STRESS-FOCUSING EFFECT IN A SOLID SPHERE CAUSED BY INSTANTANEOUS UNIFORM HEATING

When a solid sphere is subjected suddenly to a uniform temperature rise over its cross section, a stress wave occurs at the surface the moment thermal impact is applied. The stress wave at the surface proceeds radially inward to the center of the sphere. The wave may accumulate at the center and give rise to very large stress magnitudes, even though the initial thermal stress is relatively small. This phenomenon is called the stress-focusing effect. This paper analyzes the effects of these waves precisely using the ray theory. The numerical results give clear indications of a stress-focusing effect in spheres.