【作者】 尚德广； 郭振坤； 陶志强； 陈宏；

【Author】 De-Guang Shang;Zhen-Kun Guo;Zhi-Qiang Tao;Hong Chen;College of Mechanical Engineering and Applied Electronics Technology,Beijing University of Technology;

【机构】 北京工业大学机电学院；

【摘要】 本文从工程应用角度出发,采取试验与理论相结合的方法,开发了变幅多轴蠕变-疲劳寿命预测系统,提出一种谱载下低周多轴蠕变-疲劳寿命评估方法。从预测准确且便于工程应用的角度考虑,分析了现有多种不包含经验系数的多轴疲劳寿命预测模型,并通过试验数据评估这些模型的预测效果,确定适用于变幅多轴疲劳寿命预测的方法。依据所确定的寿命预测模型,结合变幅载荷多轴计数方法等理论,基于C++开发出高温变幅蠕变-疲劳寿命预测系统,并通过试验数据验证了系统寿命预测的效果。通过理论和试验研究,提出一种高温多轴谱载下低周蠕变-疲劳寿命评估方法,该方法可以考虑加载形式、载荷保持等影响。通过试验验证,该方法可以得到较好的预测效果。更多还原

【Abstract】 In this paper,fatigue and creep-fatigue life prediction methods are assessed under mutiaxial variable amplitude loading.Based on the assessment results,a fatigue and creep-fatigue life prediction software system is developed,and a method for creep-fatigue life prediction is proposed.Firstly,models for multiaxial fatigue life prediction are discussed.These models don’t contain any empirical coefficient,which are suitable for engineering application.Secondly,the methods for multiaxial creep-fatigue life evaluation were discussed.The methods are,namely,the time-life fraction method,the time-life fraction method that takes creep-fatigue interaction,and multiaxial strain-range partitioning method.The prediction results were compared with experimental data.Then the acceptable methods for the software were determined.Thirdly,based on the previous work and the theory of multiaxial cycle counting method,software for multiaxial creep-fatigue life evaluation under variable amplitude loading is developed.The software is based on C++ programming,and was evaluated by experiments.Finally,according to theoretical and experimental analysis,a method for multiaxial creep-fatigue life prediction under spectrum loading was proposed.The proposed method could take the variation of loading forms and the holding of loadings into consideration.A good agreement with the experimental results was attained by the proposed method.更多还原