Residual Stress Analysis within Structures using Incremental Hole Drilling

Residual stress analysis within hybrid structures is the focus of this study. The non linear stresses through the thickness are determined using a semi-destructive method known as Incremental Hole Drilling (IHD). Finite element modeling is used to build a mathematical code simulating GLARE laminates with initial residual stresses applied. The code includes the structure, orientation, mechanical and micro-thermal properties of the constituents into account. Matrices of elastic coefficients that represent the stress-strain relation within the laminate are found. In addition, strain responses are measured during incremental hole drilling of the GLARE laminates using tools specifically designed for hole drilling. Using the numerically determined matrices in conjugation with the experimental strain outputs lead to the computation of residual stresses. Verification and validation of the simulation models and the stress results are done through the use of theoretical methods such as the Classical Laminate Theory.Aerospace Engineerin