Analysis of twist stiffness of single and double-wall corrugated boards

The twist stiffness of single and double-wall corrugated board is analyzed using first order shear deformation (FOSD) theory. Results are compared to finite element analysis (FEA) and dynamic test data for a large range of torsion loaded rectangular board specimens. The FOSD approach and FEA employ a homogenized core. In addition, a structural finite element model was developed where the web core is represented by shell elements. According to FOSD analysis, the twist stiffness is linearly dependent on the transverse shear moduli of the web core along both principal directions of the core. Good agreement between the torsional stiffness predictions by analytical and numerical approaches and test results is found for the range of single and double-wall boards examined. The FOSD solution is significantly less computationally demanding than FEA, and appears viable for prediction of the twist stiffness of corrugated board.