bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Overview of Time Dependent Crack Growth Models Used for ERW Seam Weld Analyses
Authors: Olson Richard , Young Bruce , O’Brian Jennifer 
Published: October 2017

In response to the National Transportation Safety Board (NTSB) Recommendation P-09-1, the Department of Transportation (DOT) Pipeline and Hazardous Material Safety Administration (PHMSA) initiated a comprehensive study to identify actions that could be implemented by pipeline operators to significantly reduce longitudinal seam failures in electric resistance weld (ERW) pipe. As part of the project, Task 4 in Phase II was designed to validate existing failure prediction models and, where gaps exist, refine or develop the models needed to assess and quantify defect severity for cold welds, hook cracks, and selective seam weld corrosion (SSWC) (the primary ERW/Flash Weld seam threats) for failure subject to loadings that develop both during hydrotests and in service. These models would then be used to develop new software to support integrity management of seam welds with enough flexibility to benefit from the experience gained during this project.
The purpose of this paper is to review the time-dependent crack growth model used in the development of the PipeAssess PI™ pipeline integrity management software. The model will be discussed in the context of its underlying theory, validation, and application to a set of test cases. Both the stress-activated creep model and consequential tie to fatigue crack growth models are presented, which describe crack growth under hydrostatic holds and subsequent pressure cycles. Full-scale experiments are used to validate the models.
The reports generated during the course of the project are publically available and are located at the PHMSA website: HTTP://PRIMIS.PHMSA.DOT.GOV/MATRIX/PRJHOME.RDM?PRJ=390.
Benchmarking Probabilistic Code for LBB Analysis for Circumferential Cracks
Authors: Kurth Robert E. , Sallaberry Cédric J. , Young Bruce A. , Scott Paul , Brust Frederick W. , Kurth Elizabeth 
Published: October 2017

NRC Standard Review Plan (SRP) 3.6.3 describes Leak-Before-Break (LBB) assessment procedures that can be used to assess compliance with the 10CFR50 Appendix A, GDC-4 requirement that primary system pressure piping exhibit an extremely low probability of rupture. SRP 3.6.3 does not allow for assessment of piping systems with active degradation mechanisms, such as Primary Water Stress Corrosion Cracking (PWSCC) which is currently occurring in systems that have been granted LBB approvals.
There are several codes available for addressing the requirements of GDC-4. This paper addresses three of these codes: (1) xLPR 2.0; (2) PROLOCA; and (3) PROMETHEUS. Each of these codes is described and applied to a representative plant where active degradation mechanisms have been found. Conclusions about the design, results, and interpretation of the results is then provided. In all cases the probability of failure of the pipe is found to be extremely low when the crack inspections and leak detection systems are modeled.
Bending-Torsional Flutter of a Slender Web in a Cross Flow
Authors: Hiroaki Keiichi , Kawai Nobuhito , Watanabe Masahiro 
Published: October 2017

This paper presents a flutter analysis of a slender web in a cross air flow. In the flutter analysis, a Doublet-point method (DPM) [1] based on an unsteady lifting surface theory is used to calculate the unsteady fluid force acting on the sheet surface. The equation of motion of the web with tension is derived by using the finite element method (FEM). Flutter velocity, frequency and mode are examined through the root locus of the flutter determinant of the system with changing flow velocity of air. In this study, these flutter characteristics derived by flutter analysis are compared with wind-tunnel experiments. The influence of tension of the web on flutter velocity, frequency and mode is clarified.
As tension of the web becomes higher, the flutter velocity and corresponding frequency increase. In any tension, coupled mode flutter of bending and torsional modes occurs. Then, local work done by the fluid force around the upstream end of the web is positive. On the other hand, near the downstream end of the web, the local work is negative.
Impulsively-Generated Pressure Transients and Strains in a Cylindrical Fluid-Filled Tube Terminated by a Converging Section
Authors: Veilleux Jean-Christophe , Shepherd Joseph E. 
Published: October 2017

