Research On Damping Characteristics Of CFRP Single-lap Adhesive Joint

The design of joints is one of the most challenging tasks in the structural design of carbon fiber reinforced plastic(CFRP).As a transportation vehicle,rail transit trains inevitably face many dynamic problems during high-speed operation.The connecting part is a key part of the CFRP structures and its mechanical environment such as vibration and noise are very complicated.Improving the damping performance of the connecting part can effectively reduce its dynamic response.Therefore,it is significant to carry out research on the damping characteristics of CFRP single lap joints.This paper takes CFRP single-lap joint as the research object,and adopts a research method combining theoretical modeling,experiments and simulation analysis to study the influence of various parameters on the damping characteristics of CFRP single-lap joints.This paper mainly studies on the following aspects:Firstly,combined with the composite material laminated plate damping loss factor model and finite element analysis method,a CFRP single-lap joint damping prediction model based on modal strain energy method is proposed.The model of typical lay angle CFRP single lap joints was established in ABAQUS.The modal solution was carried out to obtain the natural frequency and the corresponding vibration mode.According to the proposed damping loss factor calculation model,the damping characteristics of the single lap joints was predicted.The vibration modal test of typical CFRP single lap joints was carried out.The test results agree well with the simulation results,which verifies the correctness of the model.Secondly,with the help of ABAQUS finite element analysis software,combined with the obtained CFRP single-lap joints damping prediction model,the damping characteristics of CFRP single-lap joints are studied.The parameters of the layup,the material properties of the adhesive,and the geometric dimensions of the bonding are compared to influence of damping characteristics of CFRP single-lap joints.Thirdly,CFRP single-lap joint test pieces with different parameters are prepared,and the modal analysis test is performed.The test results are compared with the results of finite element simulation analysis.The test results are in good agreement with the data obtained from the simulation analysis.The CFRP single-lap joints damping prediction model proposed in this paper is correct;and the test results can verify some conclusions of the influence of different parameters obtained by finite element numerical analysis on the damping characteristics of CFRP single-lap joints.