A representative volume element method and a novel mesomechanical-based polyline model are proposed to describe the misalignment of in-plane fibers induced by the insertion of stitch thread.A multi-scale mathematical ...A representative volume element method and a novel mesomechanical-based polyline model are proposed to describe the misalignment of in-plane fibers induced by the insertion of stitch thread.A multi-scale mathematical model of in-plane elastic parameters for stitched composite laminate is established with ply-angle and stitch parameters as well as material parameters taken into account.Based on the fabrication of specimens and the verification of experimental platform,the superposition influences of stitch on structural anisotropy are revealed by the developed theoretical model.Results indicate that the stitch orientation can increase the structural anisotropy.The decreases of stitch pitch and spacing as well as the increase of thread diameter obviously reduce the elastic and shear moduli of laminates.Furthermore,the elastic and shear moduli as well as Poisson’s ratios show sinusoidal changes with a period of 90°as the ply-angle increases.The theoretical model not only analyzes the in-plane mechanical properties of stitched laminate with ply-angle,but also lays a foundation for the dynamic studies of stitched sandwich structures with ribs in the future.展开更多
Tension and shear tests are carried out on composite cross-joints, produced by resin transfer moulding (RTM), stitch-RTM and cobonding techniques separately, to investigate the influences of different production metho...Tension and shear tests are carried out on composite cross-joints, produced by resin transfer moulding (RTM), stitch-RTM and cobonding techniques separately, to investigate the influences of different production methods on their mechanical properties and their failure mechanism. It is concluded from test results that, in terms of mechanical properties, the RTM-made cross-joint holds superiority over other two, and both stitch-RTM and cobonding methods have significant adverse effects on mechanical proper- t...展开更多
基金National Natural Science Foundation of China(No.52075280)Natural Science Foundation of Shandong province(No.ZR2019MEE088)。
文摘A representative volume element method and a novel mesomechanical-based polyline model are proposed to describe the misalignment of in-plane fibers induced by the insertion of stitch thread.A multi-scale mathematical model of in-plane elastic parameters for stitched composite laminate is established with ply-angle and stitch parameters as well as material parameters taken into account.Based on the fabrication of specimens and the verification of experimental platform,the superposition influences of stitch on structural anisotropy are revealed by the developed theoretical model.Results indicate that the stitch orientation can increase the structural anisotropy.The decreases of stitch pitch and spacing as well as the increase of thread diameter obviously reduce the elastic and shear moduli of laminates.Furthermore,the elastic and shear moduli as well as Poisson’s ratios show sinusoidal changes with a period of 90°as the ply-angle increases.The theoretical model not only analyzes the in-plane mechanical properties of stitched laminate with ply-angle,but also lays a foundation for the dynamic studies of stitched sandwich structures with ribs in the future.
文摘Tension and shear tests are carried out on composite cross-joints, produced by resin transfer moulding (RTM), stitch-RTM and cobonding techniques separately, to investigate the influences of different production methods on their mechanical properties and their failure mechanism. It is concluded from test results that, in terms of mechanical properties, the RTM-made cross-joint holds superiority over other two, and both stitch-RTM and cobonding methods have significant adverse effects on mechanical proper- t...
