A method for modeling material behavior includes using empirical three dimensional non-uniform stress and strain data to train a self-organizing computational model such as a neural network. A laboratory device for measuring non-uniform stress and strain data from material includes an enclosure with an inclusion in it. As the enclosure is compressed, the inclusion induces a non-uniform state of stress and strain. A field testing device includes a body having a moveable section. When the body is inserted in a material and the moveable section moved, a non-uniform state of stress and strain can be characterized.