Experimental and numerical study on the dynamic behavior of concrete-filled double steel tubular T-joint under impact loading. (1st February 2023) - Yan, Qingfeng
Abstract: This study investigates the performance of T-joints in the jacket foundation of offshore wind turbines under impact loading by means of experimental and simulation analysis. The deformation pattern and dynamic response of one hollow T-joint and eight concrete-filled double steel tubular T-joints (CFDST T-joints) are explored through a pendulum testing machine. The experimental results indicate that the local indentation dominates in the deformation process of hollow T-joint while the failure mode of CFDST T-joint will be commonly the global bending. The impact force-displacement curves corresponding to different parameters have similar tendencies and each curve can be divided into four stages. Increasing the impact velocity and axial compression ratio can reduce impact resistance. Meanwhile, increasing outer tube thickness and changing hollow rate exert a remarkable effect on the dynamic performance. Finite element models are then proposed to validate the experimental results and investigate the energy dissipation mechanism of T-joints under impact loading. The plastic deformation of the outer tube is the main energy dissipation mechanism for CFDST T-joints. In general, the investigation in this study offers a reliable basis for the study of impact failure mechanism for CFDST T-joint. Highlights: A pendulum machine was used to investigate the dynamic response of CFDST T-joints and hollow T-joints. CFDST T-joint exhibited negligible local indentation compared to hollow T-joint. High axial compression ratio and large impact velocity increased the deformation of CFDST T-joints. 0.63 is the optimal hollow rate within the parameter range of this study. The plastic deformation of the outer tube is the main energy dissipation mechanism for CFDST T-joints.