Accurate Strength & Life Prediction

Progressive Damage Subcomponent Validation: Completed test/analysis correlation for four-stringer test articles with initial damage, Teflon inserts or impact damage, subjected to static loading and single-stringer specimens with Teflon inserts subjected to fatigue loading. The analyses predicted well the observed damage modes and sequence of damage events and predicted max loads within 15% of the average experimental failure load for the four-stringer panel with Teflon inserts.

    High Energy Dynamic Impact Complex Subcomponent Validation: Post-test simulations of the sub-scale curved configured test article were conducted with LS-DYNA MAT162, MAT261 and Peridynamics and compared with test results.  For backside deflection in the mid-bay area, Peridynamics showed the best correlation with test data at -17.5% error of the peak value, meeting the minimum success criterion.  MAT162 and MAT261 over-predicted the deflection at 103.5% and 38.3% respectively.  For the threshold penetration velocity the MAT261 model provided the most accurate prediction, with an error of less than 4% compared to the test result, meeting the stretch success criterion.

     Rapid Design Tools - Optimizer Demo on Component:  BVID/CAI and Ply-Drop (UTRC), 2-Bay Crack (Spirit/Boeing), Post-buckling and Bonded Joint (Collier), were validated through exercising the tools and comparing results to test data. Team members (Collier, Aurora, Spirit AeroSystems, Boeing, Northrop Grumman, UTRC, NASA) used the HyperSizer® stress framework with rapid tools integrated to analyze/size global finite element models of company-specific structures. Some members reported qualitative and quantitative benefits using the stress framework regarding design cycle times.