Analysis and verification of fracture mechanics criteria for a large monobloc high pressure vessel

1982 ◽  
Vol 4 (2) ◽  
pp. 92-98
Author(s):  
R. J. Bishop ◽  
A. K. Khare ◽  
G. J. Mraz
Author(s):  
Yu Xu ◽  
Kuao-John Young

Small size longitudinal holes are common in components of high pressure vessels. In fracture mechanics evaluation, longitudinal holes have not drawn as much attention as cross-bores. However, longitudinal holes become critical at certain locations for such assessments because of high stress concentration and short distance to vessel component wall. The high stress concentration can be attributed to three parts: global hoop stress that is magnified by the existence of the hole, local stresses due to pressure in the hole, and crack face pressure. In high pressure vessel design, axisymmetric models are used extensively in stress analyses, and their results are subsequently employed to identify critical locations for fracture mechanics evaluation. However, axisymmetric models ignore longitudinal holes and therefore cannot be used to identify the critical location inside the holes. This paper is intended to highlight the importance of including longitudinal holes in fracture mechanics evaluation, and to present a quick and effective way of evaluating high stress concentration at a longitudinal hole using the combined analytical solutions and axisymmetric stress analysis results, identifying critical locations and conducting fracture mechanics evaluation.


2008 ◽  
Vol 33-37 ◽  
pp. 79-84 ◽  
Author(s):  
Indera Sadikin ◽  
Djoko Suharto ◽  
Bangkit Meliana ◽  
Kemal Supelli ◽  
Abdul Arya

The use of High-pressure Vessel in eco-friendly Natural Gas Vehicles (NGV) is technologically feasible nowadays. Common applications of High-pressure Vessel are to carry Compressed Natural Gas (CNG), hydrogen for fuel-cell vehicle, and high-compression air in the new air-car technology. High-pressure Vessel is subjected to extreme compression-decompression cycles that could cause fatigue failure. Therefore, vessel shall be inspected regularly to detect if there is crack inside. The objective of this paper is to optimize the inspection interval of CNG Highpressure Vessel by means of Probabilistic Fracture Mechanics Analysis. Vessel is made of highalloy steel and assumed to have distributed elliptical cracks. Three length-to-depth crack ratios (a/c), i.e. 3, 8, and 15, are simulated. Crack is assumed to propagate in fixed ratio. Stress Intensity Factors at each crack tip are calculated by Finite Element Analysis and Crack Closure Technique. Fatigue crack growth is simulated by Cycle-by-Cycle Integration Technique. The Fracture Mechanics Analysis is then expanded to probabilistic analysis by considering stochastic nature of analysis parameters. Probability of failure is computed by Guided Direct Simulation Method using software which is specially written for this project [1]. Based on simulation result, High-pressure Vessel is recommended to be inspected every 3 years.


Author(s):  
Xin Ma ◽  
Zhongpei Ning ◽  
Honggang Chen ◽  
Jinyang Zheng

Ultra-High Pressure Vessel (UHPV) with self-protective Flat Steel Ribbons (FSR) wound and Tooth-Locked Quick-Actuating (TLQA) end closure is a new type of vessel developed in recent years. When the structural parameters of its TLQA and Buttress Thread (BT) end closure are determined using the ordinary engineering design method, Design by Analysis (DBA) shows that the requirement on fatigue life of this unique UHPV could hardly be satisfied. To solve the above problem, an integrated FE modeling method has been proposed in this paper. To investigate the fatigue life of TLQA and BT end closures of a full-scale unique UHPV, a three-dimensional (3-D) Finite Element (FE) solid model and a two-dimensional (2-D) FE axisymmetric model are built in FE software ANSYS, respectively., Nonlinear FE analysis and orthogonal testing are both conducted to obtain the optimum structure strength, in which the peak stress in the TLQA or BT end closure of the unique UHPV is taken as an optimal target. The important parameters, such as root structure of teeth, contact pressure between the pre-stressed collar and the cylinder end, the knuckle radius, the buttress thread profile and the local structure of the cylinder, are optimized. As a result, both the stress distribution at the root of teeth and the axial load carried by each thread are improved. Therefore, the load-carrying capacity of the end closure has been reinforced and the fatigue life of unique UHPV has been extended.


2011 ◽  
Vol 213 ◽  
pp. 241-245
Author(s):  
Hong Wang ◽  
Yu Xian Zhang ◽  
Qing Xia Lin ◽  
Qing Hua Zhou

In order to study the residual stress of the auto-frettagea super high pressure vessel effectively, a new stress and strain analytical formula is brought forward. It indicates that this analytical formula is more accurate under actual conditions for the steel applied in auto-frettagea super high pressure vessel through strict mathematical testimony. Subsequently, it describes how to establish this analytical formula and analyzes the analytical formula’s error through taking some material as an example. It illustrates that it is feasible and reliable to solve this new analytical formula basing on general tensile curves through this instance. The analytical formula is also of theoretical signification and engineering practical value in application.


Author(s):  
Xin Ma ◽  
Jinyang Zheng ◽  
Zhongpei Ning ◽  
Honggang Chen

A unique type of self-protective Ultra-High Pressure Vessel (UHPV) cylinder with helically wound Flat Steel Ribbons (FSR) is proposed. The shielding properties of its self-protection in the hoop and axial directions of a FSR cylinder in the case of fracture failure, as well as quick-actuating of the tooth-locked end closure of this new vessel structure are both expounded. Based on its axial strength, a formula of the ultimate load-carrying capability of FSR layers is derived. The shielding function and self-protective capability of FSR layers to the UHPV cylinder are analyzed quantitatively in detail, and a design criterion is also defined. According to the formula and the design criterion defined in this paper, the predicted ultimate load-carrying capability of the FSR layers is 48.3% higher than that in previous references. Results from burst tests of 6 model vessels show that the brittle failure morphology of UHPV cylinders are changed with FSR layers and the potential hazard of failure of the UHPV is reduced. In addition, the cross fracture of the UHPV cylinder is shielded effectively and the derived formulation on the ultimate load-carrying capability of FSR layers is reasonable. UHPV cylinders designed according to the formula and the criterion can use much fewer FSR layers with the same shielding capability.


Author(s):  
Zhiwei Chen ◽  
Tao Li ◽  
Guoyi Yang ◽  
Jinyang Zheng ◽  
Guide Deng

Abstract GB/T 34019-2017 “Ultra High Pressure Vessels” is the most important national standard that applies to pressure vessel which design pressure value is greater than or equal to 100MPa (14.5ksi). There is no standard for Ultra-high Pressure Vessel, Then this standard fills the gap in the standard system of pressure equipment in China. This paper mainly introduces the concept and main content of the new national standard, including the materials, design methods and nondestructive testing of ultra-high pressure vessel.


Author(s):  
David Fuenmayor ◽  
Rolf Wink ◽  
Matthias Bortz

There are numerous codes covering the design, manufacturing, inspection, testing, and operation of pressure vessels. These national or international codes aim at providing assurance regarding the safety and quality of pressure vessels. The development of the Chinese economy has led to a significant increase in the number of installed high-pressure vessels which in turn required a revision of the existing regulations. The Supervision Regulation on Safety Technology for Stationary Pressure Vessel TSG 21-2016 superseded the existing Super-High Pressure Vessel Safety and Technical Supervision Regulation TSG R0002-2005 in October of 2016. This new regulation covers, among others, the design, construction, and inspection of pressure vessels with design pressures above 100 MPa. This paper provides a technical comparison between the provisions given in TSG 21-2016 for super-high pressure vessels and the requirements in ASME Boiler and Pressure Vessel Code Section VIII Division 3.


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