scholarly journals EVALUATION ON MECHANICAL FRACTURE OF PWR PRESSURE VESSEL AND MODELING BASED ON NEURAL NETWORK

2016 ◽  
Vol 18 (2) ◽  
pp. 87 ◽  
Author(s):  
Mike Susmikanti ◽  
Roziq Himawan ◽  
Abdul Hafid ◽  
Entin Hartini
Keyword(s):  
Neural Network ◽  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Pressure Vessel ◽  
Fracture Analysis ◽  
J Integral ◽  
Network Approach ◽  
Neural Network Approach ◽  
Mechanical Fracture

ABSTRACT EVALUATION ON MECHANICAL FRACTURE OF PWR PRESSURE VESSEL AND MODELING BASED ON NEURAL NETWORK. The important component of the PWR is a pressure vessel. The material resistance in the pressure vessel needs to be evaluated. One way of evaluation is by the mechanical fracture analysis. The modeling needs to know the phenomena of the analysis result in general. A number of researches have been completed on the calculation of mechanical fracture in the pressure vessel with an internal load. The mechanical fracture was modeled using a neural network approach. In relation to the material resistance of the pressure vessel, which is used in PWR AP1000, the material must be evaluated because of the effect of the load. The modeling is needed to predict the effect of the load. The aim of this study is to evaluate the material resistance through mechanical fracture analysis because of the influence load on the pressure vessel on PWR AP1000. The material, which was observed, is SA 508. This analysis consists of the calculation of stress intensity factor and J-integral with some load at the crack propagation position. The fracture mechanic was analyzed by finite element simulation. The result of Stress Intensity factor and J-Integral was compared with fracture toughness to know the durability of the material. The modeling of  J-Integral and Stress Intensity Factor were obtained for some load based on neural network approach. Keywords: Material resistance, mechanical fracture, neural network, PWR, pressure vessel, crack propagation.   ABSTRAK EVALUASI FRAKTUR MEKANIK PADA BEJANA TEKAN PWR DAN PEMODELAN BERBASIS NEURAL NETWORK. Komponen penting dari PWR adalah  bejana tekan. Ketahanan bahan di bejana tekan perlu dievaluasi. Salah satu cara adalah dengan analisis fraktur mekanik. Pemodelan diperlukan untuk mengetahui fenomena hasil analisis pada umumnya. Terdapat penelitian untuk perhitungan fraktur mekanik dalam bejana tekan dengan beban internal. Penelitian lain adalah hasil dari fraktur mekanik dimodelkan menggunakan pendekatan jaringan syaraf. Sehubungan dengan ketahanan material dari bejana tekan yang digunakan dalam PWR AP1000, bahan harus dievaluasi karena efek dari beban. Pemodelan diperlukan untuk memprediksi pengaruh beban pada bahan dalam bejana tekan. Tujuan dari penelitian ini adalah untuk mengevaluasi ketahanan material melalui analisis fraktur mekanik karena pengaruh beban pada bejana tekan. Bahan yang diamati, adalah SA 508. Analisis ini terdiri dari perhitungan faktor intensitas tegangan dan J-integral dengan beberapa beban pada posisi perambatan retak. Fraktur mekanik dianalisis dengan metode elemen hingga. Hasil faktor intensitas tegangan dan J-Integral dibandingkan dengan ketangguhan patah untuk mengetahui daya tahan material. Pemodelan J-Integral dan faktor intensitas stres diperoleh untuk beberapa beban berdasarkan  jaringan saraf. Kata kunci: Ketahanan bahan, teknik patahan,  jaringan syaraf,  PWR,  bejana tekan, perambatan retak. 

scholarly journals THE ANALYSIS OF OPTIMAL CRACK RATIO FOR PWR PRESSURE VESSEL CLADDING USING GENETIC ALGORITHM

2018 ◽  
Vol 20 (1) ◽  
pp. 47 ◽  
Author(s):  
Mike Susmikanti ◽  
Roziq Himawan ◽  
Jos Budi Sulistyo
Keyword(s):  
Genetic Algorithm ◽  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Fracture Mechanics ◽  
Intensity Factor ◽  
Pressure Vessel ◽  
J Integral ◽  
Mechanical Fracture ◽  
Optimal Value ◽  
Materials Used

