bluuebunny/crossref_metadata_2025_split huggingface dataset:
STYLE Project: Assessment of Transferability of Fracture Material Properties From Specimens to Large Components by Local Approach to Fracture
Authors: Le Delliou Patrick , Moinereau Dominique , Keim Elisabeth , Nicak Tomas 
Published: November 2014

Within the framework of the FP7 European project STYLE, a large scale experiment was performed at EDF R&D on a cladded ferritic pipe (Mock-Up 3). The objective of this experiment was to investigate the transferability of material properties from small specimens to large scale components.
The large scale experiment involved applying 4-point bending under displacement control at room temperature to a clad ferritic steel pipe with an inner surface crack. The goal of the experiment was to initiate ductile crack growth and track the resulting stable crack growth until the surface flaw breaks through the wall.
The pipe was representative of a surge line, consisting of a clad ferritic pipe with an outer diameter of 424 mm, and base metal wall thickness of 31 mm, with an austenitic stainless steel cladding layer 5 mm thick on the inner surface. The base metal is a low alloy 20 MnMoNi 5 5 steel (corresponding to the specifications of an SA 508 Grade 3, Class 1 steel).
The pipe test was conducted in 2012 in the EDF R&D 4-point bending frame. Following the experiment, various specimens were taken from the mock-up to identify the material behavior and provide data to investigate the transferability of the material fracture properties.
This paper recalls briefly the large scale experiment results and presents the main experimental results from the specimens. Then the results of the local approach finite element computations with the Rousselier model are presented and compared with the experimental results.
The Use of FFS Methodology for Determining the Residual Life of a High Pressure Autoclave Reactor
Authors: Keltjens Jan 
Published: November 2014

Autoclave reactors at SABIC Geleen were typically inspected at a four year interval. The inspection consisted of UT and eddy current inspection of the bore and cross-bores of the reactor. The possibilities of extending this interval were assessed using FFS methodologies from API 579-1/ASME FFS1 [1] in addition to the ASME VIII Division 3 [2] rules. ASME VIII Division 3 is primarily a design code, although Appendix B from the 2013 edition includes guidance on extension of inspection frequency. This work was performed in 2010 when this appendix was not included in the code.
This paper describes the study, the results and indicates further opportunities of FFS methodology in high pressure equipment.
Effects of Uncertainties in Boundary Conditions on Dynamic Characteristics of Industrial Plant Components
Authors: Bursi Oreste S. , Abbiati Giuseppe , Caracoglia Luca , Reza Md Shahin 
Published: November 2014

Seismic risk assessment of industrial plants is of paramount importance to ensure adequate design against earthquake hazards. Seismic vulnerability of industrial plant components is often evaluated through a fragility analysis to conform to structural safety requirements. Fragility curves of single components are usually developed by neglecting the effect of actual boundary conditions. Thus, an incorrect evaluation of individual fragility curves can affect the overall fragility curve of a system. This may lead to “erroneous” seismic risk evaluation for a plant in comparison with its real state. Hence, it is important to study the effect of uncertainties, introduced at the boundaries when coupling effects are neglected, on the dynamic characteristics of a system.
Along this line, this paper investigates the effects of uncertain boundary conditions on the probability distributions of the dynamic properties of a simple chain-like system with increasing number of degrees of freedom. In order to describe the uncertain boundary condition, a modified version of the well-known β distribution is proposed. Subsequently, the Analytical Moment Expansion (AME) method is employed to estimate the statistical moments of the output random variables as an alternative to more computationally-demanding Monte Carlo simulations. Finally, a preliminary extension of the proposed approach to a realistic piping system connected to a class of broad/slender tanks is discussed.
Numerical Approach for Containment Assessment of Transport Packages Under Regulatory Thermal Test Conditions
Authors: Sterthaus Jens , Ballheimer Viktor , Bletzer Claus , Linnemann Konrad , Nehrig Marko , Wille Frank 
Published: November 2014

