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Shinobu Yoshimura - One of the best experts on this subject based on the ideXlab platform.
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benchmark analysis on Probabilistic Fracture Mechanics analysis codes considering multiple cracks and crack initiation in aged piping of nuclear power plants
ASME 2014 Pressure Vessels and Piping Conference, 2014Co-Authors: Kazuya Osakabe, Kunio Onizawa, Jinya Katsuyama, Genshichiro Katsumata, Shinobu YoshimuraAbstract:In recent years, cracks have been detected in piping systems of nuclear power plants. Many of them are multiple cracks in the same welded joints. Therefore, structural integrity evaluation and risk assessment considering multiple cracks and crack initiation in aged piping have become increasingly important. Probabilistic Fracture Mechanics (PFM) is a rational methodology in structural integrity evaluation and risk assessment of aged piping in nuclear power plants. Two PFM codes, PASCAL-SP and PRAISE-JNES, have been improved or developed in Japan for the structural integrity evaluation and risk assessment considering the age related degradation mechanisms of pipes. Although the purposes to develop these two codes are different, both have almost the same basic functions to obtain the failure probabilities of pipes. In this paper, a benchmark analysis was conducted considering multiple cracks and crack initiation, in order to confirm their reliability and applicability. Based on the numerical investigation in consideration of important influence factors such as crack number, crack location, crack distribution and crack detection probability of in-service inspection, it was concluded that the analysis results of these two codes are in good agreement.Copyright © 2014 by ASME
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Benchmark analysis on Probabilistic Fracture Mechanics analysis codes concerning fatigue crack growth in aged piping of nuclear power plants
International Journal of Pressure Vessels and Piping, 2014Co-Authors: Jinya Katsuyama, Kunio Onizawa, Hiroto Itoh, Kazuya Osakabe, Shinobu YoshimuraAbstract:Abstract Probabilistic Fracture Mechanics (PFM) is a rational methodology in structural integrity evaluation and risk assessment of aged piping in nuclear power plants. Several PFM analysis codes have been improved or developed in Japan, such as PRAISE-JNES and PASCAL-SP. Although they were developed for different purposes, some basic functions are almost the same. In this paper, in order to confirm the reliability and applicability of two PFM analysis codes, PRAISE-JNES and PASCAL-SP, a benchmark analysis is carried out using the basic functions in these two codes, considering representative piping systems in nuclear power plants and fatigue as the typical aging mechanisms. We discussed the reliability and applicability of these codes based on a previously proposed criterion to judge quantitatively whether the differences between the analysis results from two PFM analysis codes can be acceptable. Through the benchmark analysis, it is concluded that the analysis results of these two codes are in good agreements quantitatively.
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benchmark analysis and numerical investigation on Probabilistic Fracture Mechanics analysis codes for npps piping
International Journal of Pressure Vessels and Piping, 2012Co-Authors: Hiroto Itoh, Kunio Onizawa, Kazuya Osakabe, Shinobu YoshimuraAbstract:Abstract In this paper, a benchmark analysis was conducted using two Probabilistic Fracture Mechanics analysis codes for aged piping in nuclear power plants, in order to confirm their reliability and applicability. These analysis codes have been improved or developed in Japan for the structural integrity evaluation and risk assessment considering the age related degradation mechanisms. In the benchmark analysis, the primary loop recirculation system piping in the boiling water reactor was selected as the typical piping system and stress corrosion cracking and fatigue were taken into account as the typical aging mechanisms. Moreover, a criterion was proposed for judging whether the differences between analysis results from the two codes are acceptable. This criterion is useful for general benchmark analysis of Probabilistic Fracture Mechanics analysis codes. Based on the benchmark analysis results and numerical investigation, it was concluded that the analysis results of these two codes agree very well.
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recent japanese research activities on Probabilistic Fracture Mechanics for pressure vessel and piping of nuclear power plant
International Journal of Pressure Vessels and Piping, 2010Co-Authors: Y Kanto, Kunio Onizawa, Hideo Machida, Y Isobe, Shinobu YoshimuraAbstract:Abstract This paper describes a review of recent Japanese activities on Probabilistic Fracture Mechanics (PFM) analyses. Japan Atomic Energy Agency (JAEA: previously JAERI) had sponsored research committees on PFM organized by Japan Society of Mechanical Engineers (JSME) and Japan Welding Engineering Society (JWES) for more than a decade. This work still continues with the same members in JWES. The purpose of the continuous activity is to provide Probabilistic approaches in several fields of integrity problems of nuclear power plant. This paper shows some of the newest results of the JWES research committee. First topic is evaluation of the new JSME code case with rules of Fitness-For-Service from the view of PFM, including reactor pressure vessel subject to pressurized thermal shock loading, piping with a crack of the allowable size and effect of sizing accuracy for piping integrity. The next one is development of new PFM techniques including reliability assessment of piping with domestic (Japanese) SCC data and maintenance optimization of LWRs based on risk and economic models. The last topic is the international round robin program just starting from 2008.