Several aspects of material failure have been investigated, especially for materials used in Reactor Pressure Vessel (RPV) cladding. One aspect that needs to be analyzed is the crack ratio. The crack ratio is a parameter that compares the depth of the gap to its width. The optimal value of the crack ratio reflects the material's resistance to the fracture. Fracture resistance of the material to fracture mechanics is indicated by the value of Stress Intensity Factor (SIF). This value can be obtained from a J-integral calculation that expresses the energy release rate. The detection of the crack ratio is conducted through the calculation of J-integral value. The Genetic Algorithm (GA) is one way to determine the optimal value for a problem. The purpose of this study is to analyze the possibility of fracture caused by crack. It was conducted by optimizing the crack ratio of AISI 308L and AISI 309L stainless steels using GA. Those materials are used for RPV cladding. The minimum crack ratio and J-Integral values were obtained for AISI 308L and AISI 309L. The SIF value was derived from the J-Integral calculation. The SIF value was then compared with the fracture toughness of those material. With the optimal crack ratio, it can be predicted that the material boundaries are protected from damaged events. It can be a reference material for the durability of a mechanical fracture event.Keywords: Fracture mechanics, RPV cladding, J-Integral, Stress Intensity Factor, Genetic Algorithm ANALISIS RASIO RETAK OPTIMAL UNTUK KELONGSONG BEJANA TEKAN PWR MENGGUNAKAN ALGORITMA GENETIKA. Banyak aspek kegagalan material telah diteliti, terutama untuk bahan yang digunakan pada kelongsong bejana tekan reaktor (RPV). Salah satu aspek yang perlu dianalisis adalah rasio retak. Rasio retak adalah parameter yang membandingkan kedalaman celah dengan lebarnya. Nilai optimal rasio retak mencerminkan ketahanan material terhadap patahan. Ketahanan material terhadap mekanika patahan ditunjukkan oleh nilai Stress Intensity Factor (SIF). Nilai ini dapat diperoleh dari perhitungan J-integral yang mengekspresikan tingkat pelepasan energi. Deteksi rasio retak dilakukan melalui perhitungan nilai J-integral. Algoritma Genetika (GA) adalah salah satu cara untuk menentukan nilai optimal suatu masalah. Tujuan dari penelitian ini adalah untuk menganalisis kemungkinan patah yang disebabkan oleh retak dengan menganalisis rasio retak baja tahan karat AISI 308L dan AISI 309L dengan GA. Bahan tersebut digunakan untuk kelongsong RPV. Rasio retak optimal dan nilai J-Integral diperoleh untuk AISI 308L dan AISI 309L. Nilai SIF berasal dari perhitungan J-Integral. Nilai SIF kemudian dibandingkan dengan ketangguhan retak material tersebut. Dengan rasio retak optimal, dapat diprediksi batas rasio retak sehingga terlindung dari kejadian patah. Hal ini dapat menjadi bahan referensi untuk ketahanan dari mekanika patahan.Kata kunci: Mekanika Patahan, Kelongsong Bejana Tekan Reaktor, J-Integral, Faktor Intensitas Tegangan, Algoritma Genetik

scholarly journals Analisis Probabilistic Fracture Mechanics Pada Evaluasi Keandalan Bejana Tekan Reaktor Secara 3-D

2018 ◽  
Vol 24 (1) ◽  
Author(s):  
Entin Hartini ◽  
Roziq Himawan ◽  
Mike Susmikanti
Keyword(s):  
Fracture Toughness ◽  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Probability Density Function ◽  
Fracture Mechanics ◽  
Intensity Factor ◽  
Pressure Vessel ◽  
J Integral ◽  
Probabilistic Fracture Mechanics ◽  
Reactor Pressure

Analisis integritas material sangat diperlukan pada Reactor Pressure Vessel (RPV). Komponen tersebut merupakan pressure boundary yang berfungsi untuk mengungkung material radioaktif. Adanya retak pada dinding dapat mempengaruhi integritas RPV tersebut. Penelitian ini bertujuan melakukan analisis fracture mechanics menggunakan model probabilistik untuk evaluasi keandalan RPV. Model probabilistik digunakan untuk pendekatan karakter random dari kuantitas input seperti sifat mekanik material dan lingkungan fisik. Karakter random dari kuantitas input menggunakan teknik sampling berdasarkan probability density function.  Material yang digunakan pada RPV adalah baja feritik (SA 533). Analisis fracture mechanics dilakukan berdasarkan metode elemen hingga (FEM) menggunakan perangkat lunak MSC MARC. Output dari MSC MARC adalah nilai J integral untuk mendapatkan nilai stress intensity factor (SIF) pada evaluasi keandalan bejana tekan reaktor 3D. Hasil perhitungan menunjukan bahwa SIF probabilistik lebih dulu mencapai nilai batas fracture toughness  dibanding  SIF deterministik. Nilai SIF yang dihasilkan dengan metode probabilistik adalah 95,8  MPa m0,5, sedangkan dengan metode deterministik adalah 91,8 MPa m0,5, rasio crack (a/c) semakin kecil akan dihasilkan nilai SIF yang semakin besar.Kata kunci: Probabilistic fracture mechanics, bejana tekan, 3-D.

