科研之友
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摘要
The extended finite element method (X-FEM) is a promising and efficient tool to calculate stress intensities in fatigue crack growth analysis. An X-FEM approach is presented to simulate the fatigue growth of 3-D multiple cracks. Level set functions are used to characterize the cracks. A novel explicit/implicit hybrid description of cracks is introduced to follow up the crack growth and update level set functions, in which the reconstruction of crack surface is suggested to keep the crack smooth in crack growth simulation. The crack linking-up is also modeled with the hybrid description scheme. A stable partition algorithm is introduced to perform robust integration in the elements with discontinuities. The interaction integral method is adopted to evaluate the mix-mode stress intensity factors and the crack growth are characterized by mix-mode Paris law. As a practical application, the fatigue crack growth simulations are conducted on 30CrMnSiA steel alloy specimens with coplanar and non-coplanar double surface cracks. The simulated double crack growth paths and their coalescence behavior agree well with the experimental results. The proposed hybrid crack description method is efficient and with low computational cost.
- 出版日期2017-9
- 单位西北工业大学
