bluuebunny/crossref_metadata_2025_split huggingface dataset:
Specimen Size and Geometry Effects on the Master Curve Fracture Toughness Measurements of EUROFER97 and F82H Steels
Authors: Chen Xiang (Frank) , Sokolov Mikhail A. , Gonzalez De Vicente Sehila M. , Katoh Yutai 
Published: November 2022

Abstract
EUROFER97 and F82H are two leading reduced-activation ferritic-martensitic (RAFM) steels for fusion blanket applications. Exposure to the harsh environment of fusion reactors can result in severe degradation of materials fracture toughness (FT). Thus, the post-irradiation evaluation of FT is critical to understanding the material behavior. Due to the space constraint of irradiation facilities, the development of small specimen test techniques (SSTT) is necessary to evaluate the performance of irradiated materials. In this study, we evaluated the specimen size and geometry effects on the ductile-to-brittle transition FT of EUROFER97 batch-3 and F82H-BA12 steels. The specimen thicknesses ranged from 1.65 to 12.7 mm and the geometries included 1.65 mm bend bar, 4 mm mini-compact tension (miniCT), and 0.5T compact tension (CT) specimens. Fracture toughness testing and evaluations were performed using the Master Curve method in the ASTM E1921-19 standard. After size correction to 1T size using the Master Curve method, no specimen size effect was observed between the 4 mm miniCT and 0.5T CT specimens for the Master Curve reference temperature T0Q, while the bend bars yielded a higher T0Q. A strong effect of fatigue precrack front straightness on T0Q for 0.5T CT specimens was observed. The minimum number of specimens needed for each specimen geometry has been determined.
Dancing Manhole-Cover Basics
Authors: van de Meulenhof Niels F. , Tijsseling Arris S. , Vasconcelos Jose G. 
Published: November 2022

Abstract
A manhole is a shaft that functions as an access point to the underground infrastructure and is covered with a very heavy lid, sometimes weighing more than 100 kg. Occasionally a strange phenomenon occurs in which such a manhole cover is lifted above its opening and sort of dances on or above its supporting ring without any human intervention. This usually happens when it is stormy with heavy rainfall, but it is not tied to one specific location. Videos from all over the world can be found on the internet showing such ‘dancing manhole covers’. Sometimes air seems to be the main driving force behind the behavior, sometimes water, and sometimes both. Although the videos are funny, the behavior can create a very dangerous situation for both traffic and pedestrians. In this report the cause of these ‘dancing manhole covers’ is studied.
The ‘dancing’ is simplified into two different problems: one with an overflow of air and one with an overflow of water. For both problems a simple model consisting of differential equations is proposed and the numerical results are studied. The problem with an overflow of air is driven by an influx of air into the manhole from below, resulting in an increase in pressure, which lifts up the cover, until air is allowed to escape, and the pressure decreases again. Two different approaches for the escaping discharge of air are tried. The overflow of water is driven by a constant pressure that is exerted on a water column inside the manhole. Furthermore, a solution to the dancing problem is proposed: attaching the manhole cover to the ground with a hinge. This solution is tested by using a similar model as the one used for the overflow of air.
Research on the Laws of Soil Subsidence Range on the Response of Buried Pipelines
Authors: Xu Feng , Xu Yongsheng , Song Jianfei , Liu Cenfan , Liu Xin 
Published: November 2022

Abstract
In recent years, there have been frequent leakage and explosion accidents caused by the cracking of the circumferential weld of buried pipelines, and soil subsidence is one of the main reasons for the accidents. This paper carries out a numerical simulation analysis based on the soil spring model of the buried pipeline, and studies the mechanical response laws such as axial stress and deformation of buried pipelines under different subsidence ranges. The results show that: With the increases of the subsidence range, the deformation of the pipeline first gradually increases, and then remains unchanged, the axial stress of the pipeline, first increases, then decreases slightly, and finally remains unchanged. With the increase of soil subsidence amount, the dangerous subsidence range of soil increases. When the subsidence amount reaches the yield displacement of the soil, with the increase of subsidence range, the maximum axial stress of the pipeline increases. The results have certain guiding significance for the design and maintenance of buried pipelines.
Research on the Influence of Girth Weld Joint Matching Degree on the Safety Performance of High Steel Grade Pipeline Based on ASME Local Strain Limit Criterion
Authors: Liu Xin , Sun Liang , Xu Yongsheng , Wang Haitao , Deng Guide 
Published: November 2022

