bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Bolt Strength Characteristics in Bolted Joints Using an Optical Fiber Sensor System
Authors: Shirakawa Atsushi , Sawa Toshiyuki 
Published: November 2019

Abstract
Bolted joints are used in many industrial products such as mechanical structures, automobiles, airplanes, chemical plants, and so on. In many cases, after the design of new products is finished, various tests on the bolt and bolted joints are carried out using actual parts to prevent accidents due to bolt loosening and fracture. At the same time, in the strength tests, external force measurement, axial bolt force measurement and so on are included. However, there are no advanced tests in which axial bolt strain distribution or bolt elongation in actual parts and so on are measured. Therefore, in this research, a new method for evaluating bolt strength characteristics using an optical fiber sensor system capable of measuring actual parts is demonstrated. First, a tensile strength test using an optical fiber sensor is carried out to measure strain distribution in a bolt, and a maximum strain value position in the measured clamp load-strain curve is shown. Then, the elongation at each part of the bolt is shown. Next, yield clamp bolt force is found using this sensor system in torque/clamp force testing. In addition, the measured yield clamp bolt force is compared with the values in the conventional measurement method and in the estimation formula. Also, discussed is the effective cross section area by which the stress at the engaged threads is calculated under tensile load. Finally, another case where an optical fiber sensor system is used for bolt fastening evaluation is discussed.
A Co-Reliability-Target-Based Fatigue Failure Probability Model for Implementing the New ASME Boiler and Pressure Vessel Section XI Division 2 Reliability and Integrity Management Code: A Technical Brief
Authors: Fong Jeffrey T. , Heckert N. A. , Filliben J. J. , Freiman Stephen W. 
Published: November 2019

Abstract
ASME Pressure Vessel and Piping Code (BPVC) Section XI Committee Division 2 has recently completed the development of a proposed new code named the “Reliability and Integrity Management (RIM).” RIM was developed using the system-based code (SBC) concept proposed by the Japanese Society of Mechanical Engineers (JSME) in 2012. Key to the SBC concept is the requirement for the establishment of a co-reliability target (or, reliability-index target by JSME terminology). Such target is usually in the low probability ranges such as 1.0 E−8 to 1.0 E−3. In a paper presented at the 2018 International Symposium on Structural Integrity (ISSI2018), Nov. 2–5, 2018, Nanjing, China, we developed a new theory of fatigue and creep rupture life modeling for metal alloys at room and elevated temperatures such that the co-reliability target can be estimated from fatigue and creep tupture test data. To illustrate an application of this new modeling approach, we included two numerical examples using (a) the fatigue failure data of six AISI 4340 steel specimens at room temperature (Dowling, N. E., 1973) and (b) the creep rupture time data of 37 specimens of 1.3Mn-0.5Mo-0.5Ni steel plates at 500 C (NRIM, 1987). Since the ASME BPVC Section XI Div. 2 RIM Code has just been developed, and the information in that yet-to-be-published ISSI2018 Proceedings is critical to the implementation of that RIM Code, it is, therefore, of interest to the engineering community to have a preview of that information in the form of a technical brief as described in this PVP2019 conference paper.
Research and Development of Viscous Fluid Dampers for Improvement of Seismic Resistance of Thermal Power Plants: Part 7 — Evaluation of Lifetime Using Experimental Design Method
Authors: Aida Kiyoshi , Minagawa Keisuke , Tanaka Go , Fujita Satoshi 
Published: November 2019

