Composite Materials for Structural Design.
Abstract
Research activities related to advanced fiber reinforced plastics are reported in detail for the final year of the initial contract on the continuing composites program at Texas A&M. Work was initiated or continued in the areas of fracture, delamination, fatigue, and residual stresses in elastic and viscoelastic composites. Delamination fracture toughness is investigated using macroscopic measurements of fracture toughness to determine critical energy release rate for crack propagation and is interpreted in terms of microscopic mechanisms of fracture determined from careful examination of the fracture surface using a scanning electron microscope. Additional experimental work in compression-induced delamination and delamination under complex load histories is presented. Analytical methods are developed for prediction of the mechanical state and energy release rate for delamination and used in the investigation of tensile coupons with various amounts of delamination and matrix degradation due to microcracking. A viscoelastic crack growth theory for nonlinear media was developed earlier in the program and this work is being extended to develop a damage theory of laminates. An investigation of the effects of moisture and temperature on residual stresses in composite laminates is continuing. Solution forms which relate curvatures in unsymmetric cross-ply laminates to temperature excursions and moisture content, including viscoelastic effects, were formulated and programmed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1982
- Accession Number
- ADA122262
Entities
People
- J. S. Ham
- R. A. Schapery
- W. E. Haisler
- W. L. Bradley
- Y. Weitsman
Organizations
- Texas A&M University