Abstract
In this study, numerical simulation is used to analyze the influence of the mechanical properties matching degree of weld, HAZ and base metal on the maximum axial strain of high steel grade pipeline. Based on ASME VIII-2 local strain limit criterion and cumulative damage model, the fracture process of girth weld structure under axial displacement and internal pressure is simulated with XFEM. The material parameters of base metal and weld which are necessary for the simulation calculation are obtained by monotonic tensile test, and the material parameters of HAZ are assumed to be lower than those of the weld and base metal to a certain extent. The results show that for different matching degree combinations, the crack initiation location always appears in the HAZ with the lowest mechanical properties, and the axial strain of the pipeline decreases with the increase of the internal pressure. For the undermatched girth weld, the lower the mechanical properties of the weld is, the smaller the maximum axial strain of the girth weld pipe is. For overmatched girth weld, when the internal pressure is less than 6 MPa, the maximum axial strain of 20% overmatched girth weld pipe is higher than that of 10% overmatched girth weld pipe. However, when the internal pressure is higher than 6 MPa, the maximum axial strain of 20% overmatched girth weld pipe is smaller.
3D Simulation of Propagation Induced by Primary Water Stress Corrosion Cracking for Defect Tolerance Analysis of Dissimilar Metal Welds
Authors: Dulieu Pierre , Lacroix Valéry 
Published: November 2022

Abstract
In the Belgian Pressurized Water Reactors Doel 3-4 and Tihange 2-3, the Reactor Pressure Vessel (RPV) nozzle-to-safe-end Dissimilar Metal butt Welds (DMW) are made of nickel-base alloy 182. This material is known to be susceptible to Primary Water Stress Corrosion Cracking (PWSCC) if the stress level is high enough. As a part of the prevention strategy, weld residual stresses have been assessed from experiments and numerical simulations. Moreover, a Defect Tolerance Analysis (DTA) is conducted to assess the acceptability of flaws that could possibly be detected during In-Service Inspection campaigns and to define reasonable inspection intervals. This analysis accounts for the plant specific residual stress profiles and operating loads to calculate the time for a postulated flaw to grow up to an acceptable size limit. Most of the time, the flaw propagation rate induced by PWSCC relies on stress intensity factors calculated in simplified geometries such as plates or pipes without accounting for the actual weld geometry. Therefore, 3D XFEM crack growth calculations are conducted considering more realistic hypotheses in order to quantify the level of conservatism of the simplified approach. The present paper focuses on the benefit of using detailed simulations of crack growth.
Combined Effect of Sustained Load and Harsh Environment on E-Glass/Epoxy Composites: Long Term Exposure
Authors: Idrisi Amir Hussain , Ismail Mourad Abdel Hamid 
Published: November 2022

Abstract
In this work, the durability of the E-glass/epoxy was investigated in terms of degradation in tensile properties and microstructure. Specimens were conditioned in seawater under sustained load and without load at 23 °C, 45 °C and 65 °C for the period of 15 months. The tensile strength of the E-glass/epoxy reduced gradually with immersion time. It reduced by 11% from 811 MPa to 721 MPa and by 18.2% from 811 MPa to 663 MPa for samples immersed without load and with 15% sustained load respectively. The respective reduction for 23°C and 45°C was 1.1% and 5.5% for samples without load and 6.2% and 11.3% for samples immersion under 15% sustained load after 15 months of exposure. The failure strain of E-glass/epoxy composite was slightly affected for the samples immersed without load during the period of 15 months but it was more noticeable under 15% sustained load at 65°C when the tensile strain reduced to 1.65% after 15 months of immersion. Furthermore, Scanning Electron Microscopy (SEM) analysis was conducted to evaluate the degradation of fiber matrix interface. Results revealed that moisture, temperature and sustained load have a deteriorative impact on the performance of the composite.
Crack Growth Simulation Using Iterative Crack-Tip Modeling Technique
Authors: Lee Gi-Bum , Jang Youn-Young , Huh Nam-Su , Park Sung-Hoon , Park Noh-Hwan , Park Jun , Park Kyoungsoo 
Published: November 2022

