【作者】 蒲泽林；

【导师】 杨昆； 刘宗德；

【作者基本信息】 华北电力大学 ， 热能工程， 2001， 硕士

【摘要】 联轴器螺栓是汽轮机的重要部件之一。国内外曾多次发生联轴器螺栓断裂事故，甚至导致机毁人亡的灾难。因此，有必要加强对螺栓的寿命管理。目前，40CrNiMoA材料正被各厂家广泛使用。然而，研究该种材料疲劳特性的工作还开展得较少。本文在试验的基础上，对该材料的常温疲劳特性进行了研究。主要工作如下： 1、利用CSS-280 100KN电液伺服试验机对40CrNiMoA螺栓材料在常温下进行了低周轴向疲劳试验，获得了该材料的循环应力-应变参数和疲劳寿命特性参数，并给出了在不同存活率下的疲劳寿命曲线。 2、利用MTS拉-扭电液伺服试验机对40CrNiMoA材料在常温下进行了剪切疲劳试验，得到了材料的剪切循环应力-应变特性参数和应变疲劳寿命特性参数，并给出了在不同存活率下的剪应变疲劳寿命曲线。 3、利用现有多轴疲劳寿命模型将轴向疲劳和剪切疲劳有机地联系起来，讨论了几种不同寿命预测模型的精度。在轴向疲劳和扭转疲劳的实验结果基础上，提出了基于剪切形式的预测模型。实验证明：该模型与实验数据拟合较好，具有很高的精度。从而，得到了多轴疲劳寿命预测模型。更多还原

【Abstract】 Coupling bolt is one of the important components for the steam turbogenerator. Many catastrophes are caused by the failure of the coupling bolt. So it is necessary to impose the life management for the bolt. The material, 4OCrNiMoA, is now widely used by lots of manufactories. However, the fatigue behaviors of the material have poorly studied. The fatigue behaviors of 4OCrNiMoA are studied experimentally in this paper. The main work is as follows: 1 .The axial LCF experiments at room temperature in air on solid circular specimens of 4OCrNiMoA are performed, using the CSS-280 electric-hydraulic servo-controlled fatigue testing machine. Fatigue parameters of the material including cyclic stress-strain parameters and strain-life parameters are given in this paper. 2.The torsional LCF experiments under the same conditions on thin-walled tubular specimens of the material are performed, using the tension-torsion testing machine. Torsional fatigue parameters including cyclic stress-strain parameters and strain-life parameters are also given. 3.Several multiaxial fatigue life models are used to correlate the torsional fatigue and tensional fatigue. The precisions of these different models are discussed. The model based on torsion is presented by the experiments. ft is proved that this model has high precision. So multiaxial life model is found. Author: Pu Zelin (Thermal Engineering)Directedby: Kun Yang, ProfZongde Liu, Prof更多还原