The syringe in a subcutaneous autoinjector may be subjected to internal pressure transients due to the normal operation of the injection mechanism. These transients are similar to transients in fluid-filled pipelines observed during water hammer events. In this paper, the effect of an air gap in the syringe and a converging section are studied experimentally and numerically in a model system which consists of a fluid-filled metal tube that is impulsively loaded with a projectile to simulate the action of the autoinjector mechanism operation.
The air between the buffer and the water results in a complex interaction between the projectile and the buffer. Also, there are tension waves inside the tube due to the presence of a free surface, and this causes distributed cavitation which, in turn, gives rise to steepening of the pressure waves. The converging section can amplify the pressure waves if the wave front is sharp. Pressures as high as 50 MPa have been measured at the apex of the cone with impact velocities of 5.5 m/s.
The OECD-NEA Programme on Metallic Component Margins Under High Seismic Loads (MECOS): Towards New Criteria
Authors: Sollogoub Pierre 
Published: October 2017

MECOS is a Post-Fukushima OECD/NEA initiative, with the following main objectives:
• To quantify the existing margins in seismic analysis of safety class components and assess the existing design practices within a benchmark activity.
• To make proposals for new design/evaluation criteria of pressurized piping systems, accounting for their actual failure mode under strong input motions.
The first part of MECOS consisted of gathering information on i) current design practices and ii) dynamic seismic tests on piping system carried out around the world that could be suitable for benchmarking. Part 2 is a benchmark exercise on piping system tests, and Part 3 are proposals for new criteria. The purpose of the proposed paper is to introduce the work which is undertaken in Part 3 in order to propose design criteria that address the observed fatigue-ratchetting failure modes as well as plastic instability. It includes revisiting the past test results as well as the interpretations that were carried out and conclusions that were drawn at that time, and reanalyzing them in the light of recent developments. Recent experimental programs carried out in Japan and in India will also be addressed.
Modeling of Hypervelocity Impact Experiments Using Gamma-SPH Technique
Authors: Limido Jérôme , Trabia Mohamed , Roy Shawoon , O’Toole Brendan , Jennings Richard , Mindle Wayne L. , Pena Michael , Daykin Edward , Hixson Robert , Matthes Melissa 
Published: October 2017

A series of experiments were performed to study plastic deformation of metallic plates under hypervelocity impact at the University of Nevada, Las Vegas (UNLV) Center for Materials and Structures using a two-stage light gas gun. In these experiments, cylindrical Lexan projectiles were fired at A36 steel target plates with velocities range of 4.5–6.0 km/s. Experiments were designed to produce a front side impact crater and a permanent bulging deformation on the back surface of the target without inducing complete perforation of the plates. Free surface velocities from the back surface of target plate were measured using the newly developed Multiplexed Photonic Doppler Velocimetry (MPDV) system.
To simulate the experiments, a Lagrangian-based smooth particle hydrodynamics (SPH) is typically used to avoid the problems associated with mesh instability. Despite their intrinsic capability for simulation of violent impacts, particle methods have a few drawbacks that may considerably affect their accuracy and performance including, lack of interpolation completeness, tensile instability, and existence of spurious pressure. Moreover, computational time is also a strong limitation that often necessitates the use of reduced 2D axisymmetric models. To address these shortcomings, IMPETUS Afea Solver® implemented a newly developed SPH formulation that can solve the problems regarding spurious pressures and tensile instability. The algorithm takes full advantage of GPU Technology for parallelization of the computation and opens the door for running large 3D models (20,000,000 particles). The combination of accurate algorithms and drastically reduced computation time now makes it possible to run a high fidelity hypervelocity impact model.
A Comparative Study of Concentrically and Eccentrically Pierced Flat Unstayed Heads
Authors: Chandiramani Dipak K. , Gopalakrishnan Shyam , Mathkar Ameya , Nawandar Suresh K. 
Published: October 2017

