Xu Jinyi, Ma Jian, Chen Yong, Cui Xu, Feng Bing, Mou Wending, Pan Feng
College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058, China.
China Energy Engineering Group Zhejiang Electric Power Design Institute Co., Ltd, Hangzhou, 310012, China.
Sci Rep. 2025 May 25;15(1):18276. doi: 10.1038/s41598-025-02929-5.
It is recognized that the semi-rigidity of the glass fiber reinforced polymer (GFRP) joint should be considered in the structural analysis of GFRP structures, because of the relatively small initial stiffness resulting from the intrinsic property of GFRP material. Regarding the integrally-formed GFRP T-joint in the GFRP transmission tower, the study of its semi-rigidity remains inadequate. This paper aims to develop the relevant method for approximating the initial stiffness of the integrally-formed GFRP T-joint, in which the joint connects a vertical column with circular hollow section (CHS) and a horizontal bracing beam with rectangle section (RS). The finite Element (FE) models are first established, and validated by comparing the FE analysis results with the experimental results extracted from the previous study by the authors. The parametric study is subsequently conducted by using the validated FE model to investigate the sensitivity of the initial stiffness to the joint's main geometrical parameters, i.e., the diameter and the thickness of the column, and the width and the height of the bracing beam. The total number of the specimens numerically modeled for the parametric study is 255. The mechanical model that reveals the main physical source of the initial stiffness is proposed. Based on the parametric analysis results, the approximating formula is then concluded, which is capable of well predicting the initial stiffness of the joint. The formula is first validated by comparing the theoretical results with the FE analysis results, considering the simply-supported T-shaped structures with/without the tapered haunches. Then, the GFRP line-suspension module (GFRP-LSM) utilized in a GFRP transmission tower is employed for further experimental validation. It is found that the structural analysis results, with consideration of the semi-rigidity of the joints, agree well the continuum shell element-based FE analysis results. In terms of the top displacement, the result obtained via the structural analysis is close to the measured data, indicating an error of 9.03%. In contrast, a significant discrepancy would be found when the semi-rigidity of the joints is neglected in the analysis, and the error would increase to 21.86%. The comparison again highlights the importance of considering the semi-rigidity of the GFRP joints in the structural analysis of a GFRP structure.
由于玻璃纤维增强聚合物（GFRP）材料的固有特性导致初始刚度相对较小，因此在GFRP结构的结构分析中应考虑GFRP接头的半刚性。对于GFRP输电塔中的整体成型GFRP T型接头，其半刚性的研究仍然不足。本文旨在开发一种近似整体成型GFRP T型接头初始刚度的相关方法，该接头连接圆形空心截面（CHS）的垂直柱和矩形截面（RS）的水平支撑梁。首先建立有限元（FE）模型，并通过将FE分析结果与作者先前研究中提取的实验结果进行比较来进行验证。随后，使用经过验证的FE模型进行参数研究，以研究初始刚度对接头主要几何参数的敏感性，即柱的直径和厚度以及支撑梁的宽度和高度。参数研究中数值模拟的试件总数为255个。提出了揭示初始刚度主要物理来源的力学模型。基于参数分析结果，得出了能够很好地预测接头初始刚度的近似公式。首先通过将理论结果与FE分析结果进行比较，考虑有无锥形加腋的简支T形结构，对该公式进行验证。然后，将GFRP输电塔中使用的GFRP线悬挂模块（GFRP-LSM）用于进一步的实验验证。结果发现，考虑接头半刚性的结构分析结果与基于连续壳单元的FE分析结果吻合良好。在顶部位移方面，通过结构分析获得的结果接近实测数据，误差为9.03%。相比之下，在分析中忽略接头的半刚性时会发现显著差异，误差将增加到21.86%。该比较再次凸显了在GFRP结构的结构分析中考虑GFRP接头半刚性的重要性。
