If you are looking for free foundational material on classical plasticity theory, consider these open-access academic sources:
: The official publisher offers the eBook for purchase . You may have free access if you are affiliated with a university or library that has a SpringerLink subscription. Elements of Classical Plasticity Theory free eb...
: Authors often upload similar content, such as A Short Introduction to the Theory of Plasticity or Classical Elasticity and Plasticity. If you are looking for free foundational material