呼吸性椭圆裂纹转子弯曲刚度模型

Bending stiffness model of a breathing elliptical cracked rotor

通常转子轴上的疲劳裂纹为椭圆形尖端,而国内外现有文献大多关注直裂纹转子,很少对椭圆裂纹呼吸行为建立模型。提出了新的圆柱轴椭圆裂纹呼吸模型,修正中性轴位置确定裂纹张开面积,并基于裂纹应变能计算出椭圆裂纹附加柔性系数,建立了该类裂纹转子弯曲刚度模型。进一步,与文献和有限元结果进行对比,裂纹呼吸规律完全符合,裂纹附加柔度、转子无量纲挠度满足计算要求,验证了该模型有效可行。

Usually a fatigue crack on a rotor shaft has an elliptical tip,while the current literatures at home and abroad mostly focus on straight-tip crack rotors,very few articles built models to study elliptical-tip crack breathing behavior.Here,a new breathing model of an elliptical crack on a cylindrical shaft was proposed to modify the neutral axis＇s position and determine crack open area.Based on the crack strain energy,the elliptical crack＇s additional flexibility coefficient was calculated,and the bending stiffness model of the elliptical cracked rotor was also established.It was shown that the proposed crack＇s breathing laws agree well with those of literatures and the finite element results,the crack＇s additional flexibility and rotor＇s dimensionless deflection both meet the requirements of computing,the effectiveness and feasibility of the model are validated.