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Recent development in low-constraint fracture toughness testing for structural integrity assessment of

Jidong KANG, James A. GIANETTO, William R. TYSON

《机械工程前沿(英文)》 2018年 第13卷 第4期   页码 546-553 doi: 10.1007/s11465-018-0501-2

摘要:

Fracture toughness measurement is an integral part of structural integrity assessment of pipelines. Traditionally, a single-edge-notched bend (SE(B)) specimen with a deep crack is recommended in many existing pipeline structural integrity assessment procedures. Such a test provides high constraint and therefore conservative fracture toughness results. However, for girth welds in service, defects are usually subjected to primarily tensile loading where the constraint is usually much lower than in the three-point bend case. Moreover, there is increasing use of strain-based design of pipelines that allows applied strains above yield. Low-constraint toughness tests represent more realistic loading conditions for girth weld defects, and the corresponding increased toughness can minimize unnecessary conservatism in assessments. In this review, we present recent developments in low-constraint fracture toughness testing, specifically using single-edge-notched tension specimens, SENT or SE(T). We focus our review on the test procedure development and automation, round-robin test results and some common concerns such as the effect of crack tip, crack size monitoring techniques, and testing at low temperatures. Examples are also given of the integration of fracture toughness data from SE(T) tests into structural integrity assessment.

关键词: fracture toughness     constraint effect     single-edge-notched tension test     pipeline     structural integrity assessment    

Local fracture properties and dissimilar weld integrity in nuclear power plants

Guozhen WANG, Haitao WANG, Fuzhen XUAN, Shantung TU, Changjun LIU

《机械工程前沿(英文)》 2013年 第8卷 第3期   页码 283-290 doi: 10.1007/s11465-013-0250-1

摘要:

In this paper, the local fracture properties in a Alloy52M dissimilar metal welded joint (DMWJ) between A508 ferritic steel and 316 L stainless steel in nuclear power plants were investigated by using the single-edge notched bend (SENB) specimens, and their use in integrity assessment of DMWJ structures was analyzed. The results show that the local fracture resistance in the DMWJ is determined by local fracture mechanism, and which is mainly related to the microstructures and local strength mismatches of materials at the crack locations. The initial cracks always grow towards the materials with lower strength, and the crack path deviation is mainly controlled by the local strength mismatch. If the local fracture properties could not be used for cracks in the heat affected zones (HAZs), interface and near interface zones, the use of the fracture properties ( -resistance curves) of base metals or weld metals following present codes will unavoidably produce non-conservative (unsafe) or excessive conservative assessment results. In most cases, the assessment results will be potentially unsafe. Therefore, it is recommended to obtain and use local mechanical and fracture properties in the integrity assessment of DMWJs.

关键词: local fracture properties     dissimilar metal welded joint     integrity assessment     strength mismatch     crack growth path    

An Exploration of Surface Integrity Remanufacturing for Aeroengine Components

Qiao Xiang,Yong He,Ting-hong Hou

《工程管理前沿(英文)》 2016年 第3卷 第2期   页码 107-114 doi: 10.15302/J-FEM-2016025

摘要: Surface integrity is the major factor impacting on the operation quality, service life and reliability of the aeroengine components. The surface integrity of aeroengine component is damaged by the failures such as crack, deformation, oxidation, corrosion, erosion, and microstructural degeneration. It adopts advanced remanufacturing technologies to restore or improve the surface integrity and regenerate these high value parts. This paper firstly puts forward the concept, namely surface integrity remanufacturing for aeroengine components, and its connotation. The key remanufacturing technologies have been developed to repair the components with surface damages. Ultimately, some application examples of surface integrity remanufacturing technologies as well as their effects in aeroengine maintenance are introduced. The discarded components have been reused and their service lives have been extended and their reliability has been increased by implementing surface integrity remanufacturing. It has realized “The Repaired Components Outpacing the New Ones”, material saving, energy saving, and emission reduction.

