Effect of Characteristic Lengths of Fracture on Thermal Crack Patterns

Abstract

Approximately uniformly spaced cracking occurs in many different materials and processes during thermal or drying shrinkage. Such cracks may occur when a slab of material restrained at the bottom is subjected to a sudden reduction in temperature at the top. Previous research indicates that the crack patterns obtained depend on the Griffith crack length for a shrinking solid. This paper shows that for materials exhibiting elastic-plastic fracture behavior, the fracture energy, Young’s modulus, and tensile strength in combination form a second characteristic length of fracture of the material that has a significant impact on the cracks formed.