Publications

Publications

Statistical Fatigue and Residual Strength Analysis of New/Aging Aircraft Structure

This work describes a method for robust fatigue life prediction in aircraft by using a "splitting scheme" and the Finite Element Method to analyze complex, multi-crack scenarios. The approach efficiently calculates stress intensity factors, making large-scale statistical fatigue analysis practical for improving fleet management.

Fast and Reliable Solution of GDoF-Problems on NAVO/BABBAGE and AFRL/HAWK Systems

S.Fawaz and B.Anderson

This study details a specialized direct solver and a domain decomposition-based Finite Element methodology for solving Giga-Degree-of-Freedom structural analysis problems to enable reliable statistical fatigue and residual strength predictions for aging aircraft.

Impact Corner of the Barge During Its Glancing Blow Impact With a Lock Approach Wall

Robert M. Ebeling and Terry W. Warren

This report details a series of nonlinear Finite Element analyses conducted with LS-DYNA to determine the limiting impact force of a barge corner crushing during a glancing blow with a lock approach wall. A detailed FEA model of a barge bow, using over 177,000 shell elements and a nonlinear plastic material model, was subjected to simulated impacts to establish a "capping force" for existing design correlations.

Detailed 3D Modeling and Simulation of Bolted Connections

A.M. Citipitioglu and R.M. Haj-Ali

This paper presents a detailed three-dimensional Finite Element methodology using ABAQUS to simulate the nonlinear behavior of bolted steel connections by explicitly modeling contact, friction, and bolt pretension. The FEA models are validated against experimental data and then used to conduct parametric studies, demonstrating the approach's capability to accurately predict moment-rotation response and investigate component interactions.

EVALUATION OF THE StressWave COLD WORKING PROCESS ON HIGH-STRENGTH ALUMINUM ALLOYS FOR AEROSPACE

Eric T. Easterbrook and Michael A. Landy

This report evaluates a new fatigue enhancement method, Stress Wave Cold Working (SWCW), using extensive, post-yield Finite Element Analysis with LS-DYNA to understand and optimize the process. The FEA simulations, validated against experimental data, were used to model the residual compressive stresses and guide the design of tooling, ultimately confirming the new method's superior performance over conventional cold working.