Simulation of 3D non-planar fatigue crack growth in a turbine blade root
- Cornell Univ., Ithaca, NY (United States)
- Oak Ridge National Lab., TN (United States)
A case study of fatigue life predictions for the root of a turbine blade containing a initial flaw is presented. A fracture simulation system is utilized to perform simulations of low cycle (startup/shutdown) fatigue crack growth in the root. The turbine blade has a complex structural geometry, and the cracks have been observed to grow in a highly non-planar fashion. Simulation of these cracks requires the capability to model three-dimensional geometry and to allow for arbitrary non-planar crack growth. A geometric model of the portion of the root near the crack is created. Boundary conditions for this substructure are obtained from a finite element model of the entire blade (without a crack), loaded by centrifugal forces. One approach of transferring these boundary conditions to the geometric model is described. A small initial crack is added to the geometric model, and a linear elastic boundary element analysis is performed in order to compute the stress intensity factor variation (modes 1, 2, and 3) along the crack front. The crack growth rate curve for the blade material is used along with the mode-1 stress intensity factor variation to predict the number of cycles, and new crack shape, for a user-specified increment of growth. The model is then locally remeshed for the next boundary element analysis. Comparisons with experimental fatigue tests of this same configuration are presented. 39 refs.
- Research Organization:
- Oak Ridge National Lab., TN (United States)
- Sponsoring Organization:
- DOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 5659671
- Report Number(s):
- CONF-920631-7; ON: DE92006859
- Country of Publication:
- United States
- Language:
- English
Similar Records
Damage tolerance based life prediction in gas turbine engine blades under vibratory high cycle fatigue
Simplified methods of steam turbine blade root life analysis
Related Subjects
200104 -- Fossil-Fueled Power Plants-- Components
36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ALGORITHMS
COMPUTERIZED SIMULATION
CRACK PROPAGATION
EQUIPMENT
FRACTURE MECHANICS
MACHINERY
MATHEMATICAL LOGIC
MECHANICS
MESH GENERATION
SERVICE LIFE
SIMULATION
STEAM TURBINES
THREE-DIMENSIONAL CALCULATIONS
TURBINE BLADES
TURBINES
TURBOMACHINERY