检索结果-南通市图书馆

fatigue strength DETERMINATION OF BUTT WELDED JOINTS BY FEM

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2004年第6期17卷 771-775页

作者： M. Szubryt J. Brózda Instytut Spawalnictwa (Institute of Welding) ul. Bl. Czeslawa 16/18 44-100 Gliwice PolandInstytut Spawalnictwa (Institute of Welding) ul. Bl. Czeslawa 16/18 44-100 Gliwice Poland

The influence of welding parameters of butt joints, made by three processes (MMA, MAG and T.I.M.E), on their geometric characteristics has been evaluated, which in turn caused a change of the fatigue strength. That fore the statistic analysis and FEM were used and a method developed in the Institute of Welding, which consist in a direct connection of parameters used during welding with the fatigue strength of joints welded by various processes. It has been proven, among others, which by using more advanced welding processes (T.I.M.E) the fatigue strength of welded joints can be increased in comparison to joints welded by MMA and MAG.

关键词： fatigue strength fatigue class (FAT) structural stress welded joints

Comparison of the effects of submerged laser peening,cavitation peening and shot peening on the improvement of the fatigue strength of magnesium alloy AZ31

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2023年第5期11卷 1592-1607页

作者： Hitoshi Soyama Chieko Kuji Yiliang Liao Department of Finemechanics Tohoku University6-6-01 AobaAramakiAoba-kuSendai 980-8579Japan Department of Industrial and Manufacturing Systems Engineering Iowa State University2529 Union Dr.AmesIA 50011United States of America

To investigate the improvement in the fatigue strength of magnesium alloy by peening methods,magnesium alloy AZ31 was treated by submerged laser peening(SLP),cavitation peening(CP),and shot peening(SP),and the fatigue properties were evaluated by a plane bending fatigue *** the case of SLP,both the impact induced by laser ablation(LA)and that caused by laser cavitation(LC),which developed after LA,were *** the present study,the fatigue life at a constant bending stress was examined to determine the suitable *** was found that the fatigue strengths at N=10^(7)for the SLP,CP,and SP specimens treated by each optimum condition were 56%,18%,and 16%higher,respectively,than that of the non-peened(NP)specimen,which was 97 *** key factors in the improvement of fatigue strength by peening methods were work hardening and the introduction of compressive residual stress.

关键词： Magnesium alloy fatigue strength Laser peening Cavitation peening Shot peening

Effects of γ-Ray Irradiation on the fatigue strength, Thermal Conductivities and Thermal Stabilities of the Glass Fibres/Epoxy Resins Composites

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2018年第1期31卷 105-112页

作者： Li-Fang Zheng Lu-Ning Wang Zhao-Zhong Wang Li Wang School of Mechanical Engineering University of Science and Technology Beijing School of Materials Science and Engineering University of Science and Technology Beijing

Glass fibres/epoxy resins composites have been performed as ideal materials to make support instruments for high-energy and nuclear physics experiments. The effects of the 3,-ray irradiation on the fatigue strength, thermal conductivities and thermal stabilities of the glass fibres/epoxy resins composites were investigated. And a two-parameter fatigue life model was established to predict the fatigue life of the composites. Results revealed that the y-ray irradiation could probably result in the degradation of epoxy resins, but hardly damage to the glass fibres. And the γ-ray irradiation treatment could significantly affect the fatigue strength of the composites at a low-cycle fatigue stage, but seldom influence at a high-cycle fatigue stage. Furthermore, the fabricated glass fibres/epoxy resins composites after the γ-ray irradiation still presented excellent fatigue strength, ideal thermal conductivities, remarkable dimensional and thermal stabilities, which can meet the actual requirements of normal operation for supporting instruments under high-energy and nuclear physics experiments.

