Study On The Influence Of Wrinkle Damage On Tensile Properties Of Composite Laminates

In order to investigate the influence of wrinkle aspect ratio,the number of wrinkle layers and the wrinkle deflection angles on the tensile properties of glass fiber / epoxy resin composite laminates,reference to ASTM D3039 was carried out to develop glass fiber composites without damage and containing different types of wrinkle defects for the tensile test of the material test piece,using the ABAQUS finite element software and combined with the progressive damage failure analysis method,the finite element analysis model of the test piece was established,and the tensile strength,stress concentration phenomenon and failure expansion mode of the model were simulated and analyzed.Finally,the test results are compared with the simulation analysis results to find out the effect of wrinkles on the tensile properties of the composite material.It provides a corresponding reference for the evaluation of the mechanical properties of composite materials with wrinkle defects.In the test results,the dispersion coefficient CV of the 11 sets of experimental data of the damage-free and three types of wrinkle defect test pieces are all less than 10%,which shows the effectiveness of the tensile test.The high agreement between the simulation analysis results and the test results shows that the analysis model can reveal the failure mechanism of the composite laminate with wrinkle defects under tensile load,and can finally predict the tensile strength;For the stress concentration phenomenon,the test pieces with different wrinkle height-to-width ratio,the stress concentration occurs at the wrinkling place of the second layer.For the test piece with different wrinkle layers,the stress concentration mainly occurs in the middle of the third layer of the test piece.For test pieces with different wrinkle deflection angles,stress concentration mainly occurs at both ends of the wrinkle-rich region.Three different types of wrinkle defects,the first failure of the fiber occurs at the stress concentration location,indicating that the stress concentration phenomenon in the wrinkle area is the leading factor that induces the early failure of the fiber layup;For the failure expansion analysis,the failure initiation of the test specimens with wrinkle defects occurs at the center of the wrinkled resin-rich region,mainly the tensile failure of the resin matrix,and gradually expands to the entire resin-rich region,as the tensile load increases,it expands to the failure of the fiber wrinkle.After the fiber layup fails completely,the test piece explodes;The effect of different wrinkle types on the tensile strength of composite test pieces is: as the increase of the wrinkle aspect ratio,the tensile strength of the laminate showed a decreasing trend.As the number of wrinkle layers increases,the tensile strength of the laminate significantly decreases.As the different wrinkle deflection angles decreases,the tensile strength of the laminate also decreases.