基于玻纤映射的螺栓连接强度及损伤分析

BOLTED JOINTS CONNECTION STRENGTH & DAMAGE EVOLUTION ANALYSIS BASED ON FIBER MAPPING

探讨了车身结构中注塑成型玻纤增强复合材料(GFRP)螺栓连接强度及其损伤失效的主要类型。开展了PA6GF30材料的相关力学性能测试,基于Multicontinuum(MTC)理论进行材料分解与材料参数拟合,获得了有限元仿真分析的相关材料参数。拉伸样条的仿真与实验结果表明:基于材料分解、玻纤映射、材料参数拟合的仿真分析方法能有效解决注塑件模流分析与结构分析的延续性与准确性问题,同时提高了仿真分析的效率。基于玻纤材料的准确映射信息,着重研究了玻纤增强复合材料间螺栓的连接强度与损伤失效模式,并综合分析了端径比、宽径比及厚径比对螺栓连接强度及材料损伤失效的影响。结果表明:连接失效的主要模式为拉伸失效与挤压失效,且对连接性能影响较大的因素依次为宽径比、厚径比、端径比;随着宽径比、端径比的增大,螺栓的连接强度均有所增强,但当比值分别大于4和2.5后连接强度不再增加,主要表现为挤压失效;增大厚径比能显著提高螺栓的连接强度。

The main types of the bolt connection strength and the damage failure of the injection molding glass fiber reinforced composites（ GFRP） in the body structure have been studied. Mechanical properties tests of the PA6 GF30 materials have been carried out,based on Multicontinuum materials decomposition theory,fiber mapping and fitting materials curve to obtain their simulation parameters. Compared with the results of simulation and experiment,it showed that based on material decomposition,fiber mapping,curve fitting of the simulation analysis method,we can effectively solve the problems between moldflow analysis and structure analysis continuously and accurately.Based on the accurate mapping information of GFRP,the bolt connection strength and damage failure modes between GFRP were studied,and comprehensive studies of E/D,W/D and T/D on the strength of bolt connection were performed. The results show that the main forms of connection failure are tensile failure and extrusion failure,and the factors that affect the connection performance are W/D,T/D and E/D. With the increase of the E/D and the W/D,the bolt connection strength increases,but the ratio no longer increases after a certain number,which is mainly manifested as the extrusion failure. Increasing the T/D can significantly increase the bolt connection strength.