scholarly journals Finite element analysis of high-density polyethylene pipe in pipe gallery of nuclear power plants

2020 ◽  
Author(s):  
Jianfeng Shi ◽  
Anqi Hu ◽  
Fa Yu ◽  
Ying Cui ◽  
Ruobing Yang ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Density Polyethylene ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
High Density ◽  
Element Analysis ◽  
Polyethylene Pipe

Finite Element Reliability Analysis of Steel Containment Vessels with Corrosion Damage

2015 ◽  
Vol 10 (3) ◽  
pp. 527-534 ◽  
Author(s):  
Xiaolei Wang ◽  
◽  
Dagang Lu ◽  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Reliability Analysis ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Corrosion Damage ◽  
Element Analysis ◽  
Containment Vessel ◽  
Reliability Method

Containment vessels, which contain any radioactive materials that would be released from the primary system in an accident, are the last barrier between the environment and the nuclear steam supply system in nuclear power plants. Assessing the probability of failure for the containment building is essential to level 2 PSA studies of nuclear power plants. Degradation of containment vessels of some nuclear power plants has been observed in many countries, so it is important to study how the corrosion has adverse effects on the capacity of containment vessels. Conventionally, the reliability analysis of containment vessels can be conducted by using Monte Carlo Simulation (MCS) or Latin Hypercube Sampling (LHS) with the deterministic finite element analysis. In this paper, a 3D finite element model of an AP1000 steel containment vessel is constructed using the general-purpose nonlinear finite element analysis program ABAQUS. Then the finite element reliability method (FERM) based on the first order reliability method (FORM) is applied to analyze the reliability of the steel containment vessel, which is implemented by combining ABAQUS and MATLAB software platforms. The reliability and sensitivity indices of steel containment vessels under internal pressure with and without corrosion damage are obtained and compared. It is found that the FERM-based procedure is very efficient to analyze reliability and sensitivity of nuclear power plant structures.

Coalescence Criterion of Part-Through Wall Cracks in Steam Generator Tubes of Nuclear Power Plants

2004 ◽  
Author(s):  
Jeries Abou-Hanna ◽  
Timothy McGreevy ◽  
Saurin Majumdar ◽  
Amit J. Trivedi ◽  
Ashraf Al-Hayek
Keyword(s):  
Finite Element ◽  
Steam Generator ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Local Instability ◽  
Element Analysis ◽  
Failure Pressure ◽  
Ligament Failure ◽  
Steam Generator Tubes

In scheduling inspection and repair of nuclear power plants, it is important to predict failure pressure of cracked steam generator tubes. Nondestructive evaluation (NDE) of cracks often reveals two neighboring cracks. If two neighboring part-through cracks interact, the tube pressure, under which the ligament between the two cracks fails, could be much different than the critical burst pressure of an individual equivalent part-through crack. The ability to accurately predict the ligament failure pressure, called “coalescence pressure,” is important. The coalescence criterion, established earlier for 100% through cracks using nonlinear finite element analyses [1–3], was extended to two part-through-wall axial collinear and offset cracks cases. The ligament failure is caused by local instability of the radial and axial ligaments. As a result of this local instability, the thickness of both radial and axial ligaments decreases abruptly at a certain tube pressure. Good correlation of finite element analysis with experiments (at Argonne National Laboratory’s Energy Technology Division) was obtained. Correlation revealed that nonlinear FEM analyses are capable of predicting the coalescence pressure accurately for part-through-wall cracks. This failure criterion and FEA work have been extended to axial cracks of varying ligament width, crack length, and cases where cracks are offset by axial or circumferential ligaments. The study revealed that rupture of the radial ligament occurs at a pressure equal to the coalescence pressure in the case of axial ligament with collinear cracks. However, rupture pressure of the radial ligament is different from coalescence pressure in the case of circumferential ligament, and it depends on the length of the ligament relative to crack dimension.

Finite element analysis of single-edgecracked rolled high-density polyethylene

Polymer ◽  
1994 ◽  
Vol 35 (7) ◽  
pp. 1442-1451 ◽  
Author(s):  
Min-Diaw Wang ◽  
Eiji Nakanishi ◽  
Sadao Hibi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Density Polyethylene ◽  
High Density ◽  
Element Analysis

Evaluation of Ultrasonic Phased-Array for Detection of Planar Flaws in High-Density Polyethylene (HDPE) Butt-Fusion Joints

