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Transient analysis of thermoelastic contact problem of disk brakes
Ali BELHOCINE, Mostefa BOUCHETARA
《机械工程前沿(英文)》 2013年 第8卷 第2期 页码 150-159 doi: 10.1007/s11465-013-0266-6
The main purpose of this study is to analyze the thermomechanical behavior of the dry contact between the brake disk and pads during the braking phase. The simulation strategy is based on computer code ANSYS11. The modeling of transient temperature in the disk is actually used to identify the factor of geometric design of the disk to install the ventilation system in vehicles. The thermal-structural analysis is then used with coupling to determine the deformation established and the Von Mises stresses in the disk, the contact pressure distribution in pads. The results are satisfactory compared to those found in the literature.
关键词: brake disks heat flux heat-transfer coefficient Von Mises stress contact pressure
Investigating peak stresses in fitting and repair patches of buried polyethylene gas pipes
Reza KHADEMI ZAHEDI, Pouyan ALIMOURI, Hooman KHADEMI ZAHEDI, Mohammad SHISHESAZ
《结构与土木工程前沿(英文)》 2020年 第14卷 第1期 页码 147-168 doi: 10.1007/s11709-019-0587-6
关键词: Ansys software polyethylene buried pipelines polyethylene joints polyethylene patches peak von Mises stress soil-pipe interaction temperature variation
Adaptive selective ES-FEM limit analysis of cracked plane-strain structures
H. NGUYEN-XUAN,T. RABCZUK
《结构与土木工程前沿(英文)》 2015年 第9卷 第4期 页码 478-490 doi: 10.1007/s11709-015-0317-7
关键词: cracked structure limit analysis von Mises criterion edge-based strain smoothing second-order cone programming adaptive
Epidemiological study of a von Hippel-Lindau family in northwest China
null
《医学前沿(英文)》 2013年 第7卷 第3期 页码 378-385 doi: 10.1007/s11684-013-0276-0
von Hippel-Lindau (VHL) disease is a rare, inherited neoplastic disease characterized by hemangioblastomas (HBL) of the central nervous system (CNS), retinal angiomas, renal cell carcinomas (RCC), pancreatic endocrine tumors (PETs), pheochromocytomas, paragangliomas, and visceral cysts. We encountered a large VHL family in northwest China and conducted a systematic screening of the family members based on their epidemiological and clinical characteristics. A self-designed questionnaire was used to collect the general sociodemographic and health information of the family members. For the preliminary family screening, physical examination and abdomen B ultrasonography were performed. The suspected patients were subjected to cranial computerized tomography and fundus examination. The clinical data of the patients with confirmed VHL disease were collected from hospital records. A total of 63 lineal descendants in six generations were observed in the family (generations O, A, B, C, D, E), including 9 dead suspected cases (6 males, 3 females) and 10 living cases (2 males, 8 females). Among the 10 living cases, 4, 2, 1, 3, 4, 8, and 2 manifested HBLs of the CNS, PETs, RCC, pancreatic cysts, renal cysts, pheochromocytomas (4 hemi and 4 bilateral), and paragangliomas, respectively. Data showed that the morbidity of VHL disease in generation C was lower than that in generation B, but the age of onset was younger. This study is the first to report VHL disease in northwest China and VHL-associated PET cases in Chinese. Therefore, follow-up checkups of the family should be focused on younger generations. Proper family screening protocols should be followed for the treatment of patients with VHL disease.
关键词: von Hippel-Lindau disease epidemiology family screening pancreatic endocrine tumor
Elasto-plastic fatigue crack growth analysis of plane problems in the presence of flaws using XFEM
Sachin KUMAR,A. S. SHEDBALE,I. V. SINGH,B. K. MISHRA
《结构与土木工程前沿(英文)》 2015年 第9卷 第4期 页码 420-440 doi: 10.1007/s11709-015-0305-y
关键词: XFEM von-Mises yield criterion isotropic hardening fatigue crack growth J-integral
Andrew LOCKLEY, Ted von HIPPEL
《工程管理前沿(英文)》 2021年 第8卷 第3期 页码 456-464 doi: 10.1007/s42524-020-0102-8
关键词: carbon dioxide removal Liquid Air Energy Storage Compressed Air Energy Storage geoengineering
The epidemiology of norovirus gastroenteritis in China: disease burden and distribution of genotypes
Honglu Zhou, Songmei Wang, Lorenz von Seidlein, Xuanyi Wang
《医学前沿(英文)》 2020年 第14卷 第1期 页码 1-7 doi: 10.1007/s11684-019-0733-5
关键词: molecular epidemiology norovirus disease burden genotype China
EFFECTS OF TRANSPORT STRESS ON THE INTESTINES INVOLVING NEURONAL NITRIC OXIDE SYNTHASE
《农业科学与工程前沿(英文)》 页码 285-295 doi: 10.15302/J-FASE-2022469
● Transport stress declined the level of leukocytes including lymphocytes in rat serum.