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development of Probabilistic Fracture Mechanics analysis code for pipes with stress corrosion cracks
Journal of Power and Energy Systems, 2009Co-Authors: Hideo Machida, Manabu Arakawa, Norimichi Yamashita, Shinobu YoshimuraAbstract:Risk-Informed integrity management methodologies have been developed for Japanese nuclear power plants. One of the issues of concern is the reliability assessment of piping with flaws due to stress corrosion cracking (SCC). Therefore, the Probabilistic Fracture Mechanics analysis code has been developed, which can perform the reliability assessment for austenitic stainless steel piping with flaws due to SCC. This paper describes technical basis of this code. This method is based on Monte-Carlo technique considering many sample cases in a piping section, where the initiation and growth of cracks are calculated and piping failures, including leaks and rapture, are evaluated. A notable feature is that multiple cracks can be treated, consequently, assessment of coalescence of cracks and intricate break evaluation of piping section have been included. Moreover, the in-service inspection (ISI) and integrity evaluation by Fitness-for-Service (FFS) code are integrated into the analysis, and the contribution to failure probability decrease can be assessed. Key parameters are determined on a probability basis with the designated probability type throughout the procedure. Size, location and time of crack initiation, coefficients of crack growth due to SCC and factors for piping failure are included in those parameters. With this method the reliability level of the piping through the operation periods can be estimated and the contribution of various parameters including ISI can be quantitatively evaluated.
Genki Yagawa - One of the best experts on this subject based on the ideXlab platform.
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economic evaluation of maintenance strategies for steam generator tubes using Probabilistic Fracture Mechanics and a financial method
Solid State Phenomena, 2007Co-Authors: Yoshihiro Isobe, Shinobu Yoshimura, Mitsuyuki Sagisaka, Genki YagawaAbstract:As an application of Probabilistic Fracture Mechanics (PFM) and a financial method, a risk-benefit model was developed for the purpose of optimizing maintenance activities of steam generator (SG) tubes used in pressurized water reactors (PWRs). To justify whether or not it is worth while implementing the selected maintenance strategy in terms of an economic point of view, net present value (NPV) was calculated as an index which is one of the most fundamental financial indices for decision-making based on the discounted cash flow (DCF) method.
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recent japanese Probabilistic Fracture Mechanics researches related to failure probability of aged rpv
Solid State Phenomena, 2007Co-Authors: Katsuyuki Shibata, Shinobu Yoshimura, Yasuhiro Kanto, Genki YagawaAbstract:In order to prepare for the need of Probabilistic methodology in design, inspection and maintenance of nuclear components, JAERI (The Japan Atomic Energy Research Institute) has conducted PFM (Probabilistic Fracture Mechanics) researches of Phase 1 and Phase 2 since late 1980s. In order to establish the standard procedure, Phase 1 had been conducted from 1988 to 1994 by entrusting contract researches to JWES (The Japan Welding Engineering Society), MRI (Mitsubishi Research Institute Incorporation) and JSME (The Japan Society of Mechanical Engineers). Subsequently, JAERI initiated Phase 2 in 1996 aiming at more practical application. JAERI had entrusted contract researches from 1996 to 2000 to JWES. JAERI also initiated a development of a PFM Code PASCAL (PFM Analysis of Structural Components in Aging LWR) as well as the contract research. The development of PASCAL-Ver.1 was completed in 2000. PASCAL-Ver.1 was released in 2001. Using PASCAL-Ver. 1, round robin analyses on the usability of the code, the effect of annealing on the failure probability of an RPV, the Probabilistic evaluation of the flaw acceptance standard in ASME ( or JSME) Code have been performed within the contract research. This paper presents the overview of activities related to RPV and some results of round robin analyses conducted in PFM Sub-Committee in JWES. In addition, the outline of PASCAL-Ver.1 is also introduced.
