第四章 压力容器设计 CHAPTER IV Design of Pressure Vessel 4.4分析设计(Design by Analysis) 1
1 4.4 Design by Analysis CHAPTER Design of Pressure Vessel
过程设备设计 4.4.1概述 4.1概述 4.4.2压力容器的应力分类 4.2 设计准则 4.4.3应力强度计算 4.4.4应力强度限制 4.3常规设计 4.4.5分析设计的应用 4.4分析设计 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 4.4.3 4.4.4 4.4.5 4.4.2 4.4.1
4.4.1 Introduction 过程设备设计 4.4 Design by Analysis 教学重点: 压力容器的应力分类 教学难点: 应力强度计算。 3
3 4.4.1 Introduction 4.4 Design by Analysis
4.4.1 Introduction 过程设备设计 4.4 Design by analysis Design of pressure vessels Design- Design-by- analysIs GB150《 Steel JB4732 Steel Pressure Pressure Vessels》 Ⅴ essels--Code Design by Analysis》
4 4.4.1 Introduction 4.4 Design by Analysis Design of pressure vessels Designby-rule Design-by- analysis GB150 Steel Pressure Vessels JB4732 Steel Pressure Vessels—Code for Design by Analysis
4.4.1 Introduction 过程设备设计 4.4.1 Introduction Limitations of design-by-rule: (1)Loadings Loadings Design-by-rule Design-by- analysIS Static C yclIc (2) Stress calculation Stress calculation Design-by-rule Design-by-analysis Si Analytic, numerical, Methods Imple experimental formulas method Places Shell All points
5 4.4.1 Introduction 4.4.1 Introduction Limitations of design-by-rule: 1!Loadings Cyclic × Static Design-byanalysis Loadings Design-by-rule 2!Stress calculation Places Shell All points Analytic, numerical, experimental method Simple formulas Methods Stress calculation Design-by-rule Design-by-analysis
4.4.1 Introduction 过程设备设计 Limitations of design-by-rule (3) Pressure vessel structures Codes Design-by-rule Design-by-analysis Structures Some structures Any structures Philosophy of design-by-analysis (1) Different types of stress have different degrees of importance to pressure vessels (2) If a proper stress analysis can be conducted, a better, less conservative design of pressure vessels can be made
6 3!Pressure vessel structures Structures Some structures Any structures Codes Design-by-rule Design-by-analysis Limitations of design-by-rule: Philosophy of design-by-analysis 2!If a proper stress analysis can be conducted, a better, less conservative design of pressure vessels can be made. 1!Different types of stress have different degrees of importance to pressure vessels; 4.4.1 Introduction
4. 4.2 Stress categories of Pressure vessels 过程设备设计 4.4.2 Stress Categories of Pressure Vessels 4.4.2.1 Stress Categories Basis for stress category: hazards to pressure vessels Determining factors (1)location and distribution (2) types of loading Major stress categories: primary, secondary, peak
7 4.4.2 Stress Categories of Pressure Vessels 4.4.2 Stress Categories of Pressure Vessels 4.4.2.1 Stress Categories Basis for stress category: hazards to pressure vessels Determining factors: (1) location and distribution; (2) types of loading Major stress categories: primary, secondary, peak
4. 4.2 Stress categories of Pressure vessels 过程设备设计 Primary stress(P: Definition: developed by the imposed loading; necessary to satisfy the laws of equilibrium between external and internal forces and moments Basic characteristic: not self-limiting Sub-categories: general primary membrane stress (Pm), local primary membrane stress(PL), primary bending stress(Pb)
8 4.4.2 Stress Categories of Pressure Vessels Definition: developed by the imposed loading; necessary to satisfy the laws of equilibrium between external and internal forces and moments Basic characteristic: not self-limiting Sub-categories: general primary membrane stress (Pm), local primary membrane stress (PL), primary bending stress (Pb) Primary stress (P):
4. 4.2 Stress categories of Pressure vessels 过程设备设计 Primary stress Membrane Bending(Pb) G eneral ( n oca general primary Examples of a local An example is membrane is the one that is primary membrane the bending so distributed in the structure stress are the stress in the that no redistribution of load membrane stress in a central portion occurs as a result of yielding. produced byof a flat head An example is the stress in a external load and the due to pressure circular cylindrical shell due moment at a permanent to internal pressure. support or at a nozzle connection
9 4.4.2 Stress Categories of Pressure Vessels Bending (Pb) An example is the bending stress in the central portion of a flat head due to pressure. Primarystress Membrane General (Pm) Local (PL) A general primary membrane is the one that is so distributed in the structure that no redistribution of load occurs as a result of yielding. An example is the stress in a circular cylindrical shell due to internal pressure. Examples of a local primary membrane stress are the membrane stress in a shell produced by external load and the moment at a permanent support or at a nozzle connection.
4. 4.2 Stress categories of Pressure vessels 过程设备设计 Secondary stress(O Definition: developed by the self-constrained of a structure Basic characteristic: self-limiting Peak stress(Fl Definition: highest stress in the region under consideration Basic characteristic: causing no significant distortion; a possible source of fatigue failure
10 4.4.2 Stress Categories of Pressure Vessels Definition: highest stress in the region under consideration Basic characteristic: causing no significant distortion; a possible source of fatigue failure Secondary stress (Q) Definition: developed by the self-constrained of a structure Basic characteristic: self-limiting Peak stress (F)