关键词: aeroengine component     surface integrity     remanufacturing     surface integrity remanufacturing    

Emerging challenges to structural integrity technology for high-temperature applications

TU Shantung

《机械工程前沿(英文)》 2007年 第2卷 第4期   页码 375-387 doi: 10.1007/s11465-007-0066-y

摘要: Structural integrity technology has been widely used with great success for the design, manufacture and failure prevention of modern constructions such as chemical and petrochemical plants, power generation and energy conversion systems, as well as space and oceanic exploration. The modern needs of structural integrity technology are largely attributed to the increase of service temperature of the structures that results in the efficiency improvement in energy conversion and chemical processing technologies. Besides the needs arising from large-scale high-temperature plants, the high tech developments, such as micro chemo-mechanical systems and high-power electronics, provide new challenges to structural integrity technology. The present paper summarizes the recent technical progresses in large process plants and the aviation industry, micro chemo-mechanical systems, fuel cells, high-temperature electronics, and packaging and coating technologies. The state-of-the-art of structural integrity technology for high temperature applications is reviewed. Suggestions are provided for the improvement of current design and assessment methods.

关键词: manufacture     aviation industry     conversion     petrochemical     temperature    

How does the improved DB mode degrade the complex integrity of infrastructure mega-projects?

Jinwen ZHANG, Yumin QIU

《工程管理前沿(英文)》 2018年 第5卷 第1期   页码 40-51 doi: 10.15302/J-FEM-2018083

摘要: Complex integrity is one of the main characteristics of infrastructure mega-projects (IMPs). Cost, technology, risk, duration, environmental impact, and other uncertain complexities are interrelated and constitute a challenging and complex management problem. At present, there is no unified understanding of or solutions to these complex integrity problems. This study analyzes the complex integrity of the island-tunnel subproject of the Hong Kong-Zhuhai-Macao Bridge (HZMB) project and proposes an improved design-build (DB) mode in which the owner provides a preliminary design and has the right to form and manage consortium. This improved DB mode creatively degrades the special complexities that arise from multiple dimensions. On this basis, it is an efficacious way to grasp the main contradictions, integrate the effective resources, and degrade the complex integrity in multiple dimensions and at multiple levels so as to effectively deal with the complexity management of IMPs.

关键词: Hong Kong-Zhuhai-Macao Bridge project     island-tunnel subproject     complex integrity     complexity degradation     the general contracting mode of design-build     the design-build consortium    

Propagation characteristics of transient waves in low-strain integrity testing on cast-in-situ concrete

Hanlong LIU, Xuanming DING

《结构与土木工程前沿(英文)》 2009年 第3卷 第2期   页码 240-240 doi: 10.1007/s11709-009-0100-8

Experimental study of surface integrity and fatigue life in the face milling of Inconel 718

Xiangyu WANG, Chuanzhen HUANG, Bin ZOU, Guoliang LIU, Hongtao ZHU, Jun WANG

《机械工程前沿(英文)》 2018年 第13卷 第2期   页码 243-250 doi: 10.1007/s11465-018-0479-9

摘要:

The Inconel 718 alloy is widely used in the aerospace and power industries. The machining-induced surface integrity and fatigue life of this material are important factors for consideration due to high reliability and safety requirements. In this work, the milling of Inconel 718 was conducted at different cutting speeds and feed rates. Surface integrity and fatigue life were measured directly. The effects of cutting speed and feed rate on surface integrity and their further influences on fatigue life were analyzed. Within the chosen parameter range, the cutting speed barely affected the surface roughness, whereas the feed rate increased the surface roughness through the ideal residual height. The surface hardness increased as the cutting speed and feed rate increased. Tensile residual stress was observed on the machined surface, which showed improvement with the increasing feed rate. The cutting speed was not an influencing factor on fatigue life, but the feed rate affected fatigue life through the surface roughness. The high surface roughness resulting from the high feed rate could result in a high stress concentration factor and lead to a low fatigue life.

