Analytical and Experimental Characterization of Damage Processes in Composite Laminates.
Abstract
A summary of results is presented on the subject of damage development in metal and polymer matrix composite laminates. The following technical developments are described: (i) Evaluation of crack densities, stiffness changes, and fiber stresses caused by cyclic loading in three 6061-0 AlB laminates, with O8 (0/90)2s, and (o/+ or - 45/90/0 + or - 45/1/290s) layers. This problem is solved in an incremental way, with regard for interaction between plastic deformation and matrix crack growth in individual plies. Saturation damage states are predicted at different levels of steady cyclic loading. Good comparison is obtained with available experimental data, (ii) Analysis of first ply failure in polymer matrix composites. The influence of ply thickness on strength is predicted in terms of flaw nucleation mechanisms, and (iii) Analysis of distributed damage caused in a composite ply by either transverse cracks or fiber breaks. Several methods, such as self-consistent estimates, shear lag approximations, crack array models, and finite element analysis of cracks in an embedded ply were employed. It was found that these methods give very similar predictions of stiffness reductions of plies and laminates, and that these predictions are in good agreement with available experimental data.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1986
- Accession Number
- ADA174991
Entities
People
- George J. Dvorak
- Norman Laws
Organizations
- Rensselaer Polytechnic Institute