Fully plastic ductile tearing of HY130 steel—an analysis by J, COD, energy rate and crack opening angle
| Autor: | M Dagbasi, C E Turner |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
Toughness
Materials science business.industry Applied Mathematics Mechanical Engineering Fracture mechanics Structural engineering Work hardening Dissipation Shear (sheet metal) Fracture toughness Mechanics of Materials Modeling and Simulation Tearing Composite material business Displacement (fluid) |
| Zdroj: | The Journal of Strain Analysis for Engineering Design. 30:257-269 |
| ISSN: | 2041-3130 0309-3247 |
| DOI: | 10.1243/03093247v304257 |
| Popis: | The dependence of J-R curves on size of test piece is examined for fully plastic deep notch bend (DNB) tests on HY130 steel, taken to large amounts of ductile crack growth (60 per cent of the ligament) for a range of initial widths at 20 mm thick and one geometrically similar size, 50 mm thick. The object is to understand the cause of the widely different patterns of behaviour that have been reported in the literature, even within the DNB type of configuration. In the present tests, the proportion of shear lip is the same for the geometrically similar pair but the J-R curve for the 50 mm thick piece is much lower than for the similar piece, 20 mm thick. The rate of change of displacement, dq/da, is analysed using the factor. r∗, that defines the instantaneous centre of rotation at each step of growth, to give a measure of crack tip opening angle (CTOA), xg. After an initial transient regime of small growth, xg and r∗ remain constant. The normalized load. L, rises due to work hardening during crack growth by amounts that depend on size while xg and r∗ vary mildly with initial width to give an appreciable variation of the combined term Lxg/r∗, which is the factor that controls the behaviour of the JR curves. It is speculated that CTOA and its variation with configuration (as seen in the literature) may, for large growth, assume the role of the two parameters suggested in recent literature as controlling the variation of toughness with constraint. |
| Databáze: | OpenAIRE |
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