On the theoretical modeling of fatigue crack growth
| Autor: | Robert O. Ritchie, Brian P. Somerday, Mohsen Dadfarnia, Zahra S. Hosseini, Petros Athanasios Sofronis |
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| Rok vydání: | 2018 |
| Předmět: |
Work (thermodynamics)
Structural material Materials science Mechanical Engineering Fracture mechanics 02 engineering and technology Mechanics Paris' law 021001 nanoscience & nanotechnology Condensed Matter Physics Measure (mathematics) Plastic dissipation Finite element method 020303 mechanical engineering & transports 0203 mechanical engineering Mechanics of Materials Cyclic loading 0210 nano-technology |
| Zdroj: | Journal of the Mechanics and Physics of Solids. 121:341-362 |
| ISSN: | 0022-5096 |
| Popis: | Although fatigue is by far the most common mode of failure of structural materials, mechanistic understanding is still lacking. For example, the fundamental Paris law which relates the crack growth rate to stress-intensity factor range is still phenomenological and no reliable mechanistic model has been established for a given material or class of materials despite numerous investigations over a half a century. This work is an attempt to theoretically model fatigue crack propagation induced by alternating crack-tip plastic blunting and re-sharpening in the mid-range of growth rates on the basis of inputs from experiments that measure macroscopic material behavior, e.g., response to uniaxial cycling loading. In particular, we attempt to predict Paris law behavior by accounting for the material constitutive behavior in response to cyclic loading by modeling crack advance solely in terms of the underlying plastic dissipation. We obtain the steady-state condition for crack growth based on plastic dissipation, numerically using finite element analysis, which involves a methodology to address plastic closure upon unloading. For a given stress-intensity range, we calculate the crack propagation rate from the steady-state condition through each cycle of loading and unloading of a cracked compact-tension specimen, without resorting to any specific criterion for crack advance. |
| Databáze: | OpenAIRE |
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