Fatigue-crack-initiation numerical modelling of a Ni-base powder metallurgy alloy |
| |
| Authors: | MU Yuan-wei LU Shan ZHANG Hong |
| |
| Affiliation: | School of Power and Energy, Northwestern Polytechnical University, Xi'an 710072, China |
| |
| Abstract: | A simplified three-dimensional numerical model was presented to simulate the micro-crack nucleation and growth to some predefined dimension (approximately 0.38mm) on the throat surface of a Ni-base powder metallurgy (PM) specimen.The numerical simulation of micro-crack initiation was based on the Tanaka-Mura micro-crack initiation models, where individual grains of the mesoscopic model were simulated using the Voronoi tessellation.Four improvements were made in the model.(1) Considering crack initiation along with 12 principal slip systems on octahedral slip planes of face centered cubic (FCC) crystal in three-dimensional (3-D) models.(2) Considering the effect of secondary phase precipitate due to impinging slip and dislocation pileup.(3) The Tanaka-Mura theory of fatigue-crack-initiation from notches was applied to simulate the crack initiation from another crack tip.(4) The coalescence of random initiated micro-cracks was simulated once they intersected with each other and a macro-crack was finally formed.The calculated results were in good agreement with the experimental data which verified the rationality of the simulation model.The applicability of the proposed model for treating fatigue-crack-initiation life in engineering structures was preliminarily achieved. |
| |
| Keywords: | fatigue-crack-initiation numerical simulation slip system powder metallurgy Voronoi tessellation |
| 本文献已被 CNKI 万方数据 等数据库收录！ |
| 点击此处可从《航空动力学报》浏览原始摘要信息 |
|
点击此处可从《航空动力学报》下载全文 |
