This paper aims to present an experimental investigation on the behavior of web-flange junctions (WFJs) rotational stiffness of pultruded fiber-reinforced polymer composites (FRP). Channels and I-sections were tested using a simple set-up, which was developed in order to experimentally characterize the junctions in a direct manner. The Digital Image Correlation (DIC) technique was used, allowing overall deflections and relative rotations between web and flange to be monitored. The WFJs' imperfections were analyzed through an optical microscope and correlated with the cracks' formation. Further, damage thresholds are identified using available stress equations for curved composite members and lower bound functions are proposed to simulate the junction stiffness retention. Finally, two Equations are developed in order to analytically predict pultruded junctions' rotational stiffness per unit of width. In general, the theoretical and experimental results agreed fairly well, with a maximum difference of 24% for I-sections and 38% for channels.

本文旨在对拉挤纤维增强聚合物复合材料 (FRP) 的腹板法兰接头 (WFJ) 旋转刚度的行为进行实验研究。通道和 I 型截面使用简单的设置进行测试，开发该设置是为了以直接的方式通过实验表征连接点。使用了数字图像相关 (DIC) 技术，可以监控腹板和法兰之间的整体偏转和相对旋转。WFJ 的缺陷通过光学显微镜进行分析，并与裂纹的形成相关联。此外，使用弯曲复合构件的可用应力方程确定损伤阈值，并提出下界函数来模拟连接刚度保持。最后，开发了两个方程以分析预测拉挤接头每单位宽度的旋转刚度。总的来说，理论和实验结果相当吻合，I 型截面最大差异为 24%，通道最大差异为 38%。