Z-pins增强层合梁后屈曲分层扩展数值模拟研究

NUMERICAL ANALYSIS OF DELAMINATED BEAM THROUGH-THICKNESS REINFORCED BY Z-PINS

分层损伤是层合复合材料结构的一种最主要的损伤形式,层合板内一旦存在分层损伤,这些分层就会在较低的面内压缩应变下发生失稳和扩展,从而引起结构失效,因此必须采取有效的措施来抑制分层的产生和扩展.目前,一种方法是在层合板内沿厚度方向嵌入Z-pins,以提高其较弱的层间断裂韧性.论文采用考虑一阶剪切的梁单元,结合Z-pins增强体单元,建立了Z-pins横向增强的含对称穿透分层的复合材料层合梁有限元模型,利用数值模拟分析了含分层的层合梁在压缩载荷作用下发生对称失稳时,Z-pins增强体对分层扩展的抑制作用,为进一步的实验研究做出预测.结果表明,复合材料层合梁在对称失稳的情况下,Z-pins增强体能够有效地抑制分层的扩展.

Delamination is a major damage occurring in the laminated composite structures due to its weak interlaminar properties.The delamination may propagate at a low in-plane compressive strain,which results in structural failure.Consequently,it is necessary to improve the delamination toughness to retard its imitation and propagation.With through-thickness Z-pins insertion,the delamination toughness of Zpinned laminates can be improved significantly.In this paper,a finite element model of through-width symmetrically delaminated composite beam reinforced by Z-pins was proposed by using beam element with shear effect and Z-pin element.The delaminated composite beam was assumed to buckle in a symmetrical mode under in-plane compression.Numerical analysis was carried out to demonstrate the enhancement of Zpins in delamination propagation.Numerical results showed that Z-pins can effectively improve the in-plane compressive strain of delaminated composite beam.