Lessons Learned to Improve HCF Demonstration Tests
Abstract
New turbine engine component designs are subjected to structural characterization tests to verify that vibratory stresses are below high-cycle fatigue (HCF) limits at various engine operational conditions. These tests are sometimes conducted in an altitude test chamber with a heavily instrumented engine where a limited number of altitude/Mach number test conditions are simulated to characterize component vibratory stresses. If the vibratory stress measurements from these characterization tests are below predefined limits (usually 60 percent Goodman limit), the part passes and the component development process will often continue to a durability demonstration phase. The engines that are used for durability demonstration tests, such as Accelerated Mission Testing (AMT), usually don't have instrumentation to measure component vibratory stresses. The durability demonstration tests are often designed to accumulate low-cycle fatigue (LCF), creep, and wear mode damage that is caused when the engine cycles between low- and high-power settings. Some tests might be performed specifically to demonstrate that the engine components will not experience HCF damage during field us, (for instance, an HCF stair-step test), but comparison between test and field vibratory load spectra is often limited because of the lack of instrumentation of the test engines.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 2005
- Accession Number
- ADA469578
Entities
People
- Steve Arnold