Flexural behavior of fiber reinforced composites sandwich panels with a reused wooden core

The increasing use of wood products has inevitably resulted in a fast accumulation of waste wood, which is commonly landfilled or recycled for energy or products with low added value. In the present study, a concept has been adopted to reuse the waste wood formwork as the core of FRP sandwich panels. The waste wood formwork has been firstly sliced into wood strips of a specific width, which are then flipped by 90o and bonded together to form a plate as the sandwich core. Such a recycling routine appears as a promising method due to (1) minimum pre-treatment for processing the waste wood; and (2) less likelihood of the hazardous chemicals leakage because of the covered GFRP skins. The flexural behavior of such sandwich panels has been evaluated through a series of three-point bending tests with the thicknesses of GFRP layer and the core plate as the main parameters. The test results indicate that the GFRP-waste wood sandwich panels failed by either rupture of the tensile GFRP sheet or crushing of the compression side. The bending stiffness and flexural strength improves with the increase in the thicknesses of the core plate and GFRP layer, and the panels with three-layer GFRP sheets have the bending stiffness and flexural strength up to 11.0 and 4.4 times higher than that of the core plate. The analytical and numerical predictions on the flexural properties of the sandwich plate show in good agreement with that from the tests, validating the adopted the models.

Automated summary

This study proposes a novel method of reusing waste wood formwork as the core of FRP sandwich panels. The bending behavior of these panels is evaluated through experiments and numerical simulations, demonstrating that increasing the thickness of the core plate and GFRP layer improves the bending stiffness and strength of the panels.