关键词: roughness     hardness     residual stress     microstructure     fatigue life    

Fiber-reinforced composites in milling and grinding: machining bottlenecks and advanced strategies

《机械工程前沿(英文)》 2022年 第17卷 第2期 doi: 10.1007/s11465-022-0680-8

摘要: Fiber-reinforced composites have become the preferred material in the fields of aviation and aerospace because of their high-strength performance in unit weight. The composite components are manufactured by near net-shape and only require finishing operations to achieve final dimensional and assembly tolerances. Milling and grinding arise as the preferred choices because of their precision processing. Nevertheless, given their laminated, anisotropic, and heterogeneous nature, these materials are considered difficult-to-machine. As undesirable results and challenging breakthroughs, the surface damage and integrity of these materials is a research hotspot with important engineering significance. This review summarizes an up-to-date progress of the damage formation mechanisms and suppression strategies in milling and grinding for the fiber-reinforced composites reported in the literature. First, the formation mechanisms of milling damage, including delamination, burr, and tear, are analyzed. Second, the grinding mechanisms, covering material removal mechanism, thermal mechanical behavior, surface integrity, and damage, are discussed. Third, suppression strategies are reviewed systematically from the aspects of advanced cutting tools and technologies, including ultrasonic vibration-assisted machining, cryogenic cooling, minimum quantity lubrication (MQL), and tool optimization design. Ultrasonic vibration shows the greatest advantage of restraining machining force, which can be reduced by approximately 60% compared with conventional machining. Cryogenic cooling is the most effective method to reduce temperature with a maximum reduction of approximately 60%. MQL shows its advantages in terms of reducing friction coefficient, force, temperature, and tool wear. Finally, research gaps and future exploration directions are prospected, giving researchers opportunity to deepen specific aspects and explore new area for achieving high precision surface machining of fiber-reinforced composites.

关键词: milling     grinding     fiber-reinforced composites     damage formation mechanism     delamination     material removal mechanism     surface integrity     minimum quantity lubrication    

is essential for the integrity of stereociliary rootlet in cochlear hair cells in mice

Yuqin Men, Xiujuan Li, Hailong Tu, Aizhen Zhang, Xiaolong Fu, Zhishuo Wang, Yecheng Jin, Congzhe Hou, Tingting Zhang, Sen Zhang, Yichen Zhou, Boqin Li, Jianfeng Li, Xiaoyang Sun, Haibo Wang, Jiangang Gao

《医学前沿(英文)》 2019年 第13卷 第6期   页码 690-704 doi: 10.1007/s11684-018-0638-8

摘要: encodes the taperin protein, which is concentrated in the tapered region of hair cell stereocilia in the inner ear. In humans, mutations cause autosomal recessive nonsyndromic deafness (DFNB79) by an unknown mechanism. To determine the role of in hearing, we generated -null mice by clustered regularly interspaced short palindromic repeat/Cas9 genome-editing technology from a CBA/CaJ background. We observed significant hearing loss and progressive degeneration of stereocilia in the outer hair cells of -null mice starting from postnatal day 30. Transmission electron microscopy images of stereociliary bundles in the mutant mice showed some stereociliary rootlets with curved shafts. The central cores of the stereociliary rootlets possessed hollow structures with surrounding loose peripheral dense rings. Radixin, a protein expressed at stereocilia tapering, was abnormally dispersed along the stereocilia shafts in null mice. The expression levels of radixin and -actin significantly decreased. We propose that is critical to the retention of the integrity of the stereociliary rootlet. Loss of in -null mice caused the disruption of the stereociliary rootlet, which resulted in damage to stereociliary bundles and hearing impairments. The generated -null mice are ideal models of human hereditary deafness DFNB79.

