This short blog post is based on the one of the question I have received from a researcher/student who follows my channel and webpage.
When simulating the behaviour of materials under high strain rates or extreme loading conditions, it’s important to accurately predict when and how they will fail. Two commonly used models for this purpose are the Hashin damage model and the Johnson-Cook model.
The Hashin damage model was developed in the 1970s by Zvi Hashin & A. Rotem. It is a phenomenological model that describes the relationship between the damage caused by an applied stress in the fibre-reinforces composite materials. These criteria consider four different damage initiation mechanisms: fibre tension, fibre compression, matrix tension, and matrix compression.
The Johnson-Cook model was developed in the 1980s, is a constitutive model that describes the relationship between the stress state of a material and its deformation and failure. It is commonly used to simulate the behaviour of metallic materials under high strain rates, such as those encountered in high-velocity impact or ballistic penetration. The model is based on the idea that the flow stress of a material is a function of its strain rate, temperature, and prior deformation history. The model includes a damage parameter, which increases as the material is loaded and eventually leads to failure.
In conclusion, the Hashin damage model and the Johnson-Cook model are two commonly used models for predicting material damage and failure under different loading conditions. Each model has its own strengths and weaknesses, and the choice of which model to use will depend on the specific material and loading conditions being simulated.