Abstract
In 2011, Great East Japan Earthquake that was the largest earthquake in Japanese history occurred. The earthquake had large acceleration, long duration and a lot of aftershocks, and coal-fired thermal power plants were damaged by the earthquake. Boiler structures in coal-fired thermal power plants are generally high-rise structures, and boilers are simply suspended from the top of the support structures in order not to restrict thermal expansion. Therefore boilers are easy to vibrate. In order to suppress vibration of boilers during earthquakes, stoppers are generally set between boilers and support structures. The stoppers are made of steel, and dissipate vibration energy by plastic deformation. However aseismic requirements for thermal power plants have been increased as a result of the Great East Japan Earthquake. Thus authors have developed a vibration control damper for coal-fired power plants. The damper is set instead of conventional stopper. Construction of the damper is similar to oil dampers, but inner fluid is viscous fluid. In PVP 2017, the basic performance of the proposed damper was presented. In PVP 2018, influence of dispersion of damper properties was also investigated. In addition, seismic response analyses using various earthquakes that include long period and long duration earthquake waves were carried out. As a result of previous investigations, it was confirmed that the proposed damper has good performance in its lifetime. However, parameters of dampers were selected manually. Therefore, influence of parameters of dampers on the lifetime were evaluated theoretically by using the experimental design method in this paper. The experimental design method is one of the effective techniques for research such as investigation of the influence of the habitat environment on the growth of crops. The selection of damper parameters is complex optimization, because so many variables need to be optimized. Therefore the experimental design method is suitable technique for the evaluation of damper parameters. This paper evaluates lifetime of dampers from the viewpoint of the experimental design method.
Application of the Incremental Step Loading Technique to Small Punch Tests in Hydrogen Embrittlement
Authors: Arroyo B. , González P. , Andrea L. , Álvarez J. A. , Lacalle R. 
Published: November 2019

Abstract
In this work, the incremental step loading technique to measure hydrogen embrittlement threshold in steels from ASTM F1624 standard is applied to the Small Punch test technique. For the experimental program, a medium strength steel is employed, simulating the hydrogen embrittlement environment by a cathodic polarization of 5 mA/cm2 in an acid electrolyte mainly consisting of 1N H2SO4 in H2O. Regular standard tests on cylindrical tensile specimens were carried out under the same environment following the ASTM F1624 standard, observing the same trends in both cases, which validates the methodology proposed.
In order to adapt the aforementioned standard to small punch testing, the duration of the loading steps had to be modified, proposing much shorter ones according to the Small Punch specimen dimensions and the punch rate taking place in these scenarios, which is pointed in bibliography. This proposal allows to obtain a threshold load by using at least 3 specimens in a total time of around a week.
Simple Calculations of J-Integral for Through-Wall Crack in Welded Pipes Based on Failure Assessment Diagram
Authors: Park Jun-Geun , Jeon Da-Som , Huh Nam-Su , Lee Sang-Min , Kim Ye-Ji 
Published: November 2019

Abstract
In the present study, simple J-integral estimations of welded pipes with a circumferential through-wall crack (TWC) in weld zone were proposed based on the failure assessment diagram (FAD) concept using scaling factor that is defined as a ratio of plastic limit load of welded pipe to that of base metal pipe. For this purpose, the detailed 3-dimensional (3-D) finite element (FE) limit analyses for welded pipes with a circumferential TWC have been systematically carried out considering various thickness of pipe, circumferential crack lengths, strength mismatches between base and weld metal, widths of weldment and locations of TWC (weld center and interface between the weld metal and the base metal). As for loading conditions, axial tension and global bending were considered in the FE analyses.
Based on the present FE results, numerical expressions on scaling factors representing the ratio of plastic limit loads of welded pipes to those of base metal pipes were derived. Finally, the new FAD-based J-estimations based on option 1 concept was proposed to predict J-integrals of welded pipes incorporating the present scaling factors, i.e. ratio of plastic limit load. Moreover, the proposed J estimations were validated by comparing with FE results using actual properties.
Effect of Plasticity on Creep Deformation in Type 316H Stainless Steel
Authors: Mamun Abdullah Al , Simpson Chris , Erinosho Tomiwa , Agius Dylan , Reinhard Christina , Mostafavi Mahmoud , Knowles David 
Published: November 2019