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optimization of operation and maintenance of nuclear power plant by Probabilistic Fracture Mechanics
Nuclear Engineering and Design, 2002Co-Authors: Noriyoshi Maeda, Genki Yagawa, Shinichi Nakagawa, Shinobu YoshimuraAbstract:Abstract Maintenance activity including inspection, repair and replacement is regarded as the most important key factor for the safety, reliability and economy of a nuclear power plant. The decision making—what kind of and to what extent maintenance should be performed—has to be done based on the evaluation of contribution to not only safety and reliability but also economy during long life time, taking such issues as aging and life extension into consideration. More economical operation of nuclear power plants can be attained not only by reducing the above mentioned costs but by increasing generation of electricity for which increase of total amount of thermal output and improvement of conversion ratio from thermal output to electricity may play important role. Increasing the flow rate of coolant or shifting higher the operational temperature and pressure may serve as candidates for a measure to increase thermal output. It is generally recognized that increasing of power generation may accelerate degradation of components. This means that increasing of power generation can be attained by performing better maintenance which may cost more, as the acceleration of degradation may increase the probability of accident. Following evaluations are performed in this study. Expectation value of cost of countermeasure for accident, expectation value of cost to repair the weld where defects are detected through ISI and cost for inspection are calculated as function of inspection frequency. The optimization of inspection frequency can be attained by finding the frequency where sum of these three costs takes minimum value. By selecting profit as object function, trial calculation for optimization of operation and maintenance of nuclear power plant was performed through calculation of costs for maintenance and electricity generation as function of inspection frequency and operational temperature following the Probabilistic Fracture Mechanics principle. Through the calculation, several problems including identification of degradation for each material are revealed which may serve to make such calculation more realistic and useful when used in nuclear power plant.
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Probabilistic Fracture Mechanics analysis of nuclear structural components a review of recent japanese activities
Nuclear Engineering and Design, 2001Co-Authors: Genki Yagawa, Shinobu Yoshimura, Hideo Machida, Yasuhiro Kanto, Katsuyuki ShibataAbstract:This paper describes a review of recent Japanese activities on Probabilistic Fracture Mechanics (PFM) analyses. Japan Atomic Energy Research Institute (JAERI) has sponsored research committees on PFM organized by Japan Society of Mechanical Engineers (JSME) and Japan Welding Engineering Society (JWES) for more than 10 years. The purpose of the continuous activity is to establish standard procedures for evaluating failure probabilities of Japanese nuclear structural components such as PV&P and steam generator tube, combining the state-of-the-art knowledge on structural integrity of nuclear structural components and modern computer technology such as parallel processing. This paper shows two topics of the newest results of JWES committee, PFM analysis of aged reactor pressure vessel considering embedded cracks and PFM analysis of piping considering seismic loading, and one topic by JAERI itself, development of PTS analysis code for transient loading (PASCAL).
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risk benefit analyses of sg tube maintenance based on Probabilistic Fracture Mechanics
Nuclear Engineering and Design, 2001Co-Authors: Y Isobe, Shinobu Yoshimura, Mitsuyuki Sagisaka, Genki YagawaAbstract:Abstract As an application of Probabilistic Fracture Mechanics (PFM), a risk–benefit analysis was performed for the purpose of optimizing maintenance activities of steam generator (SG) tubes used in pressurized water reactors (PWRs). The probabilities of the SG tube leakage and rupture are defined as risks in this study. A model was made modifying pc-PRAISE (Piping Reliability Analysis Including Seismic Events) to evaluate the risks during 60 year operations due to stress corrosion cracking (SCC) of the tubes under various maintenance strategies for SG tubes. In the risk analysis, parameters such as inspection accuracy, inspection interval, sampling inspection and crack propagation law were selected for sensitivity analysis. Based on the risk analysis, a risk–benefit analysis was conducted when implementing two maintenance strategies taking both costs and revenues for 60 year operations into account. In the risk–benefit analysis, the expected cost of leakage or rupture was calculated by multiplying ‘probability of leakage or rupture’ by ‘expected loss of leakage or rupture accident’. To justify whether it is worthwhile implementing the maintenance strategies or not, the net present value (NPV) was calculated as an index, which is one of the most fundamental financial indices for decision-making based on the discounted cash flow (DCF) method. The results demonstrated that in the risk analysis, the risks are influenced significantly by the crack propagation law, accuracy of inspection and sampling inspection. In the risk–benefit analysis, it was suggested that investment to improve inspection accuracy would reduce the total costs of 60 year operations significantly and increase the NPV. Although the analysis was mainly conducted for SG tubes made of Inconel 600 mill anneal (MA) material, the analysis was also carried out for Inconel 690 thermal treatment (TT) material, making assumptions on its crack initiation and crack propagation law. In addition, the effect of introducing maintenance criteria, namely, operation with a crack justified by certain criteria, on NPV was evaluated.
