螺栓与孔间隙对单搭单螺栓连接板模态频率的影响

由于装配需要或者制造误差等因素的影响,连接板的螺栓与螺栓孔之间不可避免地存在间隙,而且间隙的变化对连接板的模态频率有一定的影响。通过研究螺栓与孔间隙对单搭单螺栓连接板模态频率的影响机制,讨论一种基于变通孔直径的螺栓连接动力学设计方法。首先,基于ABAQUS软件和Python语言,建立了包含变通孔直径的单搭单螺栓连接板有限元计算模型;然后,探讨了螺栓连接板在一端固支、两端固支两种边界条件下螺栓与孔间隙变化对连接板模态频率的影响机制;最后,提出了一种基于变通孔直径的螺栓连接板动力学设计方法。结果表明:当通孔直径为螺栓直径的1.02~1.20倍时,通孔直径的变化对螺栓连接板各阶固有频率的影响可忽略;通孔直径大于螺栓直径的1.21倍时,其变化对连接板模态频率有明显的影响,且影响程度各异。研究表明在特定激励环境下可通过改变通孔直径来改变系统模态频率,从而避免结构共振。该方法为螺栓与孔间隙对复杂螺栓连接系统固有频率的影响分析提供了参考,也为螺栓连接系统的抗振疲劳设计问题提供了思路。

Impact of bolt-hole clearance on modal frequency of single lapped and single bolted joint plate

It is inevitable that there is clearance between the bolt and the hole of bolted joint plate on account of the need of assemble and manufacture errors .And the changes of clearance have some influence on the modal frequencies of the bolted joint plate .The influence mechanisms of bolt-hole clearance on the modal frequencies of a single lapped and single bolted joint plate system were investigated ,and subsequently a dynamical design method for bolted joint plate system by changing the diameter of through-hole was proposed .Firstly ,the finite element modeling method was proposed by using ABAQUS package and Python language .Thereafter ,a dynamic finite ele-ment model of the bolted joint plate system with variable diameter of through-hole was set up . Then the relation of the bolt-hole clearance and the modal frequencies of bolted joint plate was an-alyzed in two kinds of boundary conditions ,including one end fixed and both ends fixed .Under a typical vibrating frequency band ,the dynamic design method of the bolted joint plate system by changing the diameter of through-hole was discussed in the end .Results indicated that when the diameter of the through-hole was 1 .021 .20 times of the bolt diameter ,the influences of bolt-hole clearance on the modal frequencies of bolted joint plate could be negligible .However ,when the diameter of through-hole was larger than 1 .21 times of bolt diameter ,the effects of bolt-hole clearance on the vibration modal frequencies were obvious and the modal frequencies were muta-tion .The research shows that the modal frequency of system can be changed by changing the bolt-hole clearance in the specific incentive environment ,so as to avoid the structure resonance . The proposed method provides some reference for analyzing the influence of bolt-hole clearance on natural frequency of complex bolted joint system ,and also provides an idea of anti-vibration fatigue design method for the bolted joint system .