GFRP夹层结构螺栓连接的多参数分析

Multi-parameter Analysis of Bolt Connection of GFRP Sandwich Structure

针对升降舵前纵墙采用螺栓连接形式的PMI泡沫夹层GFRP结构进行了不同参数下的结构安全性分析。首先通过试验确定PMI泡沫与GFRP复合材料层合板的力学性能,并结合CCAR23部对气动载荷与惯性载荷的要求,对该结构在实际工况下的载荷进行了分析,确定其合适的螺栓预紧力和螺纹副摩擦系数;在此基础上结合装配配合公差(f7/H10),最终确定有限元计算的参数组合。然后根据PMI泡沫和GFRP层合板的力学性能特性,采用ABAQUS软件对PMI泡沫和GFRP复合材料层合板建立夹层结构螺栓连接有限元模型,并结合工况载荷、螺栓预紧力、摩擦系数和装配配合公差计算不同参数组合下结构的安全性。通过分析得到如下结论:(1)螺纹副接触摩擦系数的合理增加可有效减小夹层结构螺栓孔边应力集中,以增加结构的安全性;(2)螺栓与螺栓孔之间间隙的增加会增加孔边应力集中系数,造成结构的安全性减小;(3)在结构安全强度范围内,增加螺栓预紧力可以提高连接结构的连接疲劳强度和可靠性。

The safety of a polymethacrylimide(PMI)foam laminated glass fiber reinforced composite(GFRP)structure in the front longitudinal wall of an elevator is analysed through different parameters of bolt connection.Mechanical properties of PMI foam and GFRP laminates are studied experimentally and loads on the composite structure under actual working conditions are analyzed.Based on the analysis,an appropriate bolt pre-tightening force,thread friction coefficient,assembly tolerance,and different parameter combinations are determined for finite element calculation.A sandwich structure bolted finite element model is established using ABAQUS6.14 software,considering the mechanical properties of PMI foam and GFRP laminates,and the safety of the structure under different parameter combinations is calculated.The results show that an increase in the thread friction coefficient improves the stress concentration and structural safety,while an increase in the gap reduces the safety of the structure.Increasing the bolt pre-tightening force improves the connection fatigue strength and reliability of the connection structure.