Study On Wrinkle Damage Of Glass Fiber Reinforced Composite For Fan Blade

Glass fiber reinforced composite is widely used in wind turbine blade manufacturing because of its high specific stiffness,high specific strength and insensitivity to fatigue.But the defects such as air bubble,wrinkle,delamination,resin-rich and poor wettability often appear in the forming process of the composite,compared with other common defects,wrinkling defects have a great influence on the properties of materials,such as compression resistance,tensile strength and fatigue life.The cost loss is defined as a key process characteristic parameter by many manufacturers.In this paper,based on the theoretical model of Tsai-Wu,finite element method and FORTRAN language and the subroutine USDFLD associated with the finite element commercial software ABAQUS.This paper focuses on tensile load strength degradation and gradual failure evolution study,and the accuracy of the simulation analysis is validated by experiment grouping design;studies further the three key features of wrinkle defects(wrinkle aspect ratio,the structure,the wrinkling of the laminated plates cloth offset Angle)on the tensile properties of glass fiber reinforced composite laminated plates.The main contents and conclusions of the study are as follows:(1)Tensile test and simulation were conducted for wrinkle-defect glass fiber reinforced composite laminates with basic uniaxial layered structure,Wrinkles of 90 °and different height-width ratios,and comprehensive analysis was conducted in combination with the tensile strength of non-destructive laminates.The results show that the ratio of height to width is inversely proportional to the tensile strength of composite laminates,and with the increase of ratio of height to width,the decrease of tensile strength of laminates increases gradually,therefore,it is necessary to consider the influence of wrinkle height when using height-to-width ratio to judge the quality of wrinkle.(2)Based on the actual engineering application,three basic braided types of glass fiber were selected to form seven laminated boards with different fabric layers for tensile tests,and combined with the tensile strength of non-destructive laminates,contrast tensile strength change.The results show that the tensile strength of the glass fiber reinforced composite laminates with uniaxial fabric is the largest,and the attenuation ratio affected by wrinkling is also the largest.The tensile strength of the glass fiber reinforced composite laminates with triaxial fabric is the strongest,and the tensile strength attenuation of the composite laminates with mixed structure shows a nonlinear trend.(3)Taking wrinkle migration angle as a variable,the tensile test and simulation study of glass fiber reinforced composite laminates were carried out,and the tensile strength of nondestructive laminates was comprehensively analyzed.The results show that the tensile load of laminates decreases first and then increases with the increase of wrinkle offset angle.There is a critical offset angle(the critical angle is determined to be between 45°and 60° through test and simulation analysis),and the tensile load of laminates is the minimum.(4)Based on the results of experiment and simulation,the failure analysis of composite laminates was carried out under the coupling of wrinkle height-width ratio,fabric structure and deflection angle of wrinkle,a method to predict the tensile property risk of composite products with wrinkling defects by drawing a risk assessment reference table is proposed.