论文全文 - 设计智能制造2023学术年会 高强化材料与结构技术
As the crack nucleation life of cast Al-Si alloy under high-cycle fatigue (HCF) condition is difficult to predict, a finite element analysis of a reference volume element containing a pore is conducted to examine the impact of pore characteristics on me-chanical response. The relationship between non-local maximum plastic shear strain amplitude (∆γ) and pore characteristics is established. The crack nucleation model is developed to predict of crack nucleation life of cylinder head. The results show a high degree of stress concentration degree at the local complex concave and convex positions. The size is main factor affecting pore harmfulness. The ∆γ increases at an accelerated rate with the increase of pore size. The crack nucleation model driven by ∆γ can be used to predict the HCF life within a ±2.5 band error. The high-stress region in the cylinder head is primarily located at the bottom plate, the inlet and exhaust walls. The combination of high stress and large pores contributes to the low HCF life of the inlet surface.
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