Clause UG - 39 of ASME Section VIII Division 1 [1] provide rules for compensation of openings in flat stayed/ flat unstayed heads having fitted nozzles.
The rules provided in Clause UG - 39 and its sub clauses apply to all openings other than small openings covered by UG - 36 (c)(3)(a) and provide rules for compensation of openings to those geometries which confirms to the geometric limitations specified therein.
The rules provided in Clause UG - 39 of ASME Section VIII Division 1 are based on area replacement method. This method is also elaborated in WRC Bulletin 335 Aug 1988[4]. The conclusion of this bulletin is applicable to ASME Section VIII Div 1, ASME Section I, ASME B 31.1 and ASME Section III Class 2 and 3. This method requires that the metal cut out by an opening be replaced by reinforcement within a prescribed zone around the opening. This methodology is relatively simple and vast majority of the piping and pressure vessels with openings conforming to this methodology have given satisfactory service.
In Code [1], as such there appears to be no restriction on the location of the nozzle opening, i.e., a header flat head pierced concentrically or eccentrically to locate the nozzle opening as long as the required area is obtained and the stresses are within allowable limits. While both these alternatives would be acceptable in Code [1] constructions, the actual stresses at the header flat heads/nozzle junction may vary considerably.
The work reported in this paper was undertaken to make a comparative study on the effect of unstayed flat head pierced concentrically or eccentrically by using ASME Section VIII Division 1 and to study the stress pattern in both the cases using Finite Element Analysis (FEA) as a referral methodology.
Ultrasonic Testing and Photographic Imaging System for Tube to Tubesheet Weld of Heat Exchanger
Authors: Abe Masamitsu , Murakami Joichi , Shinmura Naoto 
Published: October 2017

This paper describes non-destructive testing systems that were constructed to inspect tube-to-tubesheet welds of a heat exchanger operating in a chemical plant such as urea products.
A phased array ultrasonic testing system inserts a testing device into the tube, rotates it and scans the tube-to-tubesheet welds, thereby detecting any weld defects that are not only parallel to a tube axis but also in any direction, and displaying the size and location of the defects on a computer screen using system software. These welds have conventionally been inspected by liquid penetrant testing and visual testing as surface inspections during fabrication at shop and periodic inspection at plant site. This new method, however, provides a practical way to the inspection of weld inside.
In addition, in a photographic imaging system, an imaging device is placed on the tube end to take photos of the inner surface of tube and the outer surface of tube including the tube-to-tubesheet weld. These photos are analyzed any suspected damage area, then displaying the location of the area on a computer screen using system software. In the periodic inspections at site, the presence or absence of a local corrosion dent or other damage are determined by visual testing and finger touch, but it is concerned that hundreds of welds will not be covered by these methods sufficiently. Consequently, this new method enables us to eliminate lacks of inspection and the secular change of each weld will be easily grasped with the suitable records.
The above testing systems perform in a short amount of time and are highly reliable methods with inspection records. For this reason, in particular, the application of the new method to a periodic inspection at site is expected to reduce the period until the plant resumes operations, and also to remove any concerns about emergency shutdown of an operating plant due to damages in the tube-to-tubesheet welds.
Relative Influence of Soil Stiffness and Elbow Geometry on Buried Piping Thermal Stresses
Authors: Marohl Michael P. H. , Frazee Glenn R. , Musto Thomas M. 
Published: October 2017