关键词: TPRN     stereocilia     stereociliary rootlet     actin filament     CRISPR/Cas9     hearing    

Structural pavement assessment in Germany

Lutz PINKOFSKY, Dirk JANSEN

《结构与土木工程前沿(英文)》 2018年 第12卷 第2期   页码 183-191 doi: 10.1007/s11709-017-0412-z

摘要: The aging structure as well as the considerable increase of heavy-traffic load on Germany’s motorways and trunk roads encourages the use of innovative, sound and reliable methods for the structural assessment on network level as well as on project level. Essential elements for this are data, which allow a reliable assessment. For a holistic approach to structural pavement assessment performance orientated measurements will be necessary. In combination with functional parameters as well as write-down models, strategically motivated decision making processes will be useful combined with technically motivated decision processes. For the application at the network level, the available methods for performance orientated measurements are still challenging, as they are based either on testing drill-cores or on non-traffic speed methods. In recent years significant innovation steps have been made to bring traffic speed bearing capacity measurements and methods for evaluating pavement structures on the road. The paper summarizes the actual assessment procedures in Germany as well as the ongoing work on the development and implementation of new methods and techniques.

关键词: pavement assessment     Germany     structure     system    

表面完整性研究的进展与展望

房丰洲, 顾春阳, 郝然, 游开元, 黄思雨

《工程(英文)》 2018年 第4卷 第6期   页码 754-758 doi: 10.1016/j.eng.2018.11.005

Vibration characteristics and machining performance of a novel perforated ultrasonic vibration platform in the grinding of particulate-reinforced titanium matrix composites

《机械工程前沿(英文)》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0730-2

摘要: Ultrasonic vibration-assisted grinding (UVAG) is an advanced hybrid process for the precision machining of difficult-to-cut materials. The resonator is a critical part of the UVAG system. Its performance considerably influences the vibration amplitude and resonant frequency. In this work, a novel perforated ultrasonic vibration platform resonator was developed for UVAG. The holes were evenly arranged at the top and side surfaces of the vibration platform to improve the vibration characteristics. A modified apparent elasticity method (AEM) was proposed to reveal the influence of holes on the vibration mode. The performance of the vibration platform was evaluated by the vibration tests and UVAG experiments of particulate-reinforced titanium matrix composites. Results indicate that the reasonable distribution of holes helps improve the resonant frequency and vibration mode. The modified AEM, the finite element method, and the vibration tests show a high degree of consistency for developing the perforated ultrasonic vibration platform with a maximum frequency error of 3%. The employment of ultrasonic vibration reduces the grinding force by 36% at most, thereby decreasing the machined surface defects, such as voids, cracks, and burnout.

关键词: ultrasonic vibration-assisted grinding     perforated ultrasonic vibration platform     vibration characteristics     apparent elasticity method     grinding force     surface integrity    

Environmental and human health impact assessment of major interior wall decorative materials

Bingqing ZHANG, Ruochen ZENG, Xiaodong LI

《工程管理前沿(英文)》 2019年 第6卷 第3期   页码 406-415 doi: 10.1007/s42524-019-0025-4

摘要: Despite the growing interest in green products in the interior wall decorative material market, knowledge gaps exist because determining which product is more environmental and user friendly than the others is difficult. This work assesses the environmental and human health profiles of interior latex and wallpaper. Two interior latex products of different raw material ratios and one non-woven wallpaper product are considered. The environmental impact assessment follows life cycle assessment (LCA) methodology and applies Building Environmental Performance Analysis System (BEPAS). The human health impact is based on impact-pathway chain and is performed using Building Health Impact Analysis System (BHIAS). The assessment scope, associated emissions, and territorial scope of various emissions are defined to facilitate comparison study of interior wall decorative products. The impacts are classified into 15 categories belonging to three safeguard areas: ecological environment, natural resources, and human health. The impacts of categories are calculated and monetized using willingness to pay (WTP) and disability-adjusted life year (DALY) and summarized as an integrated external cost of environmental and human health impacts. Assessment results reveal that the integrated impact of interior latex is lower than that of non-woven wallpaper, and the interior latex of low quality causes low life cycle integrated impact. The most impacted categories are global warming, respiratory effects, and water consumption. Hotspots of product manufacturing are recognized to promote green product design.

