Constitutive behavior and failure criteria for composites under static and dynamic loading

The technology of composite materials has experienced dramatic developments in the last four decades with continuously expanding applications. Further development depends to a great extent on the introduction of new material systems and a rapid evaluation of the resulting composites. To facilitate and accelerate this process, it is important to develop/establish comprehensive and effective methods and procedures of constitutive characterization and modeling and failure prediction of structural laminates based on the properties of the constituent materials and especially the basic building block of the composite, the single ply or lamina. The plethora of available composite failure theories coupled with a dearth of reliable experimental data provides no definitive answer as to the best general approach to failure prediction. A new failure theory recently developed at Northwestern University has been proven very successful in predicting failure of a composite lamina under multi-axial states of stress and varying strain rates in cases where the biggest discrepancies were observed in predictions by other theories.