The requirements of the IAEA safety standards for Type B(U) packages include the thermal test as part of test sequences that represents accident conditions of transport. In comparison to mechanical tests, e.g., 9 m drop onto an unyielding target with short impact durations in a range of approximately 10 ms to 30 ms, the extended period of 30 min is defined in regulations for exposure of a package to a fire environment. Obviously, the required containment capability of the package has to be ensured not only after completing the test sequence but also over the course of the fire test scenario.
Especially, deformations in the sealing area induced by the non-uniform thermal dilation of the package can affect the capability of the containment system. Consequently, thermo-mechanical analyses are required for the assessment.
In this paper some aspects of finite element analysis (FEA) of transport packages with bolted closure systems under thermal loading are discussed. A generic FE model of a cask is applied to investigate the stress histories in the bolts, lid, and cask body as well as the deformations in the sealing area and the compression conditions of the gasket. Based on the parameter variations carried out, some recommendations in regard to modeling technique and results interpretation for such kind of analyses are finally given.
Alternative Characterization Rules for Quasi-Laminar Flaws
Authors: Lacroix Valéry , Dulieu Pierre , Couplet Damien 
Published: November 2014

During the 2012 outage at Doel 3 and Tihange 2 Nuclear Power Plants, a large number of quasi-laminar indications were detected, mainly in the lower and upper core shells. As a consequence, both units remained core unloaded pending the elaboration of an extensive Safety Case demonstrating the Structural Integrity of the RPVs in all operating modes, transients and accident conditions.
A large part of this demonstration consists of the Flaw Acceptability Assessment inspired by the ASME XI procedure but adapted to the nature and number of indications found in the Doel 3 and Tihange 2 RPVs. In particular, ASME XI IWB-3300 article requires combining closely spaced flaws in order to account for their mechanical interactions. However, it appeared early that the strict application of the current ASME XI proximity criteria for laminar flaws to the actual flaw indications found at Doel 3 led to unrealistic results and conclusions. Therefore, an alternative methodology to derive suitable characterization rules applicable to specific flaws observed at Doel 3 and Tihange 2 RPVs has been successfully developed, implemented and validated.
Intentional Destructive Testing: A Means for Establishing Mechanical Integrity in Plants, Facilities, and Pipelines
Authors: Alexander Chris , Vyvial Brent 
Published: November 2014

Operators of plants, facilities, and pipelines have at their disposal multiple resources for evaluating the integrity of identified features and anomalies. With advances in inspection technology, industry is being called upon to evaluate an ever-increasing number of features. When a feature is identified as a threat and severe enough to warrant repair or replacement, operators are faced with sometimes significant costs.
In this paper the authors provide guidance on the benefits associated with full-scale testing for evaluating mechanical integrity, referred to Intentional Destructive Testing (IDT). Unlike many analysis techniques that require the development and implementation of assumed operating and boundary conditions, well-designed IDT programs are able to replicate in situ conditions to provide operators with a clear understanding regarding the behavior of anomalies and their response to simulated operating conditions. Case studies are included to demonstrate the merits of the IDT approach. In using IDT, operators have improved confidence in predicting the behavior of identified features to ensure that maintenance resources are properly allocated for either continuing operation or repairing anomalies.
Composite Repair Performance at Elevated Temperatures
Authors: Alexander Chris , Souza Jim , Whalen Casey 
Published: November 2014