Wei Gao - One of the best experts on this subject based on the ideXlab platform.
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stochastic response analysis of the scaled boundary finite element method and application to Probabilistic Fracture Mechanics
Computers & Structures, 2015Co-Authors: X Y Long, C Jiang, X Han, Wei GaoAbstract:We propose an efficient stochastic response analysis method for the SBFEM.We give an improved approach to compute the sensitivities of the SBFEM responses.Semi-analytical evaluation of the displacement, stress and the SIFs derivatives.The stochastic analysis of the orthotropic and cracked structures is performed.Reliability analysis is efficiently performed without iteration. This paper proposes a stochastic response analysis method for the scaled boundary finite element method (SBFEM), through which the statistical characteristics of the structural responses subject to random uncertainty can be efficiently calculated. In the proposed method, an approximate approach is given to solve the first four statistical moments of the random responses of SBFEM. The probability density functions of the structural responses are calculated using the maximum entropy principle constrained by the calculated moments. The semi-analytical gradients of the responses with respect to the random variables are solved by developing an improved sensitivity analysis method of SBFEM. The proposed method is then applied to the structural reliability analysis and the Probabilistic Fracture Mechanics analysis. Four numerical examples are investigated to demonstrate the validity of the proposed method.
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Probabilistic Fracture Mechanics with uncertainty in crack size and orientation using the scaled boundary finite element method
Computers & Structures, 2014Co-Authors: Morsaleen Shehzad Chowdhury, Chongmin Song, Wei GaoAbstract:Abstract The geometry of cracks in a structure are often difficult to determine accurately, leading to uncertainties in structural analysis. This paper presents a Probabilistic Fracture Mechanics (PFM) approach to evaluate the reliability of cracked structures considering the uncertainty in crack geometry. The shape sensitivity analysis of the stress intensity factor (SIF) is performed efficiently using the scaled boundary finite element method (SBFEM). No remeshing is required as the size and orientation of a crack vary. Reliability is estimated using various Probabilistic techniques. Numerical examples demonstrate the accuracy and simplicity of the present method.
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Probabilistic Fracture Mechanics by using monte carlo simulation and the scaled boundary finite element method
Engineering Fracture Mechanics, 2011Co-Authors: Morsaleen Shehzad Chowdhury, Chongmin Song, Wei GaoAbstract:Abstract A numerical technique to model the effect of uncertainties in the crack geometry on the reliability of cracked structures is presented. The shape sensitivity analysis of stress intensity factors to the crack size and orientation is performed by using the scaled boundary finite element method (SBFEM). Only a single boundary mesh is required. The varying crack size and orientation are represented by simply moving the scaling center and without the need for remeshing. The reliability assessment is performed by Monte Carlo simulations. Numerical examples are analyzed to verify the accuracy and demonstrate the efficiency and simplicity of the proposed technique.
Kunio Onizawa - One of the best experts on this subject based on the ideXlab platform.