The design of buried piping systems requires special considerations. Historically, buried piping was evaluated for thermal expansion and contraction using simple hand calculations considering the piping to be fully-constrained by the surrounding soil. With the development of analytical software, more advanced analysis of buried piping is possible considering detailed piping routing and the stiffness of the surrounding soil and of the piping itself (in cases of more flexible piping materials). Typically, the areas of highest thermal stress occur at changes in direction (i.e. elbows, etc.) due to the applied moments, and the relative stress magnitude is influenced by the stiffness of the surrounding soil.
Due to the relatively high coefficient of thermal expansion of polyethylene, stresses in buried piping due to thermal expansion and contraction are of particular note for high density polyethylene (HDPE) piping. This paper examines the relative influence of the analytical representations of a variety of HDPE piping elbow geometries (e.g. mitered elbows, molded elbows, etc.) and corresponding soil restraint. The study demonstrates that total longitudinal stress calculated in a finite element analysis may be reduced using minor to moderate efforts of refinement.
Research and Development of Viscous Fluid Dampers for Improvement of Seismic Resistance of Thermal Power Plants: Part 1 — Fundamental Analysis and Component Test
Authors: Tanaka Go , Minagawa Keisuke , Aida Kiyoshi , Fujita Satoshi 
Published: October 2017

In 2011, Great East Japan Earthquake that is the largest earthquake ever observed occurred. The earthquake had large energy, huge tsunami, long duration time and many aftershocks. Devastated area needed retrieval and revival. However, when electric power was lost, the retrieval delayed. It is necessary to improve seismic proof construction for power plants.
In this paper, authors proposed vibration control by adding dampers for coal-fired power plant and developed it. Fundamental analysis and component test of the damper were conducted.
As the analytical results, characteristic of the damper was searched what kind of performance is more effective for the coal-fired power plants. In the component test, actual scaled prototype of the developed damper was produced and its performance was checked by loading test. As the test results, suitable characteristic of the damper was searched by the analysis. Finally, authors proposed two analytical methods of the developed damper.
A Study on the Influence of Sea Water Convective Heat Transfer Coefficient in Design Verification of Subsea HPHT Equipment
Authors: Sepehri Ali , Harbert Stuart , Holberry Dave 
Published: October 2017

As HPHT activity continues to grow and well conditions become more severe, more advanced analysis methods are required. Thermal/heat transfer and structural Finite Element Analyses (FEA) play a fundamental role in the design of subsea equipment for HPHT application.
The objective of this study is to evaluate the effect of seawater convective heat transfer coefficient on design verification of a subsea drilling connector in the HPHT environment (bore pressure more than 15,000 psi, and/or bore temperature more than 300°F). The design verification work contains the elastic-plastic assessments including protection against plastic collapse (global), local failure, hydrotest and ratcheting criteria. The fatigue study is also performed per ASME Boiler & Pressure Vessel Code, Section VIII, Div. 3, Article KD-4 in compliance with API 17TR8. The effect of seawater convective heat transfer coefficient on the global, ratcheting and fatigue criteria is studied/presented. Results show that the higher value of heat transfer coefficient (convection) results in more thermal gradients through assembly causing higher stress and plastic strain deformation in the connector components and lower fatigue life.
Effects of Partial Cooling on Tightness of Heat Exchanger Girth Flange
Authors: Takahashi Kyohei , Miyashita Toshikazu , Kataoka Shunji , Uno Yoshiaki , Sato Takuya 
Published: October 2017

For the girth flange of heat exchangers, the circumferential temperature distribution of shell and connecting flange due to inside fluid will affect tightness of the girth flange, however this effect is not considered in present design codes. It is important to know the key characteristics of flange tightness to minimize the risk of leakage. In past studies, the effects of circumferential temperature distribution on flange tightness were investigated at high temperature operations. The effects of partial cooling on flange tightness might be severer than circumferential high temperature distribution.
In this paper, the effects of partial cooling on flange tightness were studied. The flange tightness was evaluated by wideness of partially cooled region (liquid level) of heat exchanger and gasket recovery characteristics parametrically. Based on these studies, it was concluded that the gasket contact pressure was decreased by the partial cooling of heat exchanger and the effects of the above mentioned factors were summarized quantitatively.
Further Validation of the Weighted Stress Intensity Factor Rate (WKR) Method for Stainless Steel Pressurised Water Reactor Fatigue Crack Growth Calculations
Authors: Emslie Julian , Cruchley Sam , Currie Chris , Wright Keith 
Published: October 2017

The reference Fatigue Crack Growth (FCG) rate behaviour for austenitic stainless steel in a deaerated Pressurised Water Reactor (PWR) environment is provided in ASME Boiler and Pressure Vessel Code Section XI Code Case N-809. This FCG law is dependent on temperature, R ratio and environment; the environment effect is defined through a load rise time parameter. The basis for the law is contained within a large dataset of testing of simple waveforms carried out by various industry sources.
In a previous paper, PVP2016-63497, it was demonstrated that the use of load rise time as defined in Code Case N-809 did not provide a good characterisation of FCG rate for complex waveforms where the loading rate varies during the fatigue cycle. For waveforms representative of a thermal shock, the method in Code Case N-809 leads to overly conservative predictions of FCG rate. An improved method was postulated: the Weighted Stress Intensity Factor Rate (WKR) method. This method expresses the FCG law in terms of loading rate; a weighting is then applied to the effect of the loading rate based on its position within the fatigue cycle, according to the exponent on load. This method can be used to provide an effective rise time, which may be used in place of the rise time definition given in Code Case N-809. The WKR method was shown to give excellent correlation with test results for a number of complex waveforms.
This paper provides additional data and discussion related to the WKR method. This includes additional simple waveforms with two different loading rates (2-stage waveforms), several additional waveforms which are representative of PWR plant thermal shock loading and 2-stage waveforms at higher R ratios. Final confirmatory tests are also reported which were carried out at different temperatures and using different grades of stainless steel. These data address the gaps identified in PVP2016-63497. Having analysed the total evidence for the WKR method, the authors consider that there is a sufficiently strong basis for the method to be incorporated into calculations using Code Case N-809.
In order to assist in application of the WKR method, a simple worked example is also provided in this paper.
Development on Rubber Bearings for Sodium-Cooled Fast Reactor: Part 5 — Non-Linear Analytical Models for Thick Rubber Bearing
Authors: Hirotani Tsutomu , Mori Takahiro , Fukasawa Tsuyoshi , Okamura Shigeki , Yamamoto Tomohiko , Watakabe Tomoyoshi 
Published: October 2017

Application of seismic isolation system is essential to reduce the seismic force not only for the horizontal direction but also for vertical direction since the component installed to the Sodium-Cooled-Fast-Reactor (SFR) has thin-walled structures to reduce thermal stress. The authors have performed static loading tests using a half-scale thick rubber bearing to investigate ultimate properties include breaking, and confirmed that the thick rubber bearings have sufficient performance compared to the conventional thin rubber bearings.
The present paper describes the evaluation of analytical models for the thick rubber bearing by following two approaches based on the obtained test results.
a) Spring model
Horizontal and vertical spring models, which are employed to the non-linear seismic response analysis, are compiled to examine applicability of conventional analytical model for thin rubber bearing. In addition, the horizontal and vertical spring models are modified, as a suitable non-linear analytical model for the thick rubber bearing. For the horizontal direction, hysteresis rules composed of multiple lines considering slip effect are modified to correspond to the hysteresis characteristics obtained test results. Hysteresis rules under vertical direction composed of multiple lines in consideration of effect on the shear strain due to horizontal seismic response is constructed.
b) 3D FEM model
The prediction methods of break strain for thin rubber bearings as the conventional rubber bearing have been examined, which have been proposed by the authors as 3D finite element analysis in consideration of the hyper elasticity. To improve suitable the above mentioned methods for the corresponding the restoring force characteristics for thick rubber bearing, 3D FEM model containing a higher-order elements was constructed to express the skeleton curve as restoring force characteristics up to the breaking points. The validity of the constructed 3D FEM model was investigated comparing breaking test results under horizontal and vertical direction. Consequently, the analytical results demonstrated that the skeleton curves up to the horizontal and vertical breaking points can express with constructed 3D FEM model. In addition, this paper describes the criteria with respect to the breaking strain by utilizing the analytical results.