Analysis on annealing-induced stress of blind-via TSV using FEM
Jie SHAO, Tielin SHI, Li DU, Lei SU, Xiangning LU, Guanglan LIAO
《机械工程前沿(英文)》 2018年 第13卷 第3期 页码 401-410 doi: 10.1007/s11465-017-0457-7
Copper-filled through silicon via (TSV) is a promising material owing to its application in high-density three-dimensional (3D) packaging. However, in TSV manufacturing, thermo-mechanical stress is induced during the annealing process, often causing reliability issues. In this paper, the finite element method is employed to investigate the impacts of via shape and SiO2 liner uniformity on the thermo-mechanical properties of copper-filled blind-via TSV after annealing. Top interface stress analysis on the TSV structure shows that the curvature of via openings releases stress concentration that leads to ~60 MPa decrease of normal stresses, sxx and syy, in copper and ~70 MPa decrease sxx of in silicon. Meanwhile, the vertical interface analysis shows that annealing-induced stress at the SiO2/Si interface depends heavily on SiO2 uniformity. By increasing the thickness of SiO2 linear, the stress at the vertical interface can be significantly reduced. Thus, process optimization to reduce the annealing-induced stress becomes feasible. The results of this study help us gain a better understanding of the thermo-mechanical behavior of the annealed TSV in 3D packaging.
关键词: through silicon via (TSV) annealing-induced stress interface stress plastic deformation finite element method
Extrapolation reconstruction of wind pressure fields on the claddings of high-rise buildings
Yehua SUN, Guquan SONG, Hui LV
《结构与土木工程前沿(英文)》 2019年 第13卷 第3期 页码 653-666 doi: 10.1007/s11709-018-0503-5
关键词: extrapolation reconstruction proper orthogonal decomposition Kriging method von Kármán function Hurst exponent rescaled range analysis
An investigation on stress distribution effect on multi- piezoelectric energy harvesters
Hailu YANG, Dongwei CAO
《结构与土木工程前沿(英文)》 2017年 第11卷 第3期 页码 301-307 doi: 10.1007/s11709-017-0404-z
关键词: piezoelectric transducer uneven stress impedance matching optimal energy output
The formation mechanism and the influence factor of residual stress in machining
null
《机械工程前沿(英文)》 2014年 第9卷 第3期 页码 265-269 doi: 10.1007/s11465-014-0311-0
Residual stresses generated in cutting process have important influences on workpiece performance. The paper presents a method of theoretical analysis in order to explicate the formation mechanism of residual stresses in cutting. An important conclusion is drawn that the accumulated plastic strain is the main factor which determines the nature and the magnitude of surface residual stresses in the workpiece. On the basis of the analytical model for residual stress, a series of simulations for residual stress prediction during cutting AISI 1045 steel are implemented in order to obtain the influences of cutting speed, depth of cut and tool edge radius on surface residual stress in the workpiece. And these influences are explained from the perspective of formation mechanism of residual stress in cutting. The conclusions have good applicability and can be used to guide the parameters selection in actual production.