2016 ◽  
Author(s):  
Matthew S. Prowant ◽  
Kayte M. Denslow ◽  
Traci L. Moran ◽  
Richard E. Jacob ◽  
Trenton S. Hartman ◽  
...  
Keyword(s):  
High Density Polyethylene ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Phased Array ◽  
National Laboratory ◽  
Cooling Water ◽  
Pacific Northwest National Laboratory ◽  
Nuclear Regulatory Commission ◽  
High Density

The desire to use high-density polyethylene (HDPE) piping in buried Class 3 service and cooling water systems in nuclear power plants is primarily motivated by the material’s high resistance to corrosion relative to that of steel alloys. The rules for construction of Class 3 HDPE pressure piping systems were originally published as an alternative to the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME BPVC) in ASME Code Case N-755 and were recently incorporated into the ASME BPVC Section III as Mandatory Appendix XXVI (2015 Edition). The requirements for HDPE examination are guided by criteria developed for metal pipe and are based on industry-led HDPE research and conservative calculations. Before HDPE piping will be generically approved for use in U.S. nuclear power plants, the U.S. Nuclear Regulatory Commission (NRC) must have independent verification of industry-led research used to develop ASME BPVC rules for HDPE piping. With regard to examination, the reliability of volumetric inspection techniques in detecting fusion joint fabrication flaws against Code requirements needs to be confirmed. As such, confirmatory research was performed at the Pacific Northwest National Laboratory (PNNL) from 2012 to 2015 to assess the ability of phased-array ultrasonic testing (PAUT) as a nondestructive evaluation (NDE) technique to detect planar flaws, represented by implanted stainless steel discs, within HDPE thermal butt-fusion joints. All HDPE material used in this study was commercially dedicated, 305 mm (12.0 in.) nominal diameter, dimension ratio (DR) 11, PE4710 pipe manufactured with Code-conforming resins, and fused by a qualified and experienced operator. Thermal butt-fusion joints were fabricated in accordance with or intentionally outside the standard fusing procedure specified in ASME BPVC. The implanted disc diameters ranged from 0.8–2.2 mm (0.03–0.09 in.) and the post-fabrication positions of the discs within the fusion joints were verified using normal- and angled-incidence X-ray radiography. Ultrasonic volumetric examinations were performed with the weld beads intact and the PA-UT probes operating in the standard transmit-receive longitudinal (TRL) configuration. The effects of probe aperture on the ability to detect the discs were evaluated using 128-, 64-, and 32-element PA-UT probe configurations. Results of the examinations for each of the three apertures used in this study will be discussed and compared based on disc detection using standard amplitude-based signal analysis that would typically be used with the ultrasonic volumetric examination methods found in ASME BPVC.

Finite Element Analysis of Plastic Strain Distribution in Multipass ECAE Process of High Density Polyethylene

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
B. Aour ◽  
F. Zaïri ◽  
M. Naït-Abdelaziz ◽  
J. M. Gloaguen ◽  
J. M. Lefebvre
Keyword(s):  
Finite Element Analysis ◽  
Plastic Deformation ◽  
Finite Element ◽  
Plastic Strain ◽  
High Density Polyethylene ◽  
Strain Distribution ◽  
High Density ◽  
Element Analysis ◽  
Die Geometry ◽  
Plastic Strain Distribution

Equal channel angular extrusion (ECAE) is a relatively novel forming process to modify microstructure via severe plastic deformation without modification of the sample cross section. In this study, an optimized design of die geometry is presented, which improves homogeneity of the plastic deformation and decreases the pressing force required for extrusion. Then, a typical semicrystalline polymer (high density polyethylene) was subjected to multipass ECAE using two different processing routes: route A where the sample orientation is kept constant between passes and route C where the sample is rotated by 180 deg. Compression tests at room temperature and under different strain rates were used to identify the material parameters of a phenomenological elastic-viscoplastic model. Two-dimensional finite element analysis of ECAE process was carried out, thus allowing to check out the homogeneity of the plastic strain distribution. The effects of die geometry, number of passes, processing route, and friction coefficient on the plastic strain distribution were studied. The simulations were performed for three channel angles (i.e., 90 deg, 120 deg, and 135 deg), considering different corner angles. According to simulation results, recommendations on the angular extrusion of the polymer are provided for improving die and process performance.