For the better part of the past 20 years composite materials have been used to repair damaged piping and pressurized components in plants, refineries, and pipelines. The use of composite materials has been accompanied by comprehensive research programs focused on the development and assessment of using composite technology for restoring integrity to damaged piping and pressurized components. Of particular interest are composite repair standards such as ISO 24817 and ASME PCC-2 that provide technical guidance in how to properly design composite repair systems.
The vast body of research completed to date has involved assessments at ambient conditions; however, at the present time there is significant interest in evaluating the performance of composite repair materials at elevated temperatures. This paper is focused on the topic of high temperature composite repairs and addresses the critical role of utilizing temperature-based mechanical properties to establish a composite repair design. The backbone of this effort is the development of composite performance curves that correlate change in strength as a function of temperature. A discussion on supporting full-scale pressure test results are included, along with guidance for users in how to properly design composite repair systems for applications at elevated temperatures.
Design Rules for Ratcheting Damage in AFCEN RCC-MRX 2012 Code
Authors: Lamagnère P. , Lejeail Y. , Petesch C. , Lebarbé T. , Matheron P. , Taheri S. , Martin A. 
Published: November 2014

The paper describes the design rules for ratcheting in the 2012 edition of the RCC-MRx Code issued in French and English versions by AFCEN (French Association for the rules governing the Design, Construction and Operating Supervision of the Equipment Items for Electro Nuclear Boilers).
For austenitic stainless steels, the RCC-MRx Code uses the efficiency diagram concept to evaluate an effective primary stress, Peff. Peff is defined as a virtual stress that applied alone would cause the same strain as the combination of the primary static stress and the secondary cyclic strain really applied. This concept is extended to significant creep domain and includes corrections to take into account structures cases presenting secondary membrane stresses (e.g. cylinders subjected to axial thermal gradients varying with time and space) or short duration overloads (as a level A seismic load, or an overload due to rapid drain-out caused by a sodium-water reaction).
An alternative 3Sm design rule is proposed for all materials in the case of non-significant creep damage.
Difficulties in Predicting Cycles of Failure Using Finite Element Analysis of Acoustically Induced Vibration (AIV) Problems in Piping Systems
Authors: Ghosh Arindam , Niu Yaying , Arjunan Rajesh 
Published: November 2014

While finite element modeling analysis is becoming more frequent for analyzing AIV problems, in the absence of experimental data in large diameter pipe, there is no industry wide accepted methodology for representing the pressure excitation for the pipe so accurate cycles to failure may be predicted. The assumptions involved in determining the actual amplitude of the acoustic excitation, which modes may develop and how they couple with the structure all contribute to the overall uncertainty of the problem.
Depending on the degree of correlation assumed between the structural and acoustical mode shapes the results vary dramatically. There are also variations based on the number of participating modes assumed. Relative strengths of a Weldolet®, an Insert Weldolet® that is a variation of Sweepolet® and a Reducing Tee connection were analyzed for a 24×6 inch Sch. 10S and STD connection assuming various degrees of correlation and mode participation. Wide fluctuations in the cycles to failure were observed based on the assumptions; however, the stress ratios between the connections are relatively stable. This suggests the use of an acoustic Stress Intensification Factor (SIF) in conjunction with Fatigue Strength Reduction Factors (FSRF) to determine suitability of connections in AIV service rather than an absolute value of cycles to failure.
Further investigation of the trends in the value of SIF as the D/d (branch to header diameter) and D/t (diameter to thickness) ratios over a range of pipe diameter are required before these SIF’s could be put into use. Experimental data for a few controlled failure cases are required to ground the finite element prediction in reality. As the experiment is more likely to be conducted with air the possible pitfalls in extending the results from air to commonly used process fluid are also discussed.
Development of Design Rules for Three-Segment Pipe Clamp Connectors
Authors: Bankston David O. , Kuo Hsin 
Published: November 2014

