Longitudinal Elastic Modulus Prediction of a 2-D Braided Fiber Composite

Abstract

An analytical model based on classical laminate plate theory (CLPT) was developed to predict the longitudinal elastic modulus of a 2-D braided fiber composite. A sinusoidal function was used to model the path of undulating strands. This work represents a generalization of the plain weave case as the angle between the strands is not restricted to 90°. The results predicted by the model are in good agreement with other models and are in excellent agreement with experimental results for braided Kevlar 49/epoxy resin tubes. The predicted and experimental results confirmed that the longitudinal elastic modulus of a braided tube is less than that of one composed of laminated layers.

Micro-computed tomography analysis of tubular braided composites

“…To simplify and automate the braid strand identification and measurement process, a cylinder unwrapping algorithm has been developed to convert the original tubular braid lCT images into a flattened braid structure. This study will provide a new method for accurately assessing braid strand path geometry and voids content measurements that are necessary for accurate prediction of tubular composite braid material properties and modeling [5,6].…”

“…Similar to composite laminates, the mechanical properties of tubular braided composites can be predicted using the braid geometry and with the mechanical properties of the composite constituents [5,6]. Accurate knowledge of the matrix and fiber volume fractions is required for these mechanical models.…”

“…Composite braid geometries were initially modeled using the mosaic model of Ishikawa and Chou [7] and the fiber undulation model of Naik and Shembekar [8]. Recently, braid strand path has been modeled by assuming fibers follow a sinusoidal path [6,9,10]; however, these models do not account for variations that may occur during composite braid manufacturing. To assess the accuracy of these models, it is necessary to develop a technique is necessary to evaluate the accuracy and consistency of tubular braids manufactured using a Maypole braider.…”

A modified micromechanical curved beam analytical model to predict the tension modulus of 2D plain weave fabric composites

“…Fewer geometry characteristic parameters of warp and weft yarns and the elastic moduli of fibre and resin are required to predict tension modulus of PWF composites than with other models given in the literature [5,[14][15][16][17][18][19][20][21][22][23][24][25][26][27].…”

“…Naik et al [5,17,18] considered the fibre undulations in two orthogonal directions and used more detailed trigonometric functions to extend the crimp models of Ishikawa and Chou (i.e., two-dimensional undulation parallel-series and series-parallel models) to evaluate different elastic properties of PWF composites. Saka and Harding [19] and Carey et al [20] developed rectilinear and sinusoidal crimp models to predict elastic properties by means of classical laminate plate theory applied in the context of an elastic foundation and using the principle of equivalent strain energy. Tong et al [21] assumed the fibre as a curved beam supported by an elastic tension or shear foundation in a woven composite material and presented a curved beam model to investigate the effect of fibre yarn waviness on the tensile strength of woven composite materials based on the classical laminate plate theory.…”