MMF&EFM: an innovative science-based methodology for modeling and simulating Composite Materials for Durability

Conventional damage tolerance assessments of metallic structures based on crack growth generally do not apply to composites. The current practice of residual strength assessment based on small BVID (barely visible impact damage) and large CDT (critical damage threshold) damage is known to increase service repair costs of thin composite honeycomb panels. There is, therefore, a need to develop better damage tolerance assessment analysis methodologies. KaZaK Composites, Incorporated proposes to utilize their expertise and experience in damage tolerance assessment, mechanical property modeling and life prediction of polymer matrix composites to develop an advanced damage evaluation tool for the USAF. In the proposed work, analysis and tests will be performed to determine the structural strength and integrity of a traditional composite material with controlled defects. A new constituents and micromechanics-based (MMF) and element-failure method (EFM) approach to failure initiation and progression for composites will be employed in the analysis methods for both cases. This advanced numerical tool will begin to be used in association with commercial finite element software to provide the Army with an obvious transition path to assessing composites durability for current applications.