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Characterization of residual stress effects on fatigue crack growth of a friction stir welded aluminum alloy
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Seshadri, Banavara R. Brazill, Richard L. Smith, Stephen W. James, Mark A. Blair, Amy Donald, J. Keith Newman, John A. Schultz, Robert W. |
| Copyright Year | 2015 |
| Description | An on-line compliance-based method to account for residual stress effects in stress-intensity factor and fatigue crack growth property determinations has been evaluated. Residual stress intensity factor results determined from specimens containing friction stir weld induced residual stresses are presented, and the on-line method results were found to be in excellent agreement with residual stress-intensity factor data obtained using the cut compliance method. Variable stress-intensity factor tests were designed to demonstrate that a simple superposition model, summing the applied stress-intensity factor with the residual stress-intensity factor, can be used to determine the total crack-tip stress-intensity factor. Finite element, VCCT (virtual crack closure technique), and J-integral analysis methods have been used to characterize weld-induced residual stress using thermal expansion/contraction in the form of an equivalent delta T (change in local temperature during welding) to simulate the welding process. This equivalent delta T was established and applied to analyze different specimen configurations to predict residual stress distributions and associated residual stress-intensity factor values. The predictions were found to agree well with experimental results obtained using the crack- and cut-compliance methods. |
| File Size | 828543 |
| Page Count | 25 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20150002817 |
| Archival Resource Key | ark:/13960/t8qc51f1x |
| Language | English |
| Publisher Date | 2015-02-01 |
| Access Restriction | Open |
| Subject Keyword | Metals And Metallic Materials In Situ Measurement J Integral Fatigue Life Crack Tips Temperature Gradients Tensile Tests Aluminum Alloys Crack Closure Crack Propagation Finite Element Method Stress Intensity Factors Friction Stir Welding Spacecraft Structures Prediction Analysis Techniques Residual Stress Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