Structural Integrity of Penetration Nozzle of Reactor Pressure Vessel Head of PWR Plant

2008 ◽  
Author(s):  
Kiminobu Hojo ◽  
Naoki Ogawa ◽  
Yoichi Iwamoto ◽  
Kazutoshi Ohoto ◽  
Seiji Asada ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Stress Field ◽  
Pressure Vessel ◽  
Structural Integrity ◽  
Complex Structure ◽  
Reactor Pressure Vessel ◽  
Reactor Pressure

A reactor pressure vessel (RPV) head of PWR has penetration holes for the CRDM nozzles, which are connected with the vessel head by J-shaped welds. It is well-known that there is high residual stress field in vicinity of the J-shaped weld and this has potentiality of PWSCC degradation. For assuring stress integrity of welding part of the penetration nozzle of the RPV, it is necessary to evaluate precise residual stress and stress intensity factor based on the stress field. To calculate stress intensity factor K, the most acceptable procedure is numerical analysis, but the penetration nozzle is very complex structure and such a direct procedure takes a lot of time. This paper describes applicability of simplified K calculation method from handbooks by comparing with K values from finite element analysis, especially mentioning crack modeling. According to the verified K values in this paper, fatigue crack extension analysis and brittle fracture evaluation by operation load were performed for initial crack due to PWSCC and finally structural integrity of the penetration nozzle of RPV head was confirmed.

Finite Element Fracture Mechanics Study of Pre-Northridge Connections

2006 ◽  
Vol 324-325 ◽  
pp. 1007-1010 ◽  
Author(s):  
Hong Bo Liu ◽  
Chang Hai Zhai ◽  
Yong Song Shao ◽  
Li Li Xie
Keyword(s):  
Stress Intensity Factor ◽  
Finite Element ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Fracture Behavior ◽  
Integral Approach ◽  
J Integral ◽  
Finite Element Analyses ◽  
Element Analysis ◽  
Weld Root

The objective was to quantify the variation of stress intensity factor to weld root flaw sizes in steel frame connections. Finite-element analyses were used to study fracture toughness in welded beam-column connections. Investigations of fracture behavior mainly focused on the standard pre-Northridge connection geometry. Finite element analysis was performed using the ANSYS computer program. Stress intensity factor was calculated through a J-integral approach. Results show that stress intensity factor is not uniform and is largest in the middle of beam flange. Stress intensity factor increases nearly linear with the increase of flaw size. Backing bars have little effect on weld fractures.

Formulation for Stress Intensity Factors and J-Integral Calculation by Eddy Current Testing

2015 ◽  
Vol 660 ◽  
pp. 225-230 ◽  
Author(s):  
Salaheddine Harzallah ◽  
Mohamed Chabaat ◽  
Sekoura Benissad
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Eddy Current ◽  
Eddy Currents ◽  
J Integral ◽  
Intensity Factors ◽  
Magnetic Vector ◽  
Current Testing ◽  
Set Up

In this paper, we present a method for computing the Stress Intensity Factor (SIF) and J-Integral, by measuring and testing related Eddy currents. In the process, we provide a magnetic vector based formulations for the theoretical set up. Furthermore, we provide relevant applications having theory consistent results.

3-D Elastic Analysis of a Circular Nozzle Corner Crack

1986 ◽  
Vol 108 (4) ◽  
pp. 474-478 ◽  
Author(s):  
W. W. Wilkening
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Crack Front ◽  
Pressure Vessel ◽  
Circular Crack ◽  
Elastic Analysis ◽  
Corner Crack ◽  
Linear Elastic ◽  
Circular Nozzle

A 3-D linear elastic analysis has been performed for a circular crack located in the nozzle corner region of a nuclear pressure vessel. The stress intensity factor, K, was found to be virtually constant along the crack front for this particular nozzle corner flaw, which extends one quarter of the distance through the nozzle corner diagonal. The magnitude of K is discussed in relation to the stress intensity factor for the ASME Maximum Postulated Flaw, and is compared to the results of a number of other analyses reported in the literature.

Research on Stress Intensity Factor of Gear Crack and its Variation with Changes of Gear Parameters

2011 ◽  
Vol 121-126 ◽  
pp. 2211-2217
Author(s):  
Fei Fei Dong ◽  
Ren Ping Shao ◽  
Jie Ma
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Fracture Analysis ◽  
Tooth Root ◽  
Dimensional Model ◽  
Linear Fracture ◽  
Tooth Gear ◽  
Single Tooth ◽  
Gear Crack

Used the theory of linear fracture mechanics and FEM, the two-dimensional model of single-tooth gear is established under the environment of ANSYS. The stress intensity factor(SIF) is analyzed when gear crack occurs and the variation of SIFs is discussed with changes of crack length, gear module, number of teeth, load when gear crack emerges at the pitch circle and tooth root respectively, and the influence of different cracked directions on tooth root is studied; The pragmatic expression of SIFs KI, KII have been brought forth with the results obtained by FEM. These establishes a good foundation on the fracture analysis and diagnosis of gear

Sign in / Sign up

Export Citation Format

Share Document