Xie Fang, Chen Ju, Yu Qian-Qian, Dong Xinlong
Faculty of Mechanical Engineering & Mechanics, Ningbo University, Ningbo 315211, China.
Department of Civil Engineering, Shaoxing University, Shaoxing 312000, China.
Materials (Basel). 2019 Jul 16;12(14):2280. doi: 10.3390/ma12142280.
Fiber-reinforced polymer (FRP) materials nowadays have attracted much attention in both retrofitting of aged infrastructure and developing of new structural systems attributed to the outstanding mechanical properties. Extensive studies have been performed on concrete-filled glass FRP (GFRP) tubes for the potential application in piling, poles, highways overhead sign structures and bridge components. The new hybrid member also provides an alternative solution for traditional transmission structures. However, the connection between concrete-filled GFRP tubes and cross arms has not been fully understood. In this paper, an experimental study and theoretical analysis were conducted on the behavior of cross arms inserted in concrete-filled circular GFRP tubular columns. Steel bars with a larger stiffness in comparison with GFRP tubes were selected here for the cross arm to simulate a more severe scenario. The structural responses of the system when the cross arms were subjected to concentrated loads were carefully recorded. Experimental results showed that the concrete-filled GFRP tubes could offer a sufficient restraint to the deformation of the cross arm. No visible cracks were found on the GFRP tube at the corner of the cross arm where the stress and strain concentrated. Theoretical solutions based on available theories and equations were adopted to predict the displacement of the cross arms and a good agreement was achieved between the prediction results and experimental findings.
如今，纤维增强聚合物（FRP）材料因其出色的力学性能，在既有基础设施改造和新型结构体系开发方面都备受关注。针对玻璃纤维增强聚合物（GFRP）管内填充混凝土在打桩、电线杆、公路高架标志结构及桥梁部件中的潜在应用，已开展了大量研究。这种新型混合构件也为传统输电结构提供了一种替代解决方案。然而，GFRP管内填充混凝土与横臂之间的连接尚未得到充分理解。本文对插入圆形GFRP管内填充混凝土柱中的横臂性能进行了试验研究和理论分析。此处选择了与GFRP管相比刚度更大的钢筋用于横臂，以模拟更恶劣的工况。仔细记录了横臂承受集中荷载时系统的结构响应。试验结果表明，GFRP管内填充混凝土能够对横臂的变形提供足够的约束。在横臂拐角处应力和应变集中的GFRP管上未发现明显裂缝。采用基于现有理论和方程的理论解来预测横臂的位移，预测结果与试验结果吻合良好。
