单向机织物增强复合材料层合梁弯曲破坏规律

Characterization on Flexural Failures of Unidirectional Woven Fabric Laminated Composites

五组单向机织物增强层合梁的弯曲实验表明:层合梁的最大弯曲强度通常并不对应于最后一层破坏时的荷载;铺设角不同的层合梁达到最大承载力时,破坏并不发生在同一层,且总的破坏层数和对应位移都不相同,其破坏形式可以定性预测.研究还表明:根据实测的单层板的非线性本构关系和强度指标,运用经典层合梁理论,可以对非弯扭耦合层合梁的最大承载力和挠度进行预测.

In this paper,bending failure experiments have been carried out for five groups of laminated beams reinforced with unidirectional woven fabrics.It has been indicated that the ultimate flexural strength of any of the laminated beams is not corresponding to its last ply failure load.Furthermore,failed lamination code and the total number of failed layers together with the critical deflection corresponding to the ultimate flexural load are different for a different laminate.The present paper also shows that based on the classical laminated beam theory and by using the nonlinear stress-strain relationship and ultimate strength parameters of the single layer which constituted the laminates,the flexural failure strength of the laminates could be reasonably estimated if the laminates were free of flexure-torsion coupling.