The design rules for clamped connections in the ASME Boiler and Pressure Vessel Code (Section VIII, Div. I, Appendix 24) were developed for two-segment clamp connectors and must be modified to accommodate alternative clamp configurations.
Developing a simplified rule-based model for predicting three-segment pipe clamp connectors (3-PCC)connector pressure capacities will greatly simplify the evaluation of 3-PCC connectors.
The first goal of this paper is to develop a general parametric design rule set for multiple-clamp-segment pipe by expanding upon the published requirements of the ASME Boiler and Pressure Vessel Code for two-segment pipe clamp connectors and pipe flanges using basic principles. The next goal is to apply the design rule set to a typical 3-PCC design and to summarize the rules.
The results of this paper provide a parametric rule-based approach to evaluating the pressure capacity of a 3-PCC.
This paper has been developed in partial fulfillment of the requirements for the Master’s Degree Program at Washington State University.
This work is performed in support of the US Department of Energy, under contract to Bechtel National Inc., # DE-AC27-01RV14136.
Large-Eddy Simulation of Cross-Flow Induced Vibrations of a Single Flexible Tube in a Normal Square Tube Array
Authors: Berland Julien , Deri Enrico , Adobes André 
Published: November 2014

The cross-flow induced vibrations in water of a single flexible tube in a normal square array of rigid tubes are investigated by means of large-eddy simulations, based on the classical Smagorinsky model. The flow configuration and the operating conditions are taken from the experiments of Granger et al. (J. Fluid Struct., 1993). A fully-coupled fluid-structure calculation is hence performed: the tube dynamics is modeled by a mass-spring-damper system, and the motion of the fluid domain is accounted for by a moving mesh technique.
The numerical results are compared to the experimental data in terms of amplitude and frequency of the flexible tube oscillations, for various inflow velocities. In addition, characteristics of the flow-induced forces are discussed: features of the power spectral densities of lift and drag forces, such as the envelope spectrum or the spanwise correlation length are investigated.
Numerical Estimation of Flow Penetrating Depth Into Stagnant Branch Pipes for Thermal Fatigue Prediction
Authors: Ishikawa Yoshihiro , Okuda Yukihiko , Kasahara Naoto 
Published: November 2014

In the nuclear power plants, there are many branch pipes with closed-end which are attached vertically to the main pipe. We consider a situation in which the high temperature water is transported in the main pipe, the branch pipe is filled with stagnant water which has lower temperature than the main flow, and the end of the branch pipe is closed. At the branch connection part, it is known that a cavity flow is induced by the shear force of the boundary layer which separates from the leading edge of the branch pipe along the main pipe wall. In cases where the high temperature water penetrates into the branch pipe, there is a possibility that a steep and large temperature gradient field, called “thermal stratification layer” is formed at the boundary between high and low temperature water in the branch pipe. If the thermal stratification layer is formed in a bend pipe, which is used for connecting the vertical branch pipe and to a horizontal pipe, at the same time, the temperature fluctuation by the thermal stratification layer motion occurs, there may cause the thermal stress in the piping material. Furthermore, keeping the piping material under the thermal stress, there might be a possibility of a crack on the surface of the bend pipe. For this reason, the evaluation of the position where the thermal stratification layer reaches is very important during early piping design process. And, deeply understanding regarding the phenomena, is also important. However, because of the complexities of the phenomena, it is difficult to immediately clarify the whole mechanisms of the thermal stress arising due to the temperature fluctuation by the thermal stratification layer change. The complete prediction method for the position of the thermal stratification layer based on the mechanisms that is able to be applied to any piping system, any temperature and any velocity conditions, is also difficult. Therefore, a practical approach is required.
The authors attempt to develop the practical estimation method for the thermal stratification layer position using the three-dimensional Navier-Stokes simulation which was based on the Reynolds-average in order to reduce the computational costs. In this paper, three different configurations of the piping were simulated and the simulation results were compared with the experimental results obtained by the other research group.
STYLE: Modelling of the Extraction of Bend Specimens From Repair Weld and the Influence of Residual Stress on Fracture Testing
Authors: James Peter , Ford Mike 
Published: November 2014