关键词： Epoxy resins composites Glass fibres fatigue strength γ-Ray irradiation Thermal stabilities

High-temperature fatigue strength of grain boundaries with different misorientations in nickel-based superalloy bicrystals

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2023年第23期154卷 94-106页

作者： D.F.Shi Z.J.Zhang Y.H.Yang Y.Z.Zhou R.Liu P.Zhang Z.F.Zhang Shi-changxu Innovation Center for Advanced Materials Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China School of Materials Science and Engineering University of Science and Technology of China Shenyang 110016 China

Nickel-based single-crystal superalloys are widely used in the manufacture of aeroengine turbine vanes for their excellent high-temperature performance. Low-angle grain boundaries (LAGBs) will be generated inevitably during their manufacture, which are often characterized by grain boundary misorientation (GBM) and will weaken the mechanical properties of superalloys. However, the relationship between GBM and the fatigue properties of superalloys at elevated temperatures has seldom been investigated due to the difficulty in the sample preparation and experiment process. Based on six kinds of bicrystals with different tilt LAGBs made by a second-generation single-crystal superalloy, the effects of misorientation on the grain boundary microstructure and fatigue properties (980 °C) of superalloys were studied systematically in this work. It is found that, with the increase of GBM, the GB precipitates combined with the cast micropores increase monotonically, accordingly both the fatigue life and fatigue strength decrease successively. fatigue fracture observations show that the cracks of all the bicrystals initiated from the cast micropores at GBs, and then propagated along the GBs. Therefore, the coupling effect of cast micropores and GBM on the fatigue damage mechanisms of the bicrystals are evaluated according to their hindering degrees on the piled-up dislocations. Combining with a hysteresis energy model, a quantitative fatigue strength prediction model of superalloys is established and is well verified by abundant experimental data. This study could provide guidance for fatigue performance prediction and structural design of superalloys.

关键词： Superalloys Bicrystals Grain boundary misorientation fatigue strength fatigue crack

A practical model for efficient anti-fatigue design and selection of metallic materials:Ⅰ.Model building and fatigue strength prediction

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第11期70卷 233-249页

作者： R.Liu P.Zhang Z.J.Zhang B.Wang Z.F.Zhang Laboratory of fatigue and Fracture for Materials Shi-changxu Innovation Center for Advanced MaterialsInstitute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang 110016China

The high cost and low efficiency of fatigue tests are bottleneck problem for the anti-fatigue design of metallic *** this problem,a theoretical fatigue model is proposed in this study,the possible applications have also been *** results would be introduced in two serial papers,in which the first paper focuses on the model building and the applications on fatigue strength prediction;the second paper put emphasis on the influencing factors of the model parameters and the applications on fatigue strength *** this first paper,a theoretical model is proposed considering both the strength and plastic restrictions of fatigue *** the model builds up a brief relationship among yield strength(Y),tensile strength(T)and fatigue strength(F),it is named as the Y-T-F *** the verification with fatigue strength data covering various kinds of metallic materials and loading conditions,this Y-T-F model exhibits both generality and *** the Y-T-F model,the efficient fatigue strength prediction could be conducted by brief linear fitting and calculation,just through yield strength,tensile strength and several known fatigue strength ***,through its deduced Y-F model,the analytical formula of fatigue strength continuously changing with materials strengthening can be obtained,as well as the maximum value of fatigue strength and corresponding critical yield *** summary,the Y-T-F model would be useful for reducing the fatigue tests,thus providing new possibilities on the efficient anti-fatigue design and selection of metallic materials.

