Flexural behaviour of hybrid sandwich panel with natural fiber composites as the intermediate layer

Flexural behaviour of hybrid sandwich panel with natural fiber composites as the intermediate layer

Polymeric composites reinforced with natural fibers have raised more attention as the alternative building materials. In this work, natural fiber composites prepared from jute and hemp fiber were proposed for the intermediate layer of a hybrid sandwich panel. This paper presented the flexural behavior of the newly developed hybrid sandwich panel which included the comparison of the ultimate load, load-deflection behavior, load-strain behavior and failure modes. The study was designed as a single factor experiment where the performance of hybrid sandwich panels containing jute fiber composite (JFC) and hemp fiber composite (HFC) as the intermediate layer was compared to the control (CTR) which was a conventional sandwich panel without an intermediate layer. A static flexural test under a four-point bending load scheme was performed in accordance with the ASTM C 393-00 standard. Aluminium sheet was used as the skins, while expanded polystyrene (EPS) was employed for the core. The testing was performed using a 100 kN servohydraulic machine with a loading rate of 5 mm/min. The applied load, displacement and strains were obtained using data logger. The results demonstrated that the hybrid sandwich panel exhibited a more superior performance than the conventional sandwich panels. The intermediate layer contributed significantly to enhancing the load carrying capacity of the hybrid sandwich panel. The load carrying capacity of hybrid panel with the JFC intermediate layer was 29.60% higher than the conventional sandwich panel, and correspondingly 93.46% higher for the sandwich panel with the HFC intermediate layer. The hybrid sandwich panels also developed a much larger area under the load-deflection curve, indicating greater toughness. The introduction of intermediate layer helped the hybrid sandwich panels to sustain a larger strain prior to reach their ultimate loads, resulting in a higher deformation capability. Indentation and core shear were observed as the failure mode of the conventional sandwich panel. Meanwhile, core shear and delamination were identified as the failure mode of the hybrid sandwich panel.