Experimental investigation of nonlinear stress-strain behaviour of various elastomeric materials under cyclic loading

This study investigates the nonlinear mechanical responses of elastomeric materials under complex loading paths. The experimental programme involved a series of uniaxial tensile and compressive tests under various loading protocols, systematically comparing the mechanical responses of different materials. The results show that amorphous polymers, including Thermoplastic Polyurethane, Neoprene rubber, and Neoprene/NBR rubber, exhibit more linear (elastic) load–unload behaviour, with improved shape recovery, resistance to stress relaxation, and reduced residual strain, although their energy dissipation capacity remains limited. In contrast, semi-crystalline polymers, including Polypropylene, Ultra-High-Molecular-Weight Polyethylene, and High-Density Polyethylene, demonstrate pronounced strain-dependent behaviour. As the strain increases, stress softening and cyclic relaxation effects are reduced. These materials exhibit significant energy dissipation but considerable residual strain. A key outcome of this research is that Thermoplastic Polyurethane presents the most favourable combination of high stress retention, low residual strain, and creep resistance, making it a strong candidate for use in the segmental construction of prefabricated bridges as a seismic damage-avoidance element. Ultra-High-Molecular-Weight Polyethylene, when combined with post-tension systems, also shows potential due to its strain hardening and enhanced energy dissipation, thereby improving seismic resilience under major events. These findings provide valuable insights into the deformation mechanisms of elastomeric materials and offer practical guidance for their effective implementation in energy-dissipating structural systems.