Analysis of Innovative Composite Aircraft Structures

Thermal Barrier Coatings (TBC) have been used for almost three decades for heat insulation in high-temperature components to increase efficiency. Reliable diagnostic techniques that are practical to implement are needed to identify the location and severity of degradation in TBCs to protect against premature TBC failure.

The relationships between a resistance curve (R-curve), the corresponding fracture process zone length, the shape of the traction/displacement softening law, and the propagation of fracture are examined in the context of the through-the-thickness fracture of composite laminates. A procedure that accounts for R-curve toughening mechanisms by superposing bilinear cohesive elements is proposed.

ILC Dover, under contract by NASA Langley Research Center, and in cooperation with NASA Johnson Space Center is designing and manufacturing an expandable lunar habitat.

Structures in general are subject to uncertainty due to manufacturing, assembly, environment of work, loads, etc … This scatter more specifically is associated for example to tolerances of thickness, position, waviness, etc, material mechanical properties distribution, layup alignment axes.

An Abaqus/Standard FEA based study was carried out to develop a structural format for a wing sail used on a sailing boat, V-39 Albatross. As well as providing a novel structural solu-tion to meet a challenging set of requirements, the study has given the necessary mass properties and stiffness data required to further progress the preliminary design phase of the overall boat.

A unified framework is presented that enables coupled multiscale analysis of composite structures and associated graphical pre and post processing within the Abaqus/CAE environment. The recently developed, free, Finite Element Analysis - Micromechanics Analysis Code (FEAMAC) software couples NASA's Micromechanics Analysis Code with Generalized Method of Cells (MAC/GMC) with Abaqus/Standard and /Explicit to perform micromechanics based FEA such that the nonlinear composite material response at each integration point is modeled at each increment by MAC/GMC.

The ability to accurately model welding processes in order to predict residual stresses and distortions is becoming increasingly important in the engineering industry. Abaqus can be used to model the welding process but this has been found to be considerably time consuming and requires a large number of assumptions to be made. Virtual Fabrication Technology is an analysis software suite that is designed to allow Abaqus to accurately model complex welding procedures.

Guidelines and Parameter Selection for the Simulation of Progressive Delamination

A software tool for automated crack onset and growth simulations based on the eXtended Finite Element Method (X-FEM) has been developed. For the first time, this tool is able to simulate arbitrary crack growth and composite delamination without remeshing. The automated tool is integrated with Abaqus/Standard and Abaqus/CAE via the customization interfaces.