西安石油大学：《过程设备设计基础 Basic Theory and Design of Process Equipments》课程教学资源（电子课件）第四章 压力容器设计 Design of Pressure Vessel 4.5 疲劳分析（Fatigue Analysis）

第四章 压力容器设计 CHAPTER IV Design of Pressure Vessel 4.5疲劳分析(Fatigue Analysis) 1

1 4.5
 Fatigue Analysis
 CHAPTER Design of Pressure Vessel

过程设备设计 4.1概述 4.2设计准则 4.5.1概述 4.3常规设计 4.5.2低循环疲劳曲线 4.5.3压力容器的疲劳设计 4.4分析设计 4.5.4影响疲劳寿命的其它 因素 4.5疲劳分析 4.6压力容器设计技术进展 2

2 4.1
4.2  4.3  4.4  4.5  4.6  4.5.1
4.5.2  4.5.3  4.5.4  !"


4.5.1 Introduction 过程设备设计 4.5 Fatigue Analysis 教学重点: 压力容器的疲劳设计。 教学难点: 低循环疲劳曲线

3 4.5.1 Introduction
 4.5 Fatigue Analysis
   
 

4.5.1 Introduction 过程设备设计 4.5 Fatigue Analysis 4.5.1 Introduction Causes for the increase of fatigue failure of pressure vessels: I (1) Increase of fatigue loadings; (2) Use of high strength materials Characteristics of fatigue failure: (1) No obvious plastic deformation; (2) Low stress level )Originating from the high stressed zone

4 4.5.1 Introduction
 4.5 Fatigue Analysis 4.5.1 Introduction Causes for the increase of fatigue failure of pressure vessels: (1) Increase of fatigue loadings; (2) Use of high strength materials Characteristics of fatigue failure: (1) No obvious plastic deformation; (2) Low stress level; (3) Originating from the high stressed zone

4.5.1 Introduction 过程设备设计 Parameters to describe fatigue loading: maximum stress minimum stress o max min mean stress alternating stress amplitud o a stress ratio R nax Imin max O+0 R max min max R=-1 or Om=0 complete reversed fatigue; R=0 or 0 pulsative fatigue; mIn R=+1 or min static load

5 4.5.1 Introduction
 Parameters to describe fatigue loading: maximum stress σ max minimum stress σ min mean stress σ m alternating stress amplitudeσ a stress ratio R ( ) 21 σ m = σ max + σ min ( ) 21 σ a = σ max −σ min σ max = σ m + σ a min max R = σ /σ R = −1 or σ m = 0 complete reversed fatigue
R=0 or σ min = 0 pulsative fatigue
R=+1 or σ min = σ max static load.