Mechanical characteristics of SCh15-32 cast iron in the plane stressed state

Abstract

1. The ability of cast iron to resist changes in volume under conditions of first loading and steady elasticity with loading conditions −1≤α≤0.5 decreases sharply with increasing stress levels. Under conditions where the component of the compressive stress σ3 has a higher absolute value than the component of the tensile stress σ1 the resistance of cast iron to changes in volume increases sharply. With an increase of the stress level the value of\(K_{I\left| {\alpha = - 1.65} \right|} = f = (\sigma _1 )\) (during first loading) decreases somewhat. With increasing stress levels during steady elasticity the ability of cast iron to resist changes in volume\(K_{y\left| {\alpha = - 1.65} \right|} = f = (\sigma _1 )\) increases. 2. With increasing stress levels the ability of cast iron to resist shear strain changes less than the ability to resist changes in volume. Beginning at some stress level, the resistance to shear strain becomes more stable and during steady elasticity the variation of Gy with σ1 approaches the asymptotic, approximating a straight line parallel to the x axis σ1. 3. The obtained characteristics of the elastoplastic deformation, elasticity, resistance to changes in volume and shear strain and the relations governing their changes in relation to the stress level and loading conditions make it possible to determine the range of applications for cast iron in machine construction. By means of these characteristics it is also possible to explain several phenomena that occur in cast iron structures during operation.