高温波齿复合垫片的循环压缩回弹性能

Cyclic Compression-Resilience of Flexible Graphite Corrugated Metal Gaskets at High Temperature

研究了柔性石墨金属波齿复合垫片在500℃时的加载速度对循环压缩回弹性能的影响.在试验温度为500℃时,对垫片进行加载速率分别为0.5 MPa/s和1 MPa/s的循环加载试验,得到垫片的应力-变形量曲线;通过计算压缩率和压缩模量,再拟合出相应的压缩-回弹本构方程.结果表明,500℃时波齿复合垫片的压缩模量随加载速率增大而增大;经过第一次压缩后,在随后的循环压缩过程中垫片的压缩模量变化较小,但显著高于初始压缩模量;垫片的最大压缩量均随循环次数而增加,表现出明显的棘轮效应,为保证连接紧密性需考虑垫片变形量;根据文章拟合的回归系数可以推测出在不同加载速率下,该类型波齿复合垫片的压缩回弹性能.

The effect of loading speed on the cyclic compression and resilience performance of flexible graphitemetal corrugated composite gasket was studied.The stress-deformation curves of the gasket were obtained at theloading rate of 0.5MPa/s and 1MPa/s respectively,under temperature of 500 ℃.By calculating the compressionratio and modulus,the corresponding compression resilience constitutive equation was fitted.The results showthat the compression modulus of the flexible graphite corrugated metal gaskets increases with the loading ratesincreasing.After the first compression,the compression modulu of the gasket changes a little but it is significantlyhigher than the initial compression modulus.The maximum compression of the gasket increases with theincrease of cycle number,which shows a significant effect of the ratchet wheel.The ratchet deformation ofgaskets should be considered to ensure the tightness of bolted-flange joints.And according to the fittedcoefficient,the compression resilience performance of this type of corrugated composite gasket can be inferred atdifferent loading rates.