Linear viscoelastic modelling of profiled high density polyethylene pipe

1996 ◽  
Vol 23 (2) ◽  
pp. 395-407 ◽  
Author(s):  
Ian D. Moore ◽  
Fuping Hu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Density Polyethylene ◽  
Parallel Plate ◽  
High Density ◽  
Time Dependent ◽  
Element Analysis ◽  
Vertical Diameter ◽  
Polyethylene Pipes ◽  
Linear Viscoelastic

Rheological model parameters for a linear viscoelastic finite element analysis are developed for corrugated polyethylene pipes. Relaxation test data from parallel plate load tests on lined corrugated high density polyethylene pipes are used, for pipes deflected to 5% and 10% vertical diameter decrease. Three-dimensional time-dependent finite element analysis is then used to estimate the time-dependent response of a 610 mm diameter pipe subjected to a constant rate of vertical diameter decrease with time. Predictions are obtained for deflection rates varying over three orders of magnitude, for direct comparison with laboratory test results. Small deflection (5%) relaxation rheology leads to good predictions of measured response up to 3% vertical pipe deflection. Large deflection (10%) rheology yields reasonable predictions for pipe response between 3% and 10% vertical deflection. Levels of strain are examined in the pipe profile, and a peak local tensile strain of 0.6% is estimated for the pipe deflected to 3% vertical diameter decrease. The rheological models should permit prediction of response under parallel plate loading for other pipe profiles. These models might also be used for estimation of pipe response under other loading conditions (such as deep burial in the field).

Development of an Automatic 3D Finite Element Crack Propagation System

2014 ◽  
Author(s):  
Hiroaki Doi ◽  
Hitoshi Nakamura ◽  
Wenwei Gu ◽  
Hiroshi Okada
Keyword(s):  
Finite Element ◽  
Crack Propagation ◽  
Integral Method ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Element Analysis ◽  
3D Finite Element ◽  
Asme Code ◽  
Virtual Crack Extension Method

When cracks are detected in piping in nuclear power plants during in-service inspections, the crack propagation is usually calculated using approximation formulas of stress intensity factor (SIF) provided in the ASME Code, the JSME Rules or the literature. However, when the crack is detected in complicated-shaped locations in components, finite element analysis (FEA) needs to be used to calculate the SIFs. Accordingly, a method of automatically conducting FEA for crack propagations in nuclear power plants is needed. Therefore, we, the Nuclear Regulation Authority (NRA, Japan) have developed an automatic 3D finite element crack propagation system (CRACK-FEM) for nuclear components. The developed CRACK-FEM uses three methods of SIF calculation: the Virtual Crack Extension Method (VCEM), the Virtual Crack Closure-Integral Method (VCCM) and the Domain Integral Method (DIM). Each method uses different meshes, so users can select a method which uses a suitable mesh for the problem. The software includes a geometry generator to create complicated weld models, and a mesh generator which can deal with interior boundaries formed between different materials. The functions and accuracy of the new software are demonstrated by solving several sample problems involving crack propagation. The contents of this paper were conducted as a research project of the Japan Nuclear Energy Safety Organization (JNES) when one of the authors (Doi) belongs to JNES. After this project, JNES was abolished and its staff and task were absorbed into NRA on March 1, 2014.

Development of Stress Intensity Factors for Deep Surface Cracks in Plates and Cylinders

2012 ◽  
Author(s):  
Yinsheng Li ◽  
Hiroto Itoh ◽  
Kunio Hasegawa ◽  
Kazuya Osakabe ◽  
Hiroshi Okada
Keyword(s):  
Finite Element Analysis ◽  
Stress Intensity Factor ◽  
Finite Element ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Nuclear Power ◽  
Power Plants ◽  
Structural Integrity ◽  
Surface Cracks ◽  
Element Analysis

A number of deep surface cracks have been detected in components of nuclear power plants in recent years. The depths of these cracks are even greater than the half of crack lengths. When a crack is detected during in-service inspections, methods provided in the ASME Boiler and Pressure Vessel Code Section XI or JSME Rules on Fitness-for-Service for Nuclear Power Plants can be used to assess the structural integrity of cracked components. The solution of the stress intensity factor is very important in the assessment of structural integrity. However, in the current codes, the solutions of the stress intensity factor are provided for semi-elliptical surface cracks with a limitation of a/l ≤ 0.5, where a is the crack depth, and l is the crack length. In this study, in order to assess the structural integrity in a more rational manner, the solutions of the stress intensity factor were calculated using finite element analysis with quadratic hexahedron elements for deep semi-elliptical surface cracks in plates, and for axial and circumferential semi-elliptical surface cracks in cylinders. The crack dimensions were focused on the range of a/l = 0.5 to 4.0. Solutions were provided at both the deepest and the surface points of the cracks. Furthermore, some of solutions were compared with the available existing studies and with solutions obtained using finite element analysis with quadratic tetrahedral elements and the virtual crack closure-integral method. As the conclusion, it is concluded that the solutions proposed in this paper are applicable in engineering applications.

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