关键词： Yield strength Tensile strength Plasticity fatigue strength Anti-fatigue design

同方期刊数据库

New Developed Welding Electrode for Improving the fatigue strength of Welded Joints

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2002年第6期18卷 527-531页

作者： Wenxian WANG, Lixing HUO, Yufeng ZHANG, Dongpo WANG and Hongyang JINGCollege of Material Science and Engineering, Tianjin University, Tianjin 300072, China Coll. of Mat. Sci. and Eng. Tianjin Univ. Tianjin 300072 China

A new welding electrode, low transformation temperature electrode (LTTE), was introduced in this paper. It was described in design principle, mechanics, chemical compositions of their deposited metal and manufacturing methods. It was proved that the best transformation starting temperature from austenite to martensite of the deposited metal of LTTE was at about 191℃ and it was obtained by adding alloying elements such as Cr, Ni, Mn and Mo. The microstructure of the weld metal of the LTTE was low carbon martensite and residual austenite. The compressive residual stress was induced around the weld of the LTTE and the -145 MPa in compression could be obtained in middle of weld metal. The fatigue tests showed that the fatigue strength of the longitudinal welded joints welded with the LTTE at 2×106 cycles was improved by 59% compared with that of the same type of welded joints welded with conventional E5015 and the fatigue life was increased by 47 times at 162 MPa. It is a very valuable method to improve the fatigue performance of welded joints.

关键词： Low transformation temperature electrode Compressive residual stress fatigue strength Welded joints

Flexural fatigue strength of steel fibrous concrete containing mixed steel fibres

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第8期7卷 1329-1335页

作者： SINGH S.P. MOHAMMADI Y. MADAN S.K. Civil Engineering National Institute of Technology Jalandhar 144 011 India Civil Engineering University of Mohaghegh Ardebili Ardebil 179 Iran Civil Engineering National Institute of Technology Kurukushetra 136 119 India

This paper reports investigation conducted to study the fatigue performance of steel fibre reinforced concrete (SFRC) containing fibres of mixed aspect ratio. An extensive experimental program was conducted in which 90 flexural fatigue tests were carried out at different stress levels on size 500 mm×100 mm×100 mm SFRC specimens respectively containing 1.0%, 1.5% and 2.0% volume fraction of fibres. About 36 static flexural tests were also conducted to determine the static flexural strength prior to fatigue testing. Each volume fraction of fibres incorporated corrugated mixed steel fibres of size 0.6 mm×2.0 mm×25 mm and 0.6 mm×2.0 mm×50 mm in ratio 50:50 by weight. The results are presented both as S-N relationships, with the maximum fatigue stress expressed as a percentage of the strength under static loading, and as relationships between actually applied fatigue stress and number of loading cycles to failure. Two-million-cycle fatigue strengths of SFRC containing different volume fractions of mixed fibres were obtained and compared with plain concrete.

关键词： fatigue strength Static flexural strength Stress level Stress ratio Steel fibre reinforced concrete (SFRC)

Assessment of fatigue strength of An Offshore Floating Production and Storage Unit

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2002年第1期17卷 41-49页

作者： LIU Jiancheng(刘建成) GU Yongning(顾永宁) School of Naval Architecture and Ocean Engineering Shanghai Jiootong University Shanghai 200030 China School of Naval Architecture and Ocean Engineering Shanghai Jiootong University Shanghai 200030 China

The procedure of assessment of structural fatigue strength of an offshore floating production and storage and offloading unit (FPSO) in this paper. The emphasis is placed on the long-term prediction of wave induced loading, the refined finite element model for hot spot stress calculation, the combination of stress components, and fatigue damage assessment based on S-N curve.

关键词： offshore structure fatigue strength hot spot stress long-term prediction floating production and storage and offloading unit

Effect of welding with trailing rotating extrusion on fatigue strength of aluminum alloy welded joints

在线全文

学校读者我要写书评

暂无评论

China Welding 2011年第3期20卷 47-51页

作者：李军杨建国张文锋王萍方洪渊 State Key Laboratory of Advanced Welding Production Technology Harbin Institute of Technology Harbin 150001

Welding with trailing rotating extrusion is a new method designed to improve the welding quality of aluminum alloy thin-plate weldments. The effect of this technology on fatigue strength of aluminum alloy welded joints was investigated and analyzed in this paper. Experimental data show that welding with trailing rotating extrusion can improve the fatigue strength of aluminum alloy weldments remarkably,

关键词： welding rotating extrusion aluminum alloy fatigue strength