关键词: residual stress analytical model strain plastic cutting parameter
张亦良,徐金泉,王羽辞
《中国工程科学》 2009年 第11卷 第8期 页码 38-43
针对石化特种设备中硫化氢(H2S)应力腐蚀问题现状,综合比较了国际权威机构NACE,EFC以及ISO发布的最新标准、规范,对H2S应力腐蚀的环境界定、试验方法、影响因素、应力腐蚀评价准则及对材料的要求等做了扼要的综述。同时对焊接残余应力的产生、测定方法、消除措施等进行了论述,列举了实际参与研究的发生应力腐蚀容器的实例及残余应力的影响。
Magnetostriction varieties and stress relief caused by pulsed magnetic field
Zhipeng CAI, Xinjie DUAN, Jian LIN, Haiyan ZHAO
《机械工程前沿(英文)》 2011年 第6卷 第3期 页码 354-358 doi: 10.1007/s11465-011-0123-4
Magnetostriction is investigated to evaluate the stress relief caused by pulsed magnetic field treatment, because this physical property is closely associated with residual stress. Magnetostriction of different stressed samples is measured in this paper. The stress variations caused by pulsed magnetic treatment are also compared. It is found that magnetostriction variations are closely associated with stress changes. Thermodynamic potential is used to find the relationship between them. Based on several assumptions, we find that the product of magnetostriction amplitude and stress magnitude is nearly a constant during magnetic field treatment, which is valuable for stress relief evaluation and optimizing processing parameters. This conclusion is testified by stress measurements, and the calculated values are in accordance with the experiment results.
关键词: magnetostriction pulsed magnetic field treatment stress relief
Elastic modulus and thermal stress in coating during heat cycling with different substrate shapes
Daniel GAONA,Alfredo VALAREZO
《机械工程前沿(英文)》 2015年 第10卷 第3期 页码 294-300 doi: 10.1007/s11465-015-0351-0
The elastic modulus of a deposit (Ed) can be obtained by monitoring the temperature (?T) and curvature (?k) of a one-side coated long plate, namely, a one-dimensional (1D) deformation model. The aim of this research is to design an experimental setup that proves whether a 1D deformation model can be scaled for complex geometries. The setup includes a laser displacement sensor mounted on a robotic arm capable of scanning a specimen surface and measuring its deformation. The reproducibility of the results is verified by comparing the present results with Stony Brook University Laboratory’s results. The ?k-?T slope error is less than 8%, and the Ed estimation error is close to 2%. These values reveal the repeatability of the experiments. Several samples fabricated with aluminum as the substrate and 100MXC nanowire (Fe and Cr alloy) as the deposit are analyzed and compared with those in finite element (FE) simulations. The linear elastic behavior of 1D (flat long plate) and 2D (squared plate) specimens during heating/cooling cycles is demonstrated by the high linearity of all ?k-?T curves (over 97%). The Ed values are approximately equal for 1D and 2D analyses, with a median of 96 GPa and standard deviation of 2 GPa. The correspondence between the experimental and simulated results for the 1D and 2D specimens reveals that deformation and thermal stress in coated specimens can be predicted regardless of specimen geometry through FE modeling and by using the experimental value of Ed. An example of a turbine-blade-shaped substrate is presented to validate the approach.
关键词: in-plane Young’s modulus curvature temperature thermal stress coating
标题 作者 时间 类型 操作
Transient analysis of thermoelastic contact problem of disk brakes
Ali BELHOCINE, Mostefa BOUCHETARA
期刊论文
Investigating peak stresses in fitting and repair patches of buried polyethylene gas pipes
Reza KHADEMI ZAHEDI, Pouyan ALIMOURI, Hooman KHADEMI ZAHEDI, Mohammad SHISHESAZ
期刊论文
Adaptive selective ES-FEM limit analysis of cracked plane-strain structures
H. NGUYEN-XUAN,T. RABCZUK
期刊论文
Elasto-plastic fatigue crack growth analysis of plane problems in the presence of flaws using XFEM
Sachin KUMAR,A. S. SHEDBALE,I. V. SINGH,B. K. MISHRA
期刊论文
The carbon dioxide removal potential of Liquid Air Energy Storage: A high-level technical and economic appraisal
Andrew LOCKLEY, Ted von HIPPEL
期刊论文
The epidemiology of norovirus gastroenteritis in China: disease burden and distribution of genotypes
Honglu Zhou, Songmei Wang, Lorenz von Seidlein, Xuanyi Wang
期刊论文
Analysis on annealing-induced stress of blind-via TSV using FEM
Jie SHAO, Tielin SHI, Li DU, Lei