Analytical and experimental study of shape memory alloy reinforcement on the performance of butt-fusion welded joints in high-density polyethylene pipe

In this article, a shape memory alloy wire is employed as confinement to enhance the flexural rigidity of the butt-fusion welded joints in the high-density polyethylene pipes. To this end, analytical and experimental studies are considered, when the shape memory alloy wire is wrapped around a butt-fusion joint and an internal pressure is applied to the high-density polyethylene pipe. To investigate the efficiency of shape memory alloy wire jacket on the performance of butt-fusion welded joint in high-density polyethylene pipe, two cases of perfect butt-fusion joint and imperfect butt-fusion joint are tested. The influence of the number of shape memory alloy wire jacket on the high-density polyethylene pipe joints as well as the effect of different flexural rigidities of the wire and high-density polyethylene pipe, and different diameters are evaluated. The deformation is measured using linear voltage displacement transducer and digital image correlation analysis at different location of the pipe length. In addition, radial strain of the pipes due to bulging is measured by electronic resistance strain gauges. Results show that the shape memory alloy wire jacket has a significant effect (33%) on enhancing imperfect butt-fusion welded joint of high-density polyethylene pipes.