Energy Release Rate Analysis At The Delaminationination Front Of Laminated Structures Based On Layerwise Theory

As an advanced structural material, composite has been widely used in the aerospace, transportation, machinery, chemicals, electrical power, military and etc. The failure of composite laminates may occur in many various forms, among which delamination accounts for a large proportion. Therefore the analyses of interlaminar stress and energy release rate at delamination front are of engineering significance.This work mainly includes the following two parts:(1) A series of formulas for analyzing the interlaminar stresses and displacements of laminated structures were derived from the Layerwise theory. On this basis, the in-plane stress and displacement of composite laminated beams were calculated through computer programming. The results of this paper were in good agreement with the results of relevant literature and Abaqus software and proved the validity and reliability of this algorithm.(2) Based on the first part of the work, the calculation model for the energy release rate at the front of laminated plate delamination(I and II) was established by introducing the virtual spring layer into the interface of the delamination and adopting the VCCT technology. Finally, the correctness was verified through specific examples.This paper creatively combined the Layerwise theory and the spring layer model together and employed the VCCT technology to calculate the energy release rate at two types of laminate delamination front. It presents a new model for the analysis of such problems.