Abstract
The creep life and deformation behaviour of high-temperature steels can be significantly affected by the prior plastic loading. This effect is partly due to the generation of intergranular strains from the grain-scale elastic and plastic anisotropic deformation during plastic loading. This paper investigates the effect of these plasticity generated intergranular strains on the subsequent creep strain accumulation behavior in type 316H stainless steel. An in-situ synchrotron diffraction experiment was conducted at 550°C, where the sample was loaded incrementally to different magnitudes of plastic strain, followed by a displacement-controlled stress relaxation dwell at each of this stage. The lattice strains of 4 grain families were measured during these stages. It was found that the intergranular strains generated during the plastic deformation significantly affect the relative magnitude of creep strain accumulation in different grain families. A subtle but significant difference has been observed between the creep intergranular strain accumulation behavior and the plastic intergranular strain accumulation behavior in different grain families which can be used to interrogate the validity of any micromechanical models’ formulation for creep and plastic deformation. The macroscopic stress relaxations measured from the experiment were compared with the prediction from a novel crystal plasticity based micromechanical model developed in our group. A good overall match was found between the experiment and the model regarding the magnitude of stress relaxation after various level of plasticity. The experiments have demonstrated that the model requires further development to accurately predict the rate of stress relaxation and the micro scale lattice strain evolution during creep.
Heat Treatment of Fabricated Components and the Effect on Properties of Materials
Authors: Gopalakrishnan Shyam , Mathkar Ameya 
Published: November 2019

Abstract
Most of the heavy thickness boiler and pressure vessel components require heat treatment — in the form of post weld heat treatment (PWHT) and sometimes coupled with local PWHT. It is also a common practice to apply post heating/ intermediate stress relieving/ dehydrogenation heat treatment in case of alloy steels.
The heat treatment applied during the various manufacturing stages of boiler and pressure vessel have varying effects on the type of material that is used in fabrication. It is essential to understand the effect of time and temperature on the properties (like tensile and yield strength/ impact/ hardness, etc.) of the materials that are used for fabrication.
Considering the temperature gradients involved during the welding operation a thorough understanding of the time-temperature effect is essential. Heat treatments are generally done at varying time and temperatures depending on the governing thickness and the type of materials. The structural effects on the materials or the properties of the materials tends to vary based on the heat treatment. All boiler and pressure vessel Code require that the properties of the material should be intact and meet the minimum Code specification requirements after all the heat treatment operations are completed.
ASME Code(s) like Sec I, Section VIII Division 1 and Division 2 and API recommended practices like API 934 calls for simulation heat treatment of test specimen of the material used in fabrication to ascertain whether the intended material used in construction meets the required properties after all heat treatment operations are completed.
The work reported in this paper — “Heat treatment of fabricated components and the effect on properties of materials” is an attempt to review the heat treatment and the effect on the properties of materials that are commonly used in construction of boiler and pressure vessel. For this study, simulation heat treatment for PWHT of test specimen for CS/ LAS plate and forging material was carried out as specified in ASME Section VIII Div 1, Div 2 and API 934-C. The results of heat treatment on material properties are plotted and compared. In conclusion recommendations are made which purchaser/ manufacturer may consider for simulation heat treatment of test specimen.
The Influence of Prior Plastic Loading on the Accumulation of Creep Strain in 316H Stainless Steel
Authors: Taylor Megan , Mamun Abdullah al , Knowles David 
Published: November 2019

Abstract
Structural components are regularly exposed to cyclic thermal stresses which can induce plastic deformation within them. The accumulation of plastic deformation will eventually lead to failure of the component. The creep behaviour a material exhibits depends upon the magnitude and sign of the prior loading the material was subjected to. This idea was investigated by conducting tests on a section of 316H stainless steel header at 550°C. Both negative and positive plastic strain were applied upon loading followed by load controlled creep to investigate the influence of prior loading upon the accumulation of creep strain. These tests resulted in more creep strain being accumulated after compressive prior loading as opposed to tensile prior loading. This result is significantly influenced by intergranular strains which come from elastic and plastic anisotropy. The experimental results have been compared to the results of an existing crystal plasticity finite element (CPFE) model and there is good agreement between the two sets. Validation of the CPFE model is important for understanding the behaviour of 316H and being able to accurately predict the hysteresis loop this material produces which can provide vital information when conducting life assessments.
Design Methodologies for High Temperature Reactor Structural Components Cladded With Noncompliant Materials
Authors: Barua B. , Phan V.-T. , Messner M. C. , Jetter B. , Sham T.-L. , Wang Y. 
Published: November 2019

