Analysis of rehabilitated steel pipes subjected to impact loading using finite element framework

![CDATA[FRP composite systems with their highly desirable structural properties have become increasingly popular in the past two decades. An application which has been quite challenging while interesting has been in the area of pipes rehabilitation /strengthening. Extension of the service life and avoiding demolition and rebuilding has been a major incentive. Similar to normal pipes, rehabilitated pipelines are under the threat of being subjected to impact loads such as rock falls, and impact of a projectile or a vehicle. The effect of such an impact on rehabilitated pipes needs investigation as it may more adversely affect rehabilitated pipes in comparison to intact pipes. As experimental work in this field is expensive and time consuming, often recourse is made to numerical methods in lieu of experiments; this study is a successful example of such approach. Hence, a finite element model is developed in ABAQUS for the evaluation of repaired pipes under impact/high rate loading. Six different repair scenarios with GFRP and CFRP laminates are considered for this study. First, the finite element approach is validated using experimental data in the literature. Then, using the validated finite element method, each repaired pipe is subjected to a high rate load and the results are compared with other pipes and also undamaged pipe. Results showed that the repaired pipes with higher laminate thickness performed acceptably with respect to absorbing the impact energy. CFRP laminates fared better than GFRP laminates under high rate loading. For regions that are in danger of intensive impact loads, the thickness of FRP laminates shall be chosen with care so that the impact energy can be mitigated.]]