In-Plane Shear Strength of Single-Lap Co-Cured Joints of Self-Reinforced Polyethylene Composites

Abstract

The present study introduces the analysis of single-lap co-cured joints of thermoplastic self-reinforced composites made with reprocessed low-density polyethylene (LDPE) and reinforced by ultra-high-molecular-weight polyethylene (UHMWPE) fibers, along with a micromechanical analysis of its constituents. A set of optimal processing conditions for manufacturing these joints by hot-press is proposed through a design of experiment using the response surface method to maximize their in-plane shear strength by carrying tensile tests on co-cured tapes. Optimal processing conditions were found at 1 bar, 115 °C, and 300 s, yielding joints with 6.88 MPa of shear strength. The shear failure is generally preceded by multiple debonding-induced longitudinal cracks both inside and outside the joint due to accumulated transversal stress. This composite demonstrated to be an interesting structural material to be more widely applied in industry, possessing extremely elevated specific mechanical properties, progressive damage of co-cured joints (thus avoiding unannounced catastrophic failures) and ultimate recyclability.

Self‐reinforced polymer composites: An opportunity to recycle plastic wastes and their future trends

“…Camargo et al introduced single‐lap co‐cured joints of SR ‐ UHMWPE composites and studied its shear strength variation. The outcome of this study was that, a low superficial adhesion of UHMWPE was responsible for the non‐catastrophic debonding‐induced progressive damage of the joint through longitudinal cracks at higher joint lengths 75 …”

“…The outcome of this study was that, a low superficial adhesion of UHMWPE was responsible for the non-catastrophic debonding-induced progressive damage of the joint through longitudinal cracks at higher joint lengths. 75 Commonly, UHMWPE is used as reinforcing material, and HDPE or LDPE as matrix material. This is due to the fact that the UHMWPE has relatively much higher crystalline melting temperature compared to the HDPE and LDPE, hence the processing of SR -PE is relatively simple.…”