基于薄层单元法的螺栓连接结构有限元模型确认

Finite Element Model Validation of Bolted Connection Structure Basing Thin Layer Element Method

由于螺栓连接结构结合面的粗糙度、预紧力矩和螺栓直径等因素具有不确定性,因此结合面的连接参数也是具有不确定性的,为了获得能描述连接参数不确定性的有限元模型,对螺栓连接结构开展有限元模型确认研究。将复杂的多螺栓结构拆分为简单的单个螺栓结构;先对单个螺栓结构做模型确认分析,采用薄层单元来表征结合面,通过模态试验数据修正获得薄层单元参数及其统计样本,对不确定性连接参数进行量化和传递分析,并采用模型确认准则验证该参数概率分布的合理性;再将考虑概率分布情况的单个螺栓结构的薄层单元参数应用到多个螺栓连接结构对其模态频率进行预测。研究结果表明:所采用的模型确认方法能量化薄层单元参数的不确定性,可建立具有一定可信度的螺栓连接结构有限元模型,由单个螺栓结构能预测多个螺栓结构的动力学特征。

Due to the uncertainty of the roughness,pre-tightening torque and bolt diameter of the joint surface of the bolted joint structure,the joint parameters of the joint surface are also uncertain.In order to obtain a finite element model that can describe the uncertainty of the connection parameters,model validation analysis was carried out on the bolted joint structure.The complex multi-bolt structure was divided into simple single bolt structure.First,the model validation was performed on single bolt structure.Thin layer elements were used to characterize the bonding surface.The parameter of the thin layer elements and their statistical samples were obtained by modal updating.Uncertainty connection parameter was quantified and transitively analyzed.The model validation criteria were used to verify the rationality of the probability distribution of the parameter.The thin layer elements parameter of single bolt structure considering the probability distribution was applied to multi-bolt structure to predict its modal frequency.The results show that the model validation method can quantify the uncertainty of thin layer elements parameter,and can establish the finite element model of bolted joint structure with certain credibility,the dynamic characteristics of multi-bolt structure can be predicted by single bolt structure.