螺栓结合面法向接触刚度不确定性量化

Uncertainty quantification of normal contact stiffness of bolt joint surface

螺栓结合面接触中存在诸多不确定性因素,现有模型难以确定接触刚度的合理区间,为此,应用区间估计理论以获得微观形貌不确定的结合面接触刚度变化范围。首先,基于分形理论表征结合面微凸体轮廓高度,采用结构函数法和区间算法求解结合面分形参数不确定性区间;然后,通过矩谱法将表面形貌参数与分形参数并联,并引入切比雪夫包络函数计算出不确定性因素影响下的表面形貌参数区间;最后,将形貌参数不确定区间引入统计模型,建立考虑表面形貌参数不确定的结合面接触刚度模型,获得结合面接触刚度的区间,并探究了表面形貌参数对结合面接触刚度的影响。结果表明:该模型能准确预测螺栓结合面接触刚度的变化范围,可为结合面的设计提供指导。

There are many uncertainties in the contact of bolted joints.It is difficult to determine the reasonable interval of contact stiffness in existing models.Therefore,the range of contact stiffness of joint surface with uncertain micromorphology is obtained by using interval Estimation theory.Firstly,based on fractal theory to characterize the contour height of the micro-convex body of the combined surface,the structural function method and interval algorithm are used to solve the uncertainty interval of the fractal parameters of the combined surface.Then,the surface topography parameters are connected in parallel with the fractal parameters by moment spectroscopy.The Chebyshev envelope function is introduced to calculate the surface morphology parameters interval under the influence of uncertainty.Finally,the uncertainty interval of surface morphology parameters is introduced into the statistical model to establish the contact stiffness model of joint surface considering the uncertainty of surface morphology parameters.The range of joint surface contact stiffness is obtained,and the influence of surface morphology parameters on the joint surface contact stiffness is explored.The results indicate that the model can accurately predict the range of changes in the surface contact stiffness of bolted connections,which can provide guidance for the design of the joint surface.