Bending creep rupture analysis using a non-linear energy criterion approach

Abstract

Creep rupture analysis by simple bending induces a larger and therefore more accurately measured creep deflection. It also considers both tensile and compression behaviour simultaneously. However, the common assumption of a linear stress distribution across the cross-section of the beam leads to a nominal value for the calculated rupture stress. In this paper, the true bending rupture stresses for a wood polymer composite beam was determined using a Norton-Bailey or power creep deformation analysis. These values were then used to model the creep rupture behaviour of the material, using an energy criterion approach. The results indicated that a non-linear consideration consistently resulted in higher values for the elastic and anelastic modulus, as well as the upper and lower creep rupture stress limits. © 1990.