In materials science, fracture toughness KIc is a property which describes the ability of a material to resist fracture, and is one of the most important properties of any material for many design applications. The linear-elastic fracture toughness of a material is determined from the stress intensity factor KI at which a thin crack in the material begins to grow. It is denoted KIc and has the units of N/m^3/2.
Then the stress intensity factor KI is not a property and is equal to the fracture toughness KIc at the material begins to grow.
In materials science, fracture toughness KIc is a property which describes the ability of a material to resist fracture, and is one of the most important properties of any material for many design applications. The linear-elastic fracture toughness of a material is determined from the stress intensity factor KI at which a thin crack in the material begins to grow. It is denoted KIc and has the units of N/m^3/2.
Then the stress intensity factor KI is not a property and is equal to the fracture toughness KIc at the material begins to grow.