Structural Behavior of Deficient Steel and Aluminum Tubular Members Retrofitted by CFRP Subjected to Impact Loading

Tubular structural members made of steel and aluminum are often prone to structural deficiencies, caused by corrosion and collisions with vehicles or ships, both onshore and offshore. As a result, these degraded members are highly susceptible to severe damage and can lead to the collapse of structures under transverse impact loads. Carbon fiber-reinforced polymer (CFRP) is one of the most promising composite materials for strengthening of aluminum and steel tubular structures. To address these concerns, CFRP has emerged as an attractive and effective solution for strengthening structurally deficient hollow section. The purpose of this study is to examine how CFRP composites strengthen metallic box sections under web impact stress in terms of their structural performance and demeanor. In order to use CFRP composites to strengthen metallic tube members under impact loads, significant test programs have been carried out. A total of twelve box components, eleven CFRP-strengthened members with varying lengths and orientations, and one non-strengthened reference member were tested in a drop hammer impact test system. When subjected to lateral impact loading with a velocity of 4–6.5 m/s, the research's findings offer insightful information. The findings showed that the deformation of mild steel, stainless steel, and aluminum tube sections was reduced by 30.23, 14.18, and 7.40%, respectively, when the box sections strengthened with CFRP were used. The findings show that use of CFRP strengthening enhances the impact resistance capacity of the tubular sections by decreasing side deformations up to 30.23% compared to unstrengthen aluminum tubular specimens. The application of CFRP strengthening is a useful technique for enhancing the performance of structurally flawed steel tubular members under impact loading, according to the experimental results.