Within the EU 7th framework programme, STYLE, a number of large-scale tests have been performed. One of these tests, Mock-Up 2 (MU-2), was performed on a through wall crack located at a repair weld adjacent to a multi-pass narrow-gap weld. The aim of MU-2 was to investigate ductile crack growth under conditions with significant levels of residual stress. As part of the materials testing programme, low-constraint fracture specimens (three-point bend specimens with a/t=0.1) were extracted from the weld to test the weld materials fracture toughness. An overview of these tests is provided here.
However, these low constraint tests demonstrated somewhat unusual fatigue crack growth on inserting the crack, leading to the crack depth being shorter in the centre of the specimens to the outside. Subsequently, although it has not been possible to use these specimens to determine the materials J-R curve, it does provide a features test for ductile modelling with the Gurson-Tvergaard-Needleman (GTN) local approach model for ductile crack growth. This paper provides an overview of the modelling associated to understand these observations, including an estimate of the retained residual stress, fatigue growth estimates and subsequent ductile modelling.
An overview of the calibration of the GTN model is also provided using the weld material’s tensile tests, high constraint compact-tension tests and MU-2.
Braiding: A New Production Method Approach for Composite Pressure Vessels in Automotive Applications
Authors: Lengersdorf Michael , Multhoff Jörg , Gries Thomas 
Published: November 2014

With the first serial production of a hydrogen fuel cell car announced to enter the market in 2015, there is a prospective mass market for mobile pressure vessel applications. In automotive applications three factors are mainly decisive for a successful integration: low weight, a competitive price range and a safe operation implementation. Composite vessels can fulfill these demands. State-of-the art for the production of the composite structure is wet-filament winding. It is well established for smaller production volumes. However the potential of rise in output is limited. In filament winding only a limited number of usually 1–10 fibres is layed onto a mandrel at once. Braiding in comparison allows the simultaneously deposition of a multitude of fibres, standard machinery allow braiding of more than 200 fibres. A filament wound composite structure lacks fracture resistance under certain load cases. Composite structures known to have better fracture resistance are interlaced fibre architectures, such as braid. This applies especially for impact performance [7].
The braiding process strongly depends on the desired product. The machinery has to be chosen accordingly to application regarding e.g. the number of fibre carriers and their quantities. In automotive applications the dimensions are limited to a certain range due to available build space in the car. This paper will show which parameters have to be considered when setting up a production line for braided pressure vessels. This is done against the background of typical pressure vessel dimensions in automotive applications.
Performance-Based NDE Personnel Qualifications
Authors: Stephens Henry M. 
Published: November 2014

This paper establishes an alternative approach for nondestructive examination (NDE) personnel qualification for the boiler and pressure vessel (B&PV) industry. This is the “white paper” developed by the Section XI, Division 2, Task Team, Performance-based NDE Personnel Qualifications. It is anticipated to be the basis for the NDE personnel qualification criteria for the revised Section XI, Division 2, REQUIREMENTS FOR RELIABILITY AND INTEGRITY MANAGEMENT (RIM) PROGRAM FOR NUCLEAR POWER PLANTS that is currently being developed.
Based on review of a number of quantitative NDE reliability studies conducted to-date the current deterministic approach to NDE personnel qualification based on such schemes as ASNT SNT-TC-1A, ANSI/ASNT CP-189, EN-473, ISO-9712 and other similar approaches are not as effective as desired. The goal of this document is to present an alternative approach to the deterministic NDE personnel qualification schemes.
This paper presents a systematic approach to training together with performance-based tests, psychometrically validated evaluation of knowledge and skills that will improve a NDE candidate’s performance. A majority of traditional employer-based written examinations are not developed or validated psychometrically. The use of third-party psychometrically validated examinations would replace the current practice of employer developed and administered examinations. It improves upon traditional ASNT SNT-TC-1A, ASNT/ANSI CP-189, ISO-9712, etc., requirements by including more comprehensive hands-on practical examinations on a statistically valid set of samples containing flaws representative of those expected to be encounter in shop and field conditions. The sample sets will be designed for either a “general” NDE method, or “limited” technique(s) of a method, or for industry specific sector needs, as applicable.