Finite-Width correction factors for sen testing of orthotropic materials in opening mode

Abstract

Abstract

Calculations of finite-width correction factors, Y, for mode I SEN tension testing of orthotropic materials have been made using a J integral implemented on results from finite element analyses. Y depends on the ratio of principal normal compliances S₁₁/S₂₂ and another dimensionless quantity involving the material compliances. Aspect ratio is fixed at 1 and normalized crack depth varies between 0.3 and 0.6. S₁₁/S₂₂ is fixed at four values; 20, 10, 1/10, and 1/20. Ranges of the other dimensionless material parameter relevant to existing materials are chosen. The use of linear interpolation for Y at intermediate values of S₁₁/S₂₂, and the relevance of the results to specimens with aspect ratios in excess of 1, are discussed. Y is presented at each value of S₁₁/S₂₂ in the form of a Chebyshev series in two variables. The results show that, if Y factors already established for isotropic materials are used to calculate stress intensity values for orthotropic specimens, errors in the stress intensity factor can be as high as 50 per cent.