ENRICHMENT BASED MULTI-SCALE METHOD FOR MODELING TRANSIENT THERMOMECHANICAL EFFECTS ON COMPOSITE MATERIALS

摘要

Fielded and future military systems are increasingly incorporating composite materials into theirdesign. Many of these systems undergo rapid and severe changes in temperature, as well assubject the composites to environmental conditions which can cause micro damage leading tovariations of the mechanical properties on the global scale. For these applications, it is critical todevelop the ability to accurately model the response of composite materials, to enable engineersto accurately predict the response of the system. A widely popular approach to resolve this is toassume homogenized effective properties throughout the composite. However, this ideologybreaks down in critical areas when large thermal strains and micro-damage are prominent. Toalleviate these limitations, a multi-scale enriched partition of unity (POU) method is proposedwhich uses a multiscale enrichment approach, allowing macro-scale computations to beperformed with the micro-structural features explicitly considered. POU strategies have anadvantage in that the enriched local function space may be easily varied from one node to theother allowing variances in the microstructure, such as temperature gradients and localizeddamage to fibers.