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IMPROVEMENT OF Probabilistic Fracture Mechanics ANALYSIS CODE FOR REACTOR PIPING CONSIDERING LARGE EARTHQUAKES
2020Co-Authors: Yoshihito Yamaguchi, Kunio Onizawa, Jinya Katsuyama, Makoto Udagawa, Yutaka NishiyamaAbstract:ABSTRACT The Probabilistic Fracture Mechanics analysis code PASCAL-SP is improved by introducing crack-growth evaluation methods based on J-integrals, including calculation functions of J-integral values for semi-elliptical surfaces and through-wall cracks in pipes. Using the improved PASCAL-SP, sensitivity analyses that varied parameters such as earthquake magnitude were carried out on the basis of Probabilistic evaluation. Results obtained from sensitivity analyses are also presented, e.g., the effect of earthquake magnitude on failure probability. The improved PASCAL-SP makes evaluation of the failure probability of piping under large seismic loading possible
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benchmark analysis on Probabilistic Fracture Mechanics analysis codes considering multiple cracks and crack initiation in aged piping of nuclear power plants
ASME 2014 Pressure Vessels and Piping Conference, 2014Co-Authors: Kazuya Osakabe, Kunio Onizawa, Jinya Katsuyama, Genshichiro Katsumata, Shinobu YoshimuraAbstract:In recent years, cracks have been detected in piping systems of nuclear power plants. Many of them are multiple cracks in the same welded joints. Therefore, structural integrity evaluation and risk assessment considering multiple cracks and crack initiation in aged piping have become increasingly important. Probabilistic Fracture Mechanics (PFM) is a rational methodology in structural integrity evaluation and risk assessment of aged piping in nuclear power plants. Two PFM codes, PASCAL-SP and PRAISE-JNES, have been improved or developed in Japan for the structural integrity evaluation and risk assessment considering the age related degradation mechanisms of pipes. Although the purposes to develop these two codes are different, both have almost the same basic functions to obtain the failure probabilities of pipes. In this paper, a benchmark analysis was conducted considering multiple cracks and crack initiation, in order to confirm their reliability and applicability. Based on the numerical investigation in consideration of important influence factors such as crack number, crack location, crack distribution and crack detection probability of in-service inspection, it was concluded that the analysis results of these two codes are in good agreement.Copyright © 2014 by ASME
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Benchmark analysis on Probabilistic Fracture Mechanics analysis codes concerning fatigue crack growth in aged piping of nuclear power plants
International Journal of Pressure Vessels and Piping, 2014Co-Authors: Jinya Katsuyama, Kunio Onizawa, Hiroto Itoh, Kazuya Osakabe, Shinobu YoshimuraAbstract:Abstract Probabilistic Fracture Mechanics (PFM) is a rational methodology in structural integrity evaluation and risk assessment of aged piping in nuclear power plants. Several PFM analysis codes have been improved or developed in Japan, such as PRAISE-JNES and PASCAL-SP. Although they were developed for different purposes, some basic functions are almost the same. In this paper, in order to confirm the reliability and applicability of two PFM analysis codes, PRAISE-JNES and PASCAL-SP, a benchmark analysis is carried out using the basic functions in these two codes, considering representative piping systems in nuclear power plants and fatigue as the typical aging mechanisms. We discussed the reliability and applicability of these codes based on a previously proposed criterion to judge quantitatively whether the differences between the analysis results from two PFM analysis codes can be acceptable. Through the benchmark analysis, it is concluded that the analysis results of these two codes are in good agreements quantitatively.
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benchmark analysis and numerical investigation on Probabilistic Fracture Mechanics analysis codes for npps piping
International Journal of Pressure Vessels and Piping, 2012Co-Authors: Hiroto Itoh, Kunio Onizawa, Kazuya Osakabe, Shinobu YoshimuraAbstract:Abstract In this paper, a benchmark analysis was conducted using two Probabilistic Fracture Mechanics analysis codes for aged piping in nuclear power plants, in order to confirm their reliability and applicability. These analysis codes have been improved or developed in Japan for the structural integrity evaluation and risk assessment considering the age related degradation mechanisms. In the benchmark analysis, the primary loop recirculation system piping in the boiling water reactor was selected as the typical piping system and stress corrosion cracking and fatigue were taken into account as the typical aging mechanisms. Moreover, a criterion was proposed for judging whether the differences between analysis results from the two codes are acceptable. This criterion is useful for general benchmark analysis of Probabilistic Fracture Mechanics analysis codes. Based on the benchmark analysis results and numerical investigation, it was concluded that the analysis results of these two codes agree very well.
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improvement of Probabilistic Fracture Mechanics analysis code pascal2 for reactor pressure vessel focusing on weld overlay cladding
Atomic Energy Society of Japan, 2011Co-Authors: Hiroyuki Nishikawa, Kunio OnizawaAbstract:The Probabilistic Fracture Mechanics analysis code PASCAL2 has been updated by Japan Atomic Energy Agency (JAEA) to support the validation of the codes and standards that provide the structural integrity assessment method of reactor pressure vessels during pressurized thermal shock. In this study, the evaluation methods for flaw initiation considering weld-overlay cladding and nondestructive inspection models and considering the existence of cladding have been improved. Using the improved PASCAL2 code, the effects of flaw initiation, the growth model for a cladding flaw, and the nondestructive inspection model on failure probability have been analyzed. The analysis verifies that the application of the improved flaw initiation model decreases the conditional probability of failure. The result also shows that only the maximum detection probability affects the failure probability among the parameters of the improved nondestructive inspection model.
