HyperSizer Published Paper

"Failure Analysis of Adhesively Bonded Composite Joints via the Virtual Crack Closure Technique" (15 pages)


Phil Yarrington, Craig Collier, and Brett Bednarcyk


Failure analysis of bonded composite joints is essential to the design of modern aerospace vehicles where adhesive joints are widely used. Recently, methods for stress and failure analysis of composite bonded joints were implemented within the HyperSizer® stiffened panel design/analysis/optimization software package. The capability uses efficient, non-finite element based methods to calculate the adhesive stresses and detailed in-plane and out-of-plane interlaminar shear and peel stresses in the adherends for predicting damage initiation and failure. Previously, HyperSizer predicted failure using 19 different leading ply and interlaminar stress/strain-based fracture and delamination bonded joint failure theories. Now,the joint failure analysis capability has been extended to include damage tolerance residual strength by using the virtual crack closure technique (VCCT), which predicts the growth of an existing crack by comparing calculated strain energy release rates to critical values determined from tests. Implementation of VCCT, specific to the HyperSizer joint analysis method, is discussed and results are compared to finite element analysis and experimental results from the literature for composite and isotropic joint adherends.