拼装式复合材料圆管接头弯曲性能试验研究  

Experimental study on the bending performance of assembled joints for composite circular tubes

作　　者：袁帅 张冬冬 段金辉 高一峰 张芸强 莫昌金 YUAN Shuai;ZHANG Dongdong;DUAN Jinhui;GAO Yifeng;ZHANG Yunqiang;MO Changjin(College of Mechanics and Engineering Science,Hohai University,Nanjing 211100,China;College of Field Engineering,Army Engineering University of PLA,Nanjing 210007,China)

机构地区：[1]河海大学力学与工程科学学院,南京211100 [2]中国人民解放军陆军工程大学野战工程学院,南京210007

出　　处：《复合材料科学与工程》2025年第3期1-6,29,共7页Composites Science and Engineering

基　　金：国家自然科学基金(52278230);江苏省自然科学基金(BK20221531)。

摘　　要：为了实现纤维复合材料轻量化应急人行桥的现场快速拼装与构筑,本文基于复合材料预紧力齿连接和金属管螺纹设计了一种拼装式复合材料圆管接头,开展了两种具有不同局部构造接头的四点弯曲试验,对比和分析了破坏模式和极限承载力等力学行为。结果表明:拼装式复合材料圆管接头具有快速拼装构造特点和较高弯曲承载能力,适用于复合材料管梁构型应急人行桥。当拼装式圆管接头承受弯曲荷载时,若预紧力齿连接的金属外套不设置倒角,会造成复合材料管局部横向剪切破坏及初始损伤,随之造成纤维在管体上侧压缩和下侧拉伸下提前纵向破断,相邻复合材料管体发生典型的弯曲分层破坏。但当开设倒角时,异质材料管体相应交界处未发生明显的复合材料管体局部横向剪切破坏,呈现出典型的复合材料管弯曲破坏特征。与预紧力齿连接承受轴向荷载情况不同,受弯曲荷载时,需对其金属外套端部倒角进行优化设计,不仅可有效地改善拼装式复合材料圆管接头的破坏模式,而且可使接头弯曲承载力提升约15%。To enable the rapid on-site assembly and construction of lightweight fiber reinforced polymer(FRP)emergency footbridge,an assembled composite tubular joint that incorporates pre-tightened toothed connection(PTTC)and metal tube threads was proposed.Four-point bending tests were conducted on two types of specimens with different local structures to compare and analyze their mechanical behaviors,such as failure modes and ultimate load-bearing capacities.The results indicate that the proposed assembled composite tubular joint not only facilitates rapid assembly but also exhibits high flexural behavior,making it suitable for composite tubular beam configuration in emergency footbridges.When the assembled joint was subjected to bending loads,the absence of a chamfer on the metal sleeve of the PTTC led to localized transverse shear failure and initial damage to the composite tube.Thereafter,compression and tension stresses were induced on the upper and lower side of the composite tube,respectively,resulting in premature longitudinal fiber failure.Adjacent composite tubes experienced typical bending-induced delamination.However,when a chamfer was introduced,there was no obvious local transverse shear failure of the composite tube at the corresponding junction of the dissimilar materials,which shows typical bending failure characteristics.Unlike with axial loading,when the joints are subjected to bending loads,optimizing the chamfer design at the metal sleeve's end is crucial.This optimization not only improves the failure mode of the assembled composite tubular joint but also enhances its bearing capacity by approximately 15%.

关 键 词：纤维增强复合材料 应急人行桥 拼装式结构 圆管连接 预紧力齿连接 抗弯性能 

分 类 号：TB332[一般工业技术—材料科学与工程]