NASA Technical Reports Server (NTRS) 20060026045: Damage Tolerance Analysis of Space Shuttle External Tank Lug Fillet Welds Using NASGRO

13.1 MB·English

by  NASA Technical Reports Server (NTRS)

Source of Acquisition
NASA Marshall Space Flight Center
Damage Tolerance Analysis of Space Shuttle External
Tank Lug Fillet Welds Using NASGRO
Abstract
The damage tolerance of the External Tank (ET) lug welds were reassessed because
of an increase in the loads due to the removal of the protuberance air load (PAT.,) ramp. The
analysis methods included detailed finite element analysis (FEA) of the ET welded lugs and
FEA of the lug weld test configuration. The FEA results were used as input to the crack
growth analysis code NASGRO to calculate the mission life capability of the ET lug welds
and to predict the number of cycles to failure in the lug weld testing. The presentation
presents the method of transferring the FEM results to the NASGRO model and gives
correlations between FEM and NASGRO stress intensity calculations.
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