Constitutive Prediction Model Of 3D Woven Resin-based Composite Material

Three dimensionally(3D)woven carbon fiber reinforced resin based composite material has widely been applied in aerospace industry particularly in aircraft engine's cold section.One-piece 3D woven composite fan can significantly improve the whole engine performance.As the vital basis of one-piece 3D woven composite fan,much effort has been spend on 3D woven composite variable –thickness plate fabric preform manufacture while geometry structure and mechanical properties of the composite variable –thickness plate are urgently desired,which is the main issue of this paper.The main objectives of this paper have been listed below:(1)The warp-direction and weft-direction tensile experiments of 3D woven plate specimen with different width from 20 mm to 40 mm at the interval of 5mm have been conducted in this paper to discuss the trimming effect of the specimen width.The obtained experimental results provide a reference to determine the tensile specimen size while test standards are nowadays unavailable.(2)The size of weft yarn,one of the significant weaving processing parameters,has been changed to gain different constant thickness 3D woven plates and to design variable-thickness 3D woven plates.In this paper,three constant thickness plates with different weft yarn size and two variable-thickness plates have been tested to discuss the influence of weft yarn's size change to warp direction moduli.(3)Based on the optical detection results of the actual structure of constant thickness and variable-thickness plates,a cell geometry model to predict the inner architecture of constant thickness and variable-thickness 3D woven plate in general has been presented in this paper.The cases comparing the key measurements of yarns from optical detection and predicted results validate the proposed model.Meanwhile,the expected thickness and the observed value of the variable thickness plate in the position of different weft rows fit well,which means the cell geometry model can also be utilized to guide the design of variable-thickness plate.(4)A cell stiffness model has also been investigated on the basis of the cell geometry model with the help of commercial finite element simulation software to predict the moduli,which has been verified through the good agreements between the expected value and related test results of the constant thickness and variable-thickness plate cell finite model.Another two cases have also been studied.In these cases,the predicted value from cell stiffness model was imported to two macro-scale plate finte models,intact plate finite model and trimmed plate finite model,to get the stiffness at different position.The comparison between the expected value and test results furtherly demonstrates the rationality of the proposed cell stiffness model.