Mechanical Modeling And Failure Analysis Of Bolted Composite Laminates

Carbon fiber reinforced composite materials have been widely used in various engineering fields because of their high strength and designability.In practical engineering applications,the bolted connection is a mechanical connection of a detachable and replaceable.Therefore,in the bolting condition of composite materials,the research on its mechanical properties has become the subject of many scholars.For the composite laminates with bolted working conditions,this subject studied the stress distribution around the bolt holes and the failure of the laminates.1.In the stress analysis process,considering the stress concentration around the hole,the composite functions proposed by A.L is used for calculation,these functions are specifically used to calculate the stress of the laminate within the bolted connection.Using these functions,stress calculations were performed on composite laminates of different geometries over the elastic range.Subsequently,the composite laminates were subjected to failure determination based on the Thai-Wu failure criterion in the finite element software ABAQUS.Obtain the stress distribution state of the edge of the laminate before the initial failure occurs.The finite element calculation results are compared with the analytical solutions,and good consistency is obtained.The calculation results were used to analyze the effect of different geometries on the stress distribution of the laminate.The position of the initial failure of the laminate is predicted by analyzing the stress distribution at the hole edge.2.The failure analysis process was performed in a finite element,and the composite material is subjected to progressive failure analysis.Combined with Helius:PFA,the failure judgment of composite laminates based on MCT failure criterion.Through this analysis process,the evolution process of laminates of different geometries from initial state to final failure is obtained.Since the sensitivity of different component of composite materials to load is different,a sub-region failure sensitivity analysis method is proposed to calculate the failure degree of different regions at the edge of the hole.The degree of different components combined with the stress concentration factor to calculate the failure sensitivity of the components in different regions.The failure diffusion direction can be obtained by comparing the degree of component failure with the degree of the laminate.By performing different configurations of nonlinear feature sets in ABAQUS,a more detailed division of the composite component failure degree is achieved.The resulting component degree of component failure is functionally related to the health of the laminate and the results are more visualized through multiple curves.