基于多轴向铺层设计的FRP拉挤方管螺栓节点抗拉性能研究  

Investigation on the tensile performance of pultruded FRP square tube bolted joints based on multi-axial layer design

作　　者：林敬辉 张垒志 汪昕[2,3] 刘霞[2,3] 严宗雪 李达 周杰[2,3] LIN Jinghui;ZHANG Leizhi;WANG Xin;LIU Xia;YAN Zongxue;LI Da;ZHOU Jie(Guangzhou Highway Engineering Group Limited Company,Guangzhou 510075,China;Key Laboratory of Concrete and Prestressed Concrete Structures,Ministry of Education,Southeast University,Nanjing 211189,China;National and Local Joint Engineering Research Center for Basalt Fiber Production and Application Technology at Southeast University,Nanjing 211189,China)

机构地区：[1]广州公路工程集团有限公司,广州510075 [2]东南大学混凝土及预应力混凝土结构教育部重点实验室,南京211189 [3]东南大学玄武岩纤维生产及应用技术国家地方联合工程研究中心,南京211189

出　　处：《复合材料科学与工程》2025年第1期124-132,共9页Composites Science and Engineering

基　　金：国家自然科学基金(51878149)。

摘　　要：在基于构件-节点一体化设计优化出的多轴向铺层基础上,进一步探究了铺层(单轴向铺层UD、多轴向铺层MD1、单轴向和多轴向相邻铺层MD2及多轴向中混碳铺层BC)以及几何尺寸(端距和排距)对FRP拉挤方管螺栓节点抗拉性能的影响。试验结果表明,多轴向布(MD1和MD2)的加入使节点极限承载力提升50%以上,极限位移增大至2倍以上,极大改善了节点承载和节点延性。采用MD2铺层能够获得最大节点承载力;BC铺层没有提升节点承载力但使节点刚度增大了7%~30%。端距和排距对UD方管螺栓节点的破坏模式无明显影响,均呈现剪切或劈裂破坏模式。当端径比增加至4时,多轴向方管螺栓节点破坏模式开始或完全转变为延性挤压破坏;随着排距的增大,两孔共同挤压受力过程延长,实现了更高延性、更高承载力的节点性能。建议多轴向BFRP拉挤方管螺栓节点的端径比和排径比取为4以上。Based on the optimized multi-axial lay up with regard to the integral structural performance of FRP laminates and bolted joints,this paper further investigated the effects of lay up(uni-axial lay up UD,multi-axial lay up MD1,adjacent uni-axial and multi-axial lay up MD2 and adding carbon fiber into multi-axial lay up BC)and geometric parameters(end distance and pitch)on the axial tensile behavior of pultruded FRP square tube bolted joints.The experimental results reveal that adding multi-axial fabrics(MD1 and MD2)significantly enhances the joint ultimate capacity by over 50%and improved the ultimate displacement to more than twice the UD displacement,which greatly improves the ultimate capacity and ductility of FRP tube bolted joints.MD2 bolted joint exhibits the highest ultimate capacity,while the utilization of BC don’t improve the joint ultimate capacity but increase the joint stiffness by 7%~30%.The UD bolted joints consistently exhibit shear or splitting failure modes regardless of joint geometric parameters.When the end distance-to-bolt diameter ratio reaches 4,the failure modes of multi-axial tube bolted joint begin to shift or totally transitioned to ductile bearing failure.The simultaneous bearing process of two bolts is extended with increasing pitch,resulting in the enhancement of joint ductility and ultimate capacity.It is recommended to set the end distance-to-bolt diameter ratio and pitch-to-bolt diameter ratio of the multi-axial pultruded BFRP tube bolted joint to be no less than 4 in design.

关 键 词：FRP拉挤方管节点 多轴向铺层 端径比 排径比 抗拉性能 

分 类 号：TB332[一般工业技术—材料科学与工程]