摘要
选取Q235钢试样开展低周疲劳试验,通过改变加载幅值、加载频率等条件,研究分析了低周疲劳过程热力学熵产率与累积熵产变化特征。结果表明,熵产率随加载幅值的增大而升高且在同一载荷下熵产率近似恒定。低周疲劳过程中热力学熵的累积是一个准线性累加过程。试样最终疲劳断裂熵随加载幅值的增大而减小,与加载频率无明显关系。在此基础上建立了基于热力学熵的金属低周疲劳寿命预测模型,该模型可用于金属构件疲劳损伤的实时评估。
Q235 steel samples were selected to carry out low-cycle fatigue tests.The thermodynamic entropy generation rate and cumulative entropy production characteristics of low-cycle fatigue processes were analyzed under different loading conditions such as loading amplitude and loading frequency.Results show that the entropy generation rate increases with the increase of the loads and it is approximately constant under the same loads.The accumulation of thermodynamic entropy during low cycle fatigue is a quasi-linear accumulation process.The final FFE value of the material increases with the decrease of the load amplitudes,but has no obvious relationship with the loading frequency. Then,a low-cycle fatigue life prediction model was established based on thermodynamic entropy,which may be used in real-time evaluation of fatigue damages of metal component.
作者
朱达荣
徐德军
刘涛
汪方斌
储朱涛
ZHU Darong;XU Dejun;LIU Tao;WANG Fangbin;CHU Zhutao(School of Mechanical and Electrical Engineering,Anhui Jianzhu University,Hefei,230601;Key Laboratory of Construction Machinery Fault Diagnosis and Early Warning Technology of Anhui Jianzhu University,Hefei,230601)
出处
《中国机械工程》
EI
CAS
CSCD
北大核心
2019年第16期1904-1910,共7页
China Mechanical Engineering
基金
国家自然科学基金资助项目(51805003,61871002)
安徽省自然科学基金资助项目(1808085ME125)
安徽省高校自然科学研究项目(KJ2018A0519)
关键词
低周疲劳
损伤评估
热力学熵
熵产率
疲劳断裂熵
low cycle fatigue
damage assessment
thermodynamic entropy
entropy generation rate
fatigue fracture entropy(FFE)
