Spline Variational Theory for Composite Bolted Joints
Abstract
Three dimensional failure initiation and progression modeling and the experimental work required to verify the analysis methods were conducted. verify the analysis methods were conducted. Damage initiation and progression in the unidirectional and quasi-isotropic laminates was modeled based on the property degradation methodology. Reissner-Hellinger variational principle was applied to rigorously represent the degraded material properties in order to model the discrete damage at the hole edge. A recursive algorithm based on damage increment concept was developed to perform the damage evolution modeling. Both mechanical loading and residual stresses were taken into account. Conventional finite-element formulation based on linear displacement approximation was used. The analysis uncovered severe mesh type dependence of the damage evolution modeling based on conventional finite-element approximation. The results showed that only a specific class of finite-element meshes allows describing the stress relaxation in the fiber direction in unidirectional laminates with holes occurring due to matrix splitting under uniaxial tension. An experimental investigation has been conducted on the initiation and growth of damage in close proximity to the open hole for the +/-30/902s and 02/902s laminates under incremental tension loading. For both laminates the analytical predictions of strain calculated by spline variational theory and by elasticity showed good agreement with experimentally measured results. The development of damage observed by x-radiography was correlated with the stress-strain behavior.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 2000
- Accession Number
- ADA387588
Entities
People
- E. V. Iarve
- R. Y. Kim
Organizations
- University of Dayton