本文通过试验分析了灰铸铁的同相和异相热疲劳及C-P型和P-C型高温低周疲劳特性,并应用弹塑性断裂力学方法对其寿命作了解析评价。试验和计算都表明,在相同应变范围下,同相和C-P型疲劳寿命分别高于异相和P-C型。这与低碳钢等材料结果相反。另外,计算值和试验吻合,说明J积分用作评价灰铸铁热疲劳强度的力学参量及本文所建立的力学模型和计算方法有效。文中从能量角度提出了一个用于描述裂纹扩展能力的参量ΔW_T,在相同ΔW_T值下,高温低周疲劳寿命和热疲劳相等。
The in-phase and out-of-phase therznal fatigue, the C-P type and P-Ctype isothermal fatigue of grey cast iron were experimentally studied. The fatiguelife was evaluated analytically by using the elastic-plastic fracture mechanics method(mainly J integral). The results of experiments and calculations showed that thelife of in-phase and C-P type fatigue are longer than that of out-of-phase and P-Ctype fatigue respectively within the same strain range. This is in contrast toresults of other materials such as low carbon steel. On the other hand, the predicted life are consistent with experimental results. This suggests that J integral asa mechanics parameter for characterizing the thermal fatigue strength of grey castiron and the mechanics model and calculation method developed here are efficient.A parameter △W_t was proposed from energy aspect to characterize the capacityof crack propagation. The isothermal fatigue life is the same as the thermal fatiguelife for identical △W_t values.
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| [1] | |
| [2] | |
| [3] | |
| [4] | |
| [5] | |
| [6] |
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