPS in block form.