Polymer Matrix Composites: The case of pentamodes

Pentamodes are known for their almost zero shear modulus. Polymer Matrix Composites are renowned for multiple advantages, such as their ability to withstand harsh conditions and prolonged usage. In the current study, a combination of these two technologies, i.e. Pentamode-based Polymer Matrix Composites (PPMCs) are proposed for application in seismic isolation. Bearings composed of pentamode layers embedded into polymer matrices are proposed. It is demonstrated that PPMCs feature a shear response improved up to 33 % compared to conventional pentamode specimens. By adding stiffening plates to PPMCs their compressive response can be improved up to 24 %. PPMCs with layers rotated every 45° are suggested to overcome the pentamodes’ anisotropy and their shear stiffness is proved to be increased by up to 26 %. The bearings’ failure mechanisms confirm the aforementioned findings. Real-life seismic excitations illustrate the applicability of PPMCs in seismic isolation and highlight the shear response improvement of up to 39 % offered by PPMCs compared to conventional pentamode devices.