HDPE土工膜温度应力及其应力松弛评价

利用弹性理论和粘弹性模型提出了温度应力和温度应力松弛的评价方法.采用拉压传感器、热电偶以及位移计研究了环境温度变化对HDPE土工膜温度应力的影响,以及HDPE土工膜温度应力伴随时间变化的规律.实验结果表明:HDPE土工膜的温度应力伴随环境温度的变化而变化,当环境温度下降时将导致HDPE土工膜收缩产生温度应力;在同一温度条件下,HDPE土工膜发生了温度应力松弛现象.运用提出的评价方法对温度应力及其应力松弛进行了评价,并与模拟试验结果进行了对比,温度应力松弛现象的解析结果与实验趋势一致.所提出的评价方法对HDPE土工膜温度应力及其松弛现象解析具有实际使用价值.

Evaluation of temperature stress and stress relaxation properties of HDPE sheet

The evaluation formula of temperature stress and stress relaxation is proposed by using the elasticity theory and visco-elastic model.The effect of temperature on the temperature stress and the variation regularity of temperature stress with elapsed time was investigated by loadcell,thermocouple,and displacement gauge.Test results show that the temperature stress within the high density polyEthylene(HDPE) sheet changes with environment temperature.The temperature stress within the HDPE sheet occurs when environment temperature decreases;And the stress may decrease rapidly as the temperature keeps unchanged,a phenomenon considered to be the stress relaxation.The temperature stress and the stress relaxation are analyzed by the proposed method,and a comparison shows that the calculation results are fairly close to the experiment value.Thus the proposed evaluation method for the temperature stress and the stress relaxation is applicable.