高密度聚乙烯垫片的非线性压缩-回弹性能测试

为研究高密度聚乙烯（HDPE）垫片在非线性棘轮实验中的应力率和温度相关性，使用RPL50型蠕变疲劳试验机，对HDPE垫片在循环压缩载荷下的压缩-回弹效应进行了实验研究，建立了HDPE压缩-回弹的本构预测模型。结果表明，HDPE的棘轮变形随着温度增大而增大，当温度大于80 ℃时棘轮变形随温度的升高大幅度增加，在80 ℃时，为常温下的4倍；随着应力率的增大累积的棘轮应变有所下降，由应力率为1 MPa/s时的8.99%下降至0.01 MPa/s时的14.23%，即温度和应力率显著影响HDPE的压缩-回弹性能。本文模型能够较好预测HDPE在不同温度与应力率工况下的非线性压缩-回弹性能，在HDPE垫片的工程设计方面具有一定的应用价值。

Nonlinear Compression-Resilience Performance Test of HDPE Gaskets

To investigate the stress rate and temperature correlation of high-density polyethylene （HDPE）gaskets in nonlinear ratchet experiment， the RPL50 creep fatigue testing machine was used to evaluate the compression-resilience performances of HDPE gaskets under cyclic compression loads.Through experimental research， a theoretical model was established to predict the compression-resilience performances of HDPE gaskets. The results show that the ratchet deformation of HDPE increases with the temperature rises， and when the temperature is higher than 80 ℃， the ratchet deformation increases greatly. It can reach 10.65% at 80 ℃， which is quadruple that at room temperature. With the increase of the stress rate， the cumulative ratchet strain decreases from 8.99% at the stress rate of 1 MPa/s to 14.23% at the stress rate of 0.01 MPa/s. In conclusion，temperature and stress rate significantly affect the compression-resilience energy of HDPE. The model in this paper can better predict the nonlinear compression-resilience performance of HDPE under different temperature and stress rate conditions， and has certain application value in the engineering design of HDPE gaskets.