Abstract
The existing Class A metallic materials qualified for ASME Section III, Division 5 rules for high temperature nuclear reactors, are not optimized for corrosion resistance when exposed to corrosive reactor coolants such as molten salts, and molten lead and lead-bismuth eutectic. Introducing new corrosion-resistant materials into the Code would be a lengthy and expensive process for long design lifetimes, requiring long-term creep test data. A near-term alternative solution might be to allow designers to clad the existing Class A materials with thin layer of some corrosion-resistant material. However, the current ASME Section III, Division 5 rules provide no guidance on evaluating cladded components against the Code creep-fatigue or strain limits requirements. This necessitates the development of design rules for cladded components that do not require long-term testing of clad materials. Depending on the difference in mechanical properties, the influence of clad on the long term response of the structural system can be significant or negligible. This work focuses on developing design rules for cladded components with a clad material that does not accumulate significant inelastic deformation compared to the base material. This work proposes to treat such clad materials as linear elastic. Sample calculations including finite element analyses of a representative molten salt reactor heat exchanger tube without and with clad were performed to verify the proposed approach. Finally, a complete set of design rules for components with noncompliant clad material is proposed.
Crack Repair Using Hybrid Additive Manufacturing and Friction Stir Processing
Authors: Al-Badour Fadi , Zainelabdeen Ibrahim H. , Suleiman Rami K. , Adesina Akeem 
Published: November 2019

Abstract
A hybrid additive manufacturing (AM) and friction stir processing (FSP) was used to heal a crack in 6 mm thick Al 6061-T6 aluminum alloy. AL-6061 is usually used in H2 high-pressure vessel fabrication as well as aerospace applications. In this work, Al-Si powder was utilized to fill the crack, then FSP was applied to consolidate and stir the powder with the base metal to fill and close the crack zone. Effect of FSP parameters including welding speed and tool rotation speed on the quality of repair was studied. Various mechanical tests, as well as characterization techniques such as hardness test, optical microscopy, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS), were employed to study the newly developed hybrid process on the quality of the repair. The investigation revealed that low rotational speed of 800 rpm results in minimum variation in microhardness. Moreover, the impact of welding speed on microhardness is smaller as compared to rotational speed.
Deformation Behavior and J-Integral of Macroscopic Hydride Platelet Clusters in Hydrided Zr-2.5Nb Pressure Tube Materials Under Plane Strain Conditions
Authors: Wu Shengjia , Pan Jwo , Scarth Douglas A. , St. Lawrence Sterling 
Published: November 2019

Abstract
The mechanical behavior and J-integral of macroscopic hydride platelet clusters in hydrided Zr-2.5Nb pressure tube materials are investigated by two-dimensional finite element analyses with cohesive zone model under plane strain conditions. The hydride platelets are assumed to be separated at the early stage of the loading and are treated as cracks. The cohesive zone model with a trapezoidal traction-separation law is adopted. The macroscopic mechanical behavior is quantified by the macroscopic stress-strain relations and the fracture parameter of the bulk radial hydride is specified by the J integral-stress relations. The hydride platelet spacing has major effects while the cohesive energy and cohesive strength have minor effects on the mechanical behavior and fracture properties of the bulk hydrides. The computational results suggest that the hydride platelet cluster can be viewed as a soft region with a reduced load carrying capacity at large stress under plane strain loading conditions. A hydride platelet cluster may be treated as a cracked bulk hydride but with a reduced crack tip driving force for fracture.
Subsea Intervention System Connector Capacities per the Elastic-Plastic Analysis Methodology
Authors: Sepehri Ali , Bansal Gaurav , Edke Mangesh 
Published: November 2019

