An experimentally verified finite element study of the stress-strain response of crack geometries experiencing large-scale yielding
- NASA Ames Research Center, Moffett Field, CA (United States). Materials and Failure Analysis Group
- Stanford Univ., CA (United States). Mechanical Engineering, Design Div.
Large-strain, 3-D finite element analyses with incremental plasticity were performed for a variety of crack geometries to study local crack-tip stress-strain fields and associated global fracture parameters under conditions of large-scale yielding. The geometries analyzed include thin, single-edge crack tension, single-edge crack bending, and center-crack tension fracture specimens with varying crack depth (a/W) ratios. Two materials were investigated: a high-hardening, low-strength steel and a moderate-hardening, high-strength steel. Mesh refinement studies were performed to ensure convergence of the finite element predictions. The studies examine the effects of in-plane crack-tip element size, initial crack-tip radius size, and number of through-thickness layers on predicted distributions of crack-tip stress and plastic strain and predicted values of the J-integral and CTOD. In addition, the finite element predictions of specimen behavior were verified experimentally by direct measurements, namely load displacement, load longitudinal strain, and load CTOS, made during and following testing of the fracture specimens. Representative results of the finite element analyses are presented and compared to previously published data where pertinent. Results from the mesh refinement studies and the verification testing are shown. Predicted trends among the specimens and materials in local distributions of crack-tip plastic strain, triaxiality, and opening stress as well as in global parameters, J-integral and m-factor, are discussed.
- OSTI ID:
- 544223
- Report Number(s):
- CONF-950618--
- Country of Publication:
- United States
- Language:
- English
Similar Records
The relationship between constraint and ductile fracture initiation as defined by micromechanical analyses
A software framework for two-dimensional mixed mode I/II elastic-plastic fracture