【作者】 马一江； 陈国平；

【Author】 MA Yijiang;CHEN Guoping;College of Mechanical Engineering,Nanjing University of Science and Technology;The State Key Laboratory of Mechanics and Control for Mechanical Structures,Nanjing University of Aeronautics and Astronautics;

【机构】 南京理工大学机械工程学院； 南京航空航天大学机械结构力学及控制国家重点实验室；

【摘要】 基于传递矩阵法和修正Paris公式,提出了一种在高温和轴向力作用下含多条裂纹合金钢梁的模态和疲劳寿命分析方法。在模态分析过程中,通过弹性模量引入温度模块;利用无质量的弯曲弹簧来等效裂纹段,基于传递矩阵方法推导出含有温度、轴向力和裂纹参数的传递矩阵;根据裂纹梁不同的边界条件,求解裂纹梁的固有频率,并与有限元方法求得的固有频率进行对比。在疲劳寿命分析过程中,通过复弹性模量引入阻尼损耗因子;基于修正Paris方程和同步分析法,分析了温度和轴向力对裂纹悬臂梁疲劳寿命的影响。结果表明:轴向力的增大使得裂纹梁第一阶固有频率逐渐增大,并且总体上逐渐提高裂纹梁的共振疲劳寿命;高温会显著降低裂纹梁的固有频率和疲劳寿命。更多还原

【Abstract】 Based on the transfer matrix method and the modified Paris formula, an analytical method is proposed to investigate the modal and fatigue life of the alloy steel beam with multiple cracks under high temperature and axial forces. In the modal analysis process, the temperature module was introduced through the elastic modulus; bending springs without mass were used to replace cracks, and the transfer matrix containing the temperature, axial forces and parameters of cracks was derived based on the transfer matrix method; natural frequencies of the cracked beam would be obtained by the application of different boundary conditions, and compared with results calculated by the finite element method. In the fatigue life analysis process, the damping loss factor was introduced through the complex elastic modulus; the influence of the temperature and axial forces on the fatigue life of the cracked cantilever beam was analyzed based on the modified Paris formula and timing analysis method. Results indicate: the increase of the axial force leads to the increase of the first order natural frequency, and gradually increases the resonant fatigue life of the cracked beam generally; high temperature can significantly reduce the natural frequency and fatigue life of the cracked beam.更多还原