Analysis and Prediction of Woven Fabric Composites Properties

• Main Authors: Chang Ting Lin, 林昌鼎
• Other Authors: Kun Hsieh Tsai
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/42752808490952557736

碩士 === 逢甲大學 === 紡織工程學系 === 87 === The spring model is incorporated in the Finite Element Method (FEM) to predict the elastic moduli of the fabric composite materials. This analysis method considers the crimp arrangement of the fiber tows and the interaction among all fiber tows in the unit cell. Each fiber tow is treated as a spring curve with the same rigidity as the fiber tow itself along the fiber tow direction. The simulated spring embedded in the matrix of the unit cell is then discretized into many small sections. The matrix is also discretized using adequate FEM mesh requiring the nodal points coinciding with the end points of all the spring sections. The force equilibrium equations are derived using minimum potential energy theorem. By assigning proper displacement boundary conditions of unit strain deformation the average stresses in the unit cell are calculated, and the homogenized composite properties of the unit cell are also obtained. Primarily, the effects of fiber volume fraction and the high/length (H/L) ratio of the unit cell on the elastic’s moduli of woven composites were analyzed. The results show that the Young’s and shear moduli increase with increasing fiber volume fraction for a constant H/L ratio. On the other hand, for a constant fiber volume fraction, the Young’s moduli decreases and G23 and G13 increase with increasing H/L ratio. Furthermore, the relative shift of the neighboring laminae is observed to have very limited effect on the moduli of the woven laminate. Also the weaving architecture yields hardly any influence on the moduli of the satin fabric composites. As for the comparison of the moduli among those three different fabric composites, the following results are obtained: (1) the satin fabric composite has the highest value of E11, E22,ν12; (2) the plain weave fabric composite has the highest value of ν13, ν32, G13, G23; (3) the values of G12 are the same for those different fabric composites.