Dynamic compression response of self-reinforced poly(ethylene terephthalate) composites and corrugated sandwich cores

Abstract

A novel manufacturing route for fully recyclable corrugated sandwich structures made from self-reinforced poly(ethylene terephthalate) SrPET composites is developed. The dynamic compression properties of the SrPET material and the out-of-plane compression properties of the sandwich core structure are investigated over a strain rate range 10 -4 s -1 to 10 3 s -1 . Although the SrPET material shows limited rate dependence, the corrugated core structures show significant rate dependence mainly attributed to micro-inertial stabilisation of the core struts and increased plastic tangent stiffness of the SrPET material. The corrugated SrPET cores have similar quasi-static performance as commercial polymeric foams but the SrPET cores have superior dynamic compression properties.

Impact response of ductile self-reinforced composite corrugated sandwich beams

“…A small change in yield strength from 74 MPa for the lowest tested strain rate to 87 MPa for the highest was however noted. As discussed in previous work [18], synthetic polymer fiber materials tend to show small strain rate dependence up to a specific transition point where the polymer chains "lock-up" and significant increase in stiffness and yield strength is observed. This transition point has previously been measured to 10 in compression loading of the SrPET material [18].…”

“…3b and a detailed discussion on the behaviour is found in [18,25]. A difference in tension and compression is seen in the post-yield behaviour at large strains where the compression specimens suffer from shear band formation and eventually also delamination [18].…”

“…Although a growing area of research, few studies have been performed on making composite sandwich structures out of SrPs [12,[16][17][18][19]. The quasi-static three-point bending properties of sandwich beams with a prismatic core has however recently been investigated by Schneider et al.…”

“…Material tests were performed both at low loading rates and at high loading rates (up to 1 m s -1 ). The compression properties have been investigated and discussed in previous work [18] and therefore only the tensile properties are investigated here. Structural impact tests were performed on clamped monolithic beams and on simply supported corrugated sandwich beams.…”

Bending energy absorption of self-reinforced poly(ethylene terephthalate) composite sandwich beams

“…Efforts have also been made to create fully recyclable sandwich materials with lattice and prismatic cores using SrPs [7,8]. These materials were tested in uniaxial compression and showed good quasi-static and dynamic mechanical properties and indicated the potential of producing high energy absorbing structures.…”