Influence of a biaxially corrugated core geometry on flexural stiffness of wood -strand composite sandwich panels

The objective of this study is to gain an understanding of the influence of a biaxially corrugated core geometry on flexure stiffness of wood-strand composite sandwich panel for building construction applications where member deflections often govern the design. To this aim, a parametric study was conducted using a finite element (FE) model to understand the sensitivity of the bending stiffness of a wood strand composite core to all variations in its geometry. A unit cell (UC) in the core was defined to simplify the determination of all parameters capable of altering the core geometry. Although eight parameters were chosen for this parametric study, the interaction between these parameters in changing the geometry required simulation of 13 cases to fully understand the influence of these eight core parameters on the bending stiffness. The comparison between the bending stiffness normalized by the width of the test specimens not only indicated the effect of these parameters on the bending stiffness but also revealed the effectiveness of each parameter. Based on these results, the geometry of the core was redesigned to increase the flexural stiffness. The bending stiffness of the new and redesigned core was 43 % and 126 % stiffer than the initial core in the longitudinal and transverse directions, respectively. After manufacturing a new mold based on these result and fabrication of a wood strand core, the experimental results exceeded our expectation. The experimental results revealed that the bending stiffness of the new core is 59 % and 203 % higher than initial one in the longitudinal and transverse directions, respectively.