基于能量法的灰色GM(1,1)压力容器焊接结构寿命预测

摘要

Fatigue test is the best way to get the fatigue life data of welded structures,but it cannot be used frequently in the life prediction of welded structures because of its high cost and long time.Therefore,a fast and accurate fatigue prediction method is needed.Plastic strain energy theory is used to estimate welded structure of pressure vessel fatigue life,:and a grey GM (1,1) life prediction model is proposed based on the energy method to enhance estimation accuracy in low stress area.The fatigue life data comparison of the test and of that the model predicted shows it tends to an error rate less than 8 ％.Accurate and quick prediction can be obtained with the established mode,and the model is preferred to use in difficult operation including short of samples,incomplete information and lack of test conditions.%疲劳试验是得到焊接结构疲劳寿命的最佳方法,但其长耗时、高成本,无法频繁用于焊接结构的寿命预测中,因此需要一种快速准确的疲劳预测方法.应用能量寿命估算方法中塑性应变能理论,对压力容器焊接结构疲劳寿命进行估算.以能量法为基础构建灰色GM(1,1)寿命预测模型,提高低应力区估算准确率.对比疲劳寿命试验数据与模型预测的结果,误差率在8％以下.该模型能准确、快速预测压力容器焊接结构的疲劳寿命,尤其适合样本少、信息不完全及试验条件缺乏等工况下压力容器寿命的预测.