NASA 1996 SBIR Phase I

PROJECT TITLE : Failure and Damage Tolerance of Composite Structures MSC P 0J30-631

TECHNICAL ABSTRACT (LIMIT 200 WORDS)

Constitutive laws for modeling nonlinear and strain softening behavior of composites due to multiple types of matrix mode damages as well as fiber breaks/kinks will be proposed, examined and validated. The models will be incorporated in a 3-D finite element code for stress analyses using iterative techniques. The constitutive laws will be refined by comparing predictions with available test data for specimens and components without and with stress raisers. The code will be used for predicting compressive failure of laminated fuselage shells as well as damage tolerance analysis of sandwich panels being considered for use in supersonic transports. Phase I will demonstrate the feasibility and usefulness of the analysis methods. Refinement and commercialization of the softwares/analysis methods are the goals of the following phases, which should also address the problem of fatigue and other environmental effects.

As composites are being considered for a wide range of civilian applications, from supersonic transports to infrastructures, reliable and widely applicable models and softwares are needed for design damage tolerance/durability analyses. The models and softwares will be useful for designing safer and lighter structures and will reduce the time and cost for design, analysis and testing. Government agencies may find its use in addressing certification issues in an efficient manner. Airframe manufacturers and other companies will obviously use the product if it can be used to design products by reducing cost and increasing safety.

Dr. Sailendra N. Chatterjee
Materials Sciences Corporation
500 Office Center Drive
Suite 250
Fort Washington, PA 19034

Materials Sciences Corporation
500 Office Center Drive
Suite 250
Fort Washington, PA 19034