Probabilistic Fracture Mechanics Analysis for Optimization of High-Pressure Vessel Inspection

2008 ◽  
Vol 33-37 ◽  
pp. 79-84 ◽  
Author(s):  
Indera Sadikin ◽  
Djoko Suharto ◽  
Bangkit Meliana ◽  
Kemal Supelli ◽  
Abdul Arya
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Fracture Mechanics ◽  
Pressure Vessel ◽  
Fixed Ratio ◽  
Fuel Cell Vehicle ◽  
Element Analysis ◽  
High Pressure Vessel ◽  
Probabilistic Fracture Mechanics ◽  
Mechanics Analysis

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.

scholarly journals Recent verification activities on probabilistic fracture mechanics analysis code PASCAL4 for reactor pressure vessel

2020 ◽  
Vol 7 (3) ◽  
pp. 19-00573-19-00573
Author(s):  
Kai LU ◽  
Jinya KATSUYAMA ◽  
Yinsheng LI ◽  
Yuhei MIYAMOTO ◽  
Takatoshi HIROTA ◽  
...  
Keyword(s):  
Fracture Mechanics ◽  
Pressure Vessel ◽  
Reactor Pressure Vessel ◽  
Probabilistic Fracture Mechanics ◽  
Mechanics Analysis ◽  
Reactor Pressure

Fracture Assessments of High Pressure Vessel Components Having Longitudinal Holes

2017 ◽  
Author(s):  
Yu Xu ◽  
Kuao-John Young
Keyword(s):  
High Pressure ◽  
Stress Concentration ◽  
Fracture Mechanics ◽  
Pressure Vessel ◽  
High Stress ◽  
Pressure Vessels ◽  
Crack Face ◽  
High Pressure Vessel ◽  
High Stress Concentration ◽  
Critical Locations

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.

Development of Probabilistic Fracture Mechanics Analysis Codes for Reactor Pressure Vessels Considering Recent Embrittlement Model and Calculation Method of SIF: Progress of the Work

2016 ◽  
Author(s):  
Jongmin Kim ◽  
Bongsang Lee ◽  
Taehyun Kim ◽  
Yoonsuk Chang
Keyword(s):  
Stress Intensity ◽  
Fracture Mechanics ◽  
Pressure Vessel ◽  
Calculation Method ◽  
Reactor Pressure Vessel ◽  
Radiation Embrittlement ◽  
Calculation Methods ◽  
Probabilistic Fracture Mechanics ◽  
Mechanics Analysis ◽  
Reactor Pressure

It is widely recognized that the state of knowledge and data for the probabilistic calculations which had been proposed in the early 1980s made a conservative treatment of several key factors and models. Recently, applications of some new radiation embrittlement model, material database, calculation method of stress intensity factors and others which can improve fracture mechanics assessment of reactor pressure vessel (RPV) are introduced. This improvement on the accuracy and reliability of the probabilistic fracture mechanics (PFM) analysis necessitated changes in PFM analysis procedures and calculations. Modification and application of newly developed models and calculation methods are the main target of developing a probabilistic fracture mechanics analysis code based on the structure of existing R-PIE and VISA computer code to reflect the latest technical basis. Failure probabilities of reactor pressure vessel under pressurized thermal shock (PTS) conditions were calculated through finite difference method (FDM) and Monte Carlo simulation techniques with user friendly graphic interface. Moreover, various radiation embrittlement models and calculation methods of stress intensity factor at crack tip based on AFCEN code are applied and verified in the present work.

Sign in / Sign up

Export Citation Format

Share Document