Stochastic-Strength-Based Damage Simulation Tool for Ceramic Matrix and Polymer Matrix Composite Structures

Download or read book Stochastic-Strength-Based Damage Simulation Tool for Ceramic Matrix and Polymer Matrix Composite Structures written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-05-22 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stochastic-based, discrete-event progressive damage simulations of ceramic-matrix composite and polymer matrix composite material structures have been enabled through the development of a unique multiscale modeling tool. This effort involves coupling three independently developed software programs: (1) the Micromechanics Analysis Code with Generalized Method of Cells (MAC/GMC), (2) the Ceramics Analysis and Reliability Evaluation of Structures Life Prediction Program (CARES/ Life), and (3) the Abaqus finite element analysis (FEA) program. MAC/GMC contributes multiscale modeling capabilities and micromechanics relations to determine stresses and deformations at the microscale of the composite material repeating unit cell (RUC). CARES/Life contributes statistical multiaxial failure criteria that can be applied to the individual brittle-material constituents of the RUC. Abaqus is used at the global scale to model the overall composite structure. An Abaqus user-defined material (UMAT) interface, referred to here as "FEAMAC/CARES," was developed that enables MAC/GMC and CARES/Life to operate seamlessly with the Abaqus FEA code. For each FEAMAC/CARES simulation trial, the stochastic nature of brittle material strength results in random, discrete damage events, which incrementally progress and lead to ultimate structural failure. This report describes the FEAMAC/CARES methodology and discusses examples that illustrate the performance of the tool. A comprehensive example problem, simulating the progressive damage of laminated ceramic matrix composites under various off-axis loading conditions and including a double notched tensile specimen geometry, is described in a separate report. Nemeth, Noel N. and Bednarcyk, Brett A. and Pineda, Evan J. and Walton, Owen J. and Arnold, Steven M. Glenn Research Center STOCHASTIC PROCESSES; MICROCRACKS; SIMULATION; CERAMIC MATRIX COMPOSITES; POLYMER MATRIX COMPOSITES; FINITE ELEMENT METHOD; MICROMECHANICS; SOFTWARE DEVELOPMENT TOOLS; SOFTWARE ENGINEERING; DAMAGE; BRITTLE MATERIALS; COMPOSITE STRUCTURES; CRACK INITIATION; CRACK PROPAGATION; FRACTURE MECHANICS; PROBABILITY THEORY; STRESS-STRAIN RELATIONSHIPS; STRUCTURAL ANALYSIS