Biaxial strength of paperboard predicted by hill-type theories

Abstract

Paperboard strength under biaxial normal plus shear stresses is predicted using Hill-type criteria (including Tsai-Hill, Norris, Fischer, and Ashkenazi). Results are compared throughout all four quadrants with experimental data obtained from on- and off-axis uniaxial coupons, cylinders, and cruciform specimens. The Norris and Fischer theories predict observation quite well except at higher values of shear stress where they become too conservative. The Tsai-Hill theory is conservative throughout. Simplicity of both analysis and implementation, plus need for only minimal experimental input data, are signficant advantages of Hill-type criteria. Moreover, their reliability for paper is comparable to that of other published results. Other strength theories will be addressed in subsequent papers.