A Plastic Hinge Model to Evaluate the Structural Performance of Casts

Abstract

Published manuscripts have described the material properties of casting materials by using simple material testing techniques such as three-point bending and by using flexure equations which calculate material strength and stiffness. These equations assume the cast is exposed to small deformations, bends with a uniform curvature and acts as a beam. These conditions are not met in some applications since the cast/limb structure may be designed for compliance and large deformation. The flexure equation should be replaced with the plastic hinge concept which provides a better description of the mechanical behavior of cast and a better means to predict the failure behavior of the cast/limb structure.