Sharif Rahman - One of the best experts on this subject based on the ideXlab platform.
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Probabilistic Fracture Mechanics by galerkin meshless methods part ii reliability analysis
Computational Mechanics, 2002Co-Authors: Sharif Rahman, B N RaoAbstract:This is the second in a series of two papers generated from a study on Probabilistic meshless analysis of cracks. In this paper, a stochastic meshless method is presented for Probabilistic Fracture-Mechanics analysis of linear-elastic cracked structures. The method involves an element-free Galerkin method for calculating Fracture response characteristics; statistical models of uncertainties in load, material properties, and crack geometry; and the first-order reliability method for predicting Probabilistic Fracture response and reliability of cracked structures. The sensitivity of Fracture parameters with respect to crack size, required for Probabilistic analysis, is calculated using a virtual crack extension technique described in the companion paper [1]. Numerical examples based on mode-I and mixed-mode problems are presented to illustrate the proposed method. The results show that the predicted probability of Fracture initiation based on the proposed formulation of the sensitivity of Fracture parameter is accurate in comparison with the Monte Carlo simulation results. Since all gradients are calculated analytically, reliability analysis of cracks can be performed efficiently using meshless methods.
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Probabilistic Fracture Mechanics by galerkin meshless methods part i rates of stress intensity factors
Computational Mechanics, 2002Co-Authors: B N Rao, Sharif RahmanAbstract:This is the first in a series of two papers generated from a study on Probabilistic meshless analysis of cracks. In this paper (Part I), a Galerkin-based meshless method is presented for predicting first-order derivatives of stress-intensity factors with respect to the crack size in a linear-elastic structure containing a single crack. The method involves meshless discretization of cracked structure, domain integral representation of the Fracture integral parameter, and sensitivity analysis in conjunction with a virtual crack extension technique. Unlike existing finite-element methods, the proposed method does not require any second-order variation of the stiffness matrix to predict first-order sensitivities, and is, consequently, simpler than existing methods. The method developed herein can also be extended to obtain higher-order derivatives if desired. Several numerical examples related to mode-I and mixed-mode problems are presented to illustrate the proposed method. The results show that first-order derivatives of stress-intensity factors using the proposed method agree very well with reference solutions obtained from either analytical (mode I) or finite-difference (mixed mode) methods for the structural and crack geometries considered in this study. For mixed-mode problems, the maximum difference between the results of proposed method and finite-difference method is less than 7 . Since the rates of stress-intensity factors are calculated analytically, the subsequent Fracture reliability analysis can be performed efficiently and accurately.
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Probabilistic Fracture Mechanics for nonlinear structures
International Journal of Pressure Vessels and Piping, 2001Co-Authors: Sharif Rahman, J S KimAbstract:Abstract A Probabilistic methodology has been developed for Fracture-Mechanics analysis of nonlinear cracked structures. The methodology involves nonlinear finite element analysis using well-known commercial codes; statistical models for uncertainty in material constitutive law, Fracture toughness, and loads; and standard reliability methods for evaluating Probabilistic characteristics of elastic–plastic Fracture parameter. Numerical examples are presented to illustrate the proposed methodology for two- and three-dimensional cracked structures. The results from these examples show that the methodology is capable of predicting accurate deterministic and Probabilistic characteristics of the J -integral for use in elastic–plastic Fracture Mechanics (EPFM).
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Probabilistic Fracture Mechanics j estimation and finite element methods
Engineering Fracture Mechanics, 2001Co-Authors: Sharif RahmanAbstract:Abstract The objective of this study was to evaluate the adequacy of current J-estimation models commonly used in Probabilistic elastic–plastic analysis of ductile cracked structures. A newly developed Probabilistic model based on elastic–plastic finite element method was used to evaluate the J-estimation model. In both models, the analyses involve elastic–plastic Fracture Mechanics for underlying deterministic calculations, statistical representation of uncertainties in loads, crack size, and material properties involving both tensile and Fracture toughness characteristics, and standard computational methods of structural reliability theory. Numerical examples are presented for two- and three-dimensional cracked structures. The results show that the Probabilistic analysis based on J-estimation model provides accurate estimates of failure probability when compared with those predicted by generally more accurate finite element model. The uncertainty in the crack size, if exists, can have a significant effect on the probability of failure, particularly when the crack size has a large coefficient of variation. A finite element-based Probabilistic Fracture-Mechanics model is useful in benchmarking approximate results of J-estimation analysis.