关键词: life cycle assessment     human health impact     integrated assessment     interior wall decorative material     green product    

SUSTAINABLE NITROGEN MANAGEMENT INDEX: DEFINITION, GLOBAL ASSESSMENT AND POTENTIAL IMPROVEMENTS

《农业科学与工程前沿(英文)》 2022年 第9卷 第3期   页码 356-365 doi: 10.15302/J-FASE-2022458

摘要:

● A composite N management index is proposed to measure agriculture sustainability.

关键词: global assessment     indicator     nitrogen management     sustainable agriculture     sustainable development goals    

Game theoretic analysis of environmental impact assessment system in China

CHENG Hongguang, PU Xiao, GONG Li, QI Ye

《环境科学与工程前沿(英文)》 2007年 第1卷 第4期   页码 448-453 doi: 10.1007/s11783-007-0071-8

摘要: Environmental impact assessment (EIA) system has been established in China since 1973. In present EIA cases, there are four participants in general: governments, enterprises, EIA organizations and the public. The public has held re

关键词: public     impact assessment     Environmental impact     general    

标题 作者 时间 类型 操作

Recent development in low-constraint fracture toughness testing for structural integrity assessment of

Jidong KANG, James A. GIANETTO, William R. TYSON

期刊论文

Local fracture properties and dissimilar weld integrity in nuclear power plants

Guozhen WANG, Haitao WANG, Fuzhen XUAN, Shantung TU, Changjun LIU

期刊论文

An Exploration of Surface Integrity Remanufacturing for Aeroengine Components

Qiao Xiang,Yong He,Ting-hong Hou

期刊论文

Emerging challenges to structural integrity technology for high-temperature applications

TU Shantung

期刊论文

How does the improved DB mode degrade the complex integrity of infrastructure mega-projects?

Jinwen ZHANG, Yumin QIU

期刊论文

Propagation characteristics of transient waves in low-strain integrity testing on cast-in-situ concrete

Hanlong LIU, Xuanming DING

期刊论文

Experimental study of surface integrity and fatigue life in the face milling of Inconel 718

Xiangyu WANG, Chuanzhen HUANG, Bin ZOU, Guoliang LIU, Hongtao ZHU, Jun WANG

期刊论文

Fiber-reinforced composites in milling and grinding: machining bottlenecks and advanced strategies

期刊论文

is essential for the integrity of stereociliary rootlet in cochlear hair cells in mice

Yuqin Men, Xiujuan Li, Hailong Tu, Aizhen Zhang, Xiaolong Fu, Zhishuo Wang, Yecheng Jin, Congzhe Hou, Tingting Zhang, Sen Zhang, Yichen Zhou, Boqin Li, Jianfeng Li, Xiaoyang Sun, Haibo Wang, Jiangang Gao

期刊论文

Structural pavement assessment in Germany

Lutz PINKOFSKY, Dirk JANSEN

期刊论文

表面完整性研究的进展与展望

房丰洲, 顾春阳, 郝然, 游开元, 黄思雨

期刊论文

Vibration characteristics and machining performance of a novel perforated ultrasonic vibration platform in the grinding of particulate-reinforced titanium matrix composites

期刊论文

Environmental and human health impact assessment of major interior wall decorative materials

Bingqing ZHANG, Ruochen ZENG, Xiaodong LI

期刊论文

SUSTAINABLE NITROGEN MANAGEMENT INDEX: DEFINITION, GLOBAL ASSESSMENT AND POTENTIAL IMPROVEMENTS

期刊论文

Game theoretic analysis of environmental impact assessment system in China

CHENG Hongguang, PU Xiao, GONG Li, QI Ye

期刊论文