Abstract
The offshore oil and gas industry is drilling into and producing from wells in high-pressure, high-temperature (HPHT) environments. This has created a greater demand to develop more advanced tools and new technology to safely overcome the challenges in these operations. Due to the sensitivity and potential impact on the environment, the industry is striving to homogenize the design and acceptance criteria. The API 17G is the industry standard for offshore intervention operations. According to the standard, design verification is performed using finite element analysis (FEA). The standard provides three sets of criteria for determining capacities that adopt the methodologies from ASME Boiler Pressure Vessel Code (BPVC) Section VIII, Div. 3.
The objective of this study is to evaluate tension, pressure, and bending moment capacities per the elastic-plastic analysis methodologies outlined in API 17G for a subsea intervention system connector. The global and local failure capacities are presented for yielding load, plastic collapse, and 2% strain methods. Results indicate that the plastic collapse method is the most conservative approach for evaluating the global capacity of the connector.
Evaluating the Resistance of Austenitic Stainless Steel Welds to Hydrogen Embrittlement
Authors: Ronevich Joseph , San Marchi Chris , Balch Dorian K. 
Published: November 2019

Abstract
Austenitic stainless steels are used extensively in hydrogen gas containment components due to their known resilience in hydrogen environments. Depending on the conditions, degradation can occur in austenitic stainless steels but typically the materials retain sufficient mechanical properties within such extreme environments. In many hydrogen containment applications, it is necessary or advantageous to join components through welding as it ensures minimal gas leakage, unlike mechanical fittings that can become leak paths that develop over time. Over the years many studies have focused on the mechanical behavior of austenitic stainless steels in hydrogen environments and determined their properties to be sufficient for most applications. However, significantly less data have been generated on austenitic stainless steel welds, which can exhibit more degradation than the base material. In this paper, we assess the trends observed in austenitic stainless steel welds tested in hydrogen. Experiments of welds including tensile and fracture toughness testing are assessed and comparisons to behavior of base metals are discussed.
Fatigue of NPP Components Simulated by Non-Uniformly Strained Stainless Steel Specimens
Authors: Solin Jussi , Alhainen Jouni , Arilahti Esko , Seppänen Tommi , Mayinger Wolfgang 
Published: November 2019

Abstract
Comprehensive experimental research on fatigue performance of niobium stabilized (type 347) steel has revealed beneficial effects of hot holds aimed to simulate normal operation of NPP between the fatigue relevant transients. Reduction of plastic strain, extension of life and increase of endurance limit has been demonstrated in strain controlled HCF tests. Our latest results indicate moderate, but still measurable ‘hold effects’ even without any stop of straining and loading, when blocks of low rate cycles are applied between normal frequency straining at constant 325°C.
A new lab testing approach was developed to simulate the ‘component behavior’ in moderate strain concentrations within the NPP primary circuit. Strain concentrations in range of 1.5 ≤ Kε ≤ 2 are simulated through displacement controlled straining of standard and modified geometry LCF specimens. New results confirm the earlier results and introduce another consequence of holds. Cyclic softening promotes localization of strain, but hold hardening reverses this trend. The holds retard strain localization not only within the material microstructure, but also in geometric strain concentrations. We conclude that the geometric delocalization of strain can amplify beneficial hold effects for components. The local strains may reduce below the endurance limit resulting to run-out tests beyond millions of cycles, even though notable values of fatigue usage (CUF) had been accumulated during earlier phases of the tests.
Applicability of the transferability factor introduced in 2013 to the German KTA standard No. 3201.2 is supported. Exact quantification of the factor is not easy, but in all considered cases Fhold ≤ 1. This means that the fatigue usages are overestimated without this factor.