José Gonilha

GFRP sandwich panels with PU foam and PP honeycomb cores for civil engineering structural applications

Purpose – The purpose of this paper is to present experimental investigations on the structural behaviour of composite sandwich panels for civil engineering applications. The performance of two different core materials – rigid plastic polyurethane (PU) foam and polypropylene (PP) honeycomb – combined with glass fibre reinforced polymer (GFRP) skins, and the effect of using GFRP ribs along the longitudinal edges of the panels were investigated.Design/methodology/approach – The experimental campaign first included flatwise tensile tests on the GFRP skins; edgewise and flatwise compressive tests; flatwise tensile tests on small‐scale sandwich specimens; and shear tests on the core materials. Subsequently, flexural static and dynamic tests were carried out in full‐scale sandwich panels (2.50×0.50×0.10 m3) in order to evaluate their service and failure behaviour. Linear elastic analytical and numerical models of the tested sandwich panels were developed in order to confirm the effects of varying the core mater...

Glass fibre reinforced polymer pultruded flexural members: assessment of existing design methods

Glass fibre reinforced polymer (GFRP) pultruded profiles are being increasingly used in bridge and building construction as an alternative to traditional materials because of their several favourable properties that include high strength, low self-weight, short installation times, low maintenance requirements and improved durability. In spite of these advantageous characteristics, there are some factors delaying the widespread use of GFRP pultruded profiles in civil infrastructure, one of which is the lack of widely accepted design codes. This paper presents the results of analytical, experimental and numerical investigations on the structural behaviour of GFRP pultruded profiles, the objective of which was to evaluate the relative accuracy of existing design methods. A survey of analytical formulae available for the design of GFRP pultruded flexural members at both service and ultimate limit states is first presented. Subsequently, results of a test programme carried out at Instituto Superior Técnico (IST) are briefly discussed—the experiments included material characterization tests and full-scale flexural tests on I-section simply supported beams and cantilevers. These tests allowed for the evaluation of the service behaviour of GFRP flexural members and some of their most relevant failure mechanisms and respective ultimate loads. Results from experimental tests are compared with those obtained from analytical formulae and numerical models in order to evaluate the relative accuracy of existing design methods.