Abstract
Because of the long-term operation of nuclear power plants, the assessment of crack growth in pipelines has become one of the most important issues. Crack growth resistance in operating nuclear power plants is typically evaluated using linear elastic fracture mechanics based on ASME B&PV Section XI. However, the ASME method predicts the results conservatively, for complex shapes and conditions, while the finite element analysis, which is more accurate, consumes a substantial amount of time and cost. In this study, a finite element analysis-based iterative crack growth program was created to evaluate cracks with more accuracy and time efficiency. The verification of the program was carried out in two cases. By comparing the produced program with the test result of the three-point bending of the beam with rivet holes, it was shown that the program simulates crack propagation in the right direction. In addition, by comparing the results of the fatigue crack growth (FCG) test of CCT/SENT specimens, it was shown that the program can be applied to the evaluation of major failure mechanisms in the nuclear power plants such as stress corrosion crack (SCC) growth and FCG.
Probabilistic Control Rod Failure Analysis for a Nominal Molten Salt Reactor
Authors: Cathcart Henry , Finley James , Taylor John , Frost Alexander 
Published: November 2022

Abstract
Advanced Modular Reactors (AMRs) are expected to aid in the transition to net-zero emissions. In some candidate AMR concepts, a molten salt/fuel mixture passes through fuel channels in graphite bricks, while other bricks are reserved for the insertion of control rods. The neutron fluence in the reactor core displaces carbon atoms in the graphite, leading to a non-linear change in brick dimensions. This change in dimensions could, in certain circumstances, prevent the insertion of control rods and lead to reactor control failure. This paper explores how the exposure of graphite to radiation could lead to reactor control failure using both deterministic and probabilistic analyses. The deterministic approach determines the change in brick dimensions in a single channel using finite element analysis. Conversely, the probabilistic analysis uses a response surface surrogate Monte-Carlo analysis to predict the likelihood of reactor control failure for a single or multiple channels. The deterministic assessment indicates that reactor control failure is not likely. However, the probabilistic analysis shows that the epistemic and aleatory uncertainties in the reactor aggregate, leading to imperfect tessellation of the graphite bricks and a higher probability of failure. The probabilistic approach suggests that after 10 years, reactor control failure is likely in the outer core channels where the influence of imperfect tessellation is the strongest.
Use of Mini-CT Specimens for Fracture Toughness Characterization of Irradiated Highly Embrittled Weld
Authors: Sokolov Mikhail A. 
Published: November 2022

Abstract
In the 1990’s, the Heavy Section Steel Irradiation Program at the ORNL performed investigation of the shape of the fracture toughness master curve for reactor pressure vessel steel highly embrittled because of irradiation exposure. A radiation-sensitive reactor pressure vessel (RPV) weld with intentionally enhanced copper content, designated KS-01, has been characterized in terms of static initiation (KJc) and Charpy impact toughness in the unirradiated and irradiated conditions. The objective of this original project was to investigate the ability of highly embrittled material to maintain the shape of the unirradiated transition fracture toughness curve, as well as to examine the ability of the Charpy 41-J shift to predict the fracture toughness shift at such high level of embrittlement. Irradiation of this weld was performed at the University of Michigan Ford Reactor in the new HSSI irradiation-anneal-reirradiation (IAR) facility. Broken specimens from that project have been saved in ORNL storage. To verify applicability of Mini-CT specimens for fracture toughness characterization of RPV materials as part of the DOE Light Water Reactor Sustainability Program, Mini-CT specimens were machined from broken Charpy specimens and tested according to ASTM E1921 standard. As result of this study, the fracture toughness of this weld derived by testing Mini-CT specimens in the unirradiated and irradiated conditions is compared to previously reported fracture toughness derived by large number of conventional specimens.
Experience Measuring Acoustic Induced and Flow Induced Vibration in a Blowdown Type System
Authors: Middleton Chris , Eilers Daniel , Karczub Denis , Swindell Rob , Horder Nick , Izuchi Hisao , Mann J. Adin 
Published: November 2022

Abstract
Tests were performed on a mockup of a typical relief/blowdown system. The system consisted of an NPS6x8 pressure relief valve, an NPS12 tailpipe, and an NPS20 header. Small bore connections were installed in the tailpipe and header. Simple structures representing a valve mass and stiffness were attached to the small bore connections. Various industry standard tee connections between the tailpipe and header and the small-bore connections to the tailpipe and the header were studied. The goal of the testing program was to provide data to quantify the tee connection style, mitigation methods, and provide data for improvements and validation of Acoustic Induced Vibration (AIV) and Flow Induced Vibration (FIV) prediction and assessment methods. This paper describes the challenges with measuring the very high strain and vibration levels and the data processing used to extract meaningful data. The learnings about the shifting of internal acoustic modes, separating the contributions of AIV and FIV, and separating the contributions of pipe bending modes, higher order pipe modes, higher order acoustic modes, and acoustic/structural coincidence are also described. This work is connected to other presentations which focus on using the data to predict AIV and FIV in realistic blowdown systems.
Development of a Phased Array Ultrasonic System for Residual Stress Measurement in Welding and Additive Manufacturing
Authors: Javadi Yashar , Hutchison Alistair , Zimermann Rastislav , Lines David , Sweeney Nina E. , Vasilev Momchil , Mohseni Ehsan , Vithanage Randika K. W. , MacLeod Charles N. , Pierce Gareth , Mehnen Jorn , Gachagan Anthony 
Published: November 2022

Abstract
Residual Stress (RS) in engineering components can lead to unexpected and dangerous structural failures, and thus represent a significant challenge to quality assurance in both welding and metal additive manufacturing (AM) processes. The RS measurement using the ultrasonic method is based on the acoustoelasticity law, which states that the Time-of-Flight (ToF) of an ultrasonic wave is affected by the stress field. Longitudinal Critically Refracted (LCR) waves have the highest sensitivity to the stress in comparison with the other type of ultrasonic waves. However, they are also sensitive to the material texture which negatively affects the accuracy of the RS measurement. In this paper, a Phased Array Ultrasonic Testing (PAUT) system, rather than the single element transducers which are traditionally used in the LCR stress measurement technique, is innovatively used to enhance the accuracy of RS measurement. An experimental setup is developed that uses the PAUT to measure the ToFs in the weld, where the maximum amount of tensile RS is expected, and in the parent material, stress-free part. The ToF variations are then interpreted and analyzed to qualify the RS in the weld. The same measurement process is repeated for the Wire Arc Additive Manufacture (WAAM) components. Based on the results, some variations between different acoustic paths are measured which prove that the effect of the residual stress on the ultrasonic wave is detectable using the PAUT system.
Challenges implementing a carer support intervention within a national
stroke organisation: findings from the process evaluation of the OSCARSS
trial
Authors: Darley Sarah , Knowles Sarah , Woodward-Nutt Kate , Mitchell Claire , Grande Gunn , Ewing Gail , Rhodes Sarah , Bowen Audrey , Patchwood Emma 
Published: November 2022

Objectives
To examine the implementation of an intervention to support informal
caregivers and to help understand findings from the Organising Support
for Carers of Stroke Survivors (OSCARSS) cluster randomised controlled
trial (cRCT).

Design
Longitudinal process evaluation using mixed methods. Normalisation
process theory informed data collection and provided a sensitising
framework for analysis.

Setting
Specialist stroke support services delivered primarily in the homes
of informal carers of stroke survivors.

Participants
OSCARSS cRCT participants including carers, staff, managers and
senior leaders.

Intervention
The Carer Support Needs Assessment Tool for Stroke (CSNAT-Stroke)
intervention is a staff-facilitated, carer-led approach to help
identify, prioritise and address support needs.

Results
We conducted qualitative interviews with: OSCARSS cRCT carer
participants (11 intervention, 10 control), staff (12 intervention, 8
control) and managers and senior leaders (11); and obtained 140
responses to an online staff survey over three separate time points.
Both individual (carer/staff) and organisational factors impacted
implementation of the CSNAT-Stroke intervention and how it was received
by carers. We identified four themes: staff understanding, carer
participation, implementation, and learning and support. Staff valued
the idea of a structured approach to supporting carers, but key elements
of the intervention were not routinely delivered. Carers did not
necessarily identify as ‘carers’, which made it difficult for staff to
engage them in the intervention. Despite organisational enthusiasm for
OSCARSS, staff in the intervention arm perceived support and training
for implementation of CSNAT-Stroke as delivered primarily by the
research team, with few opportunities for shared learning across the
organisation.

Conclusions
We identified challenges across carer, staff and organisation levels
that help explain the OSCARSS cRCT outcome. Ensuring training is
translated into practice and ongoing organisational support would be
required for full implementation of this type of intervention, with
emphasis on the carer-led aspects, including supporting carer
self-identification.

Trial registration number
NCT58414120.
Multicentre, randomised trial of preterm infants receiving caffeine and less invasive surfactant administration compared with caffeine and early continuous positive airway pressure (CaLI trial): study protocol
Authors: Ines Felix , Hutson Shandee , Coughlin Katherine , Hopper Andrew , Banerji Anamika , Uy Cherry , Finer Neil , Rich Wade , Morales Ana , Steen Jane , Katheria Anup C 
Published: November 2022

Introduction

Respiratory distress syndrome (RDS) or surfactant deficiency occurs primarily in premature infants resulting in composite outcomes of death or bronchopulmonary dysplasia. Initial management strategies for preterm infants with RDS includes early initiation of continuous positive airway pressure (CPAP) and titration of fractional inspired oxygen (FiO
2
), and may include the use of less invasive surfactant administration (LISA) to avoid the need for mechanical ventilation. In order to optimise success of non-invasive support, the use of early caffeine therapy may be critical to the success of LISA. The objective of our trial is to evaluate whether infants that receive early caffeine, CPAP and surfactant via the LISA method compared with infants that receive caffeine and CPAP alone, have a decreased need for invasive mechanical ventilation in the first 72 hours of life.

Methods and analysis

CaLI is an unblinded multicentre, randomised controlled, trial of 180 preterm infants (24+0–29+6 weeks corrected GA). Criteria for intubation/treatment failure will follow guidelines for the management of RDS, including: (1) CPAP level of 6–8 cmH20 and FiO
2
>0.40 required to maintain saturations 90%–95% for 2 hours after randomisation; (2) a pH of 7.15 or less or a paCO
2
>65 mm Hg on any (2) blood gases (arterial/capillary/or venous) at least 2 hours after randomisation and in the first 72 hours of life; (3) continued apnoea/bradycardia/desaturation events despite nasal intermittent minute ventilation mode of ventilation. Infants will be randomised by 1 hour of life and caffeine/LISA treatments administered by 2 hour of life. Caffeine will be administered prior to surfactant in the LISA arm and before 2 hours of life in the control arm.

Ethics and dissemination
Chiesi Farmaceutici, S.p.A is the sponsor of CaLI. Ethical approval has been obtained. Results will be submitted for publication in peer reviewed journals.

Trial registration number

www.Clinicaltrials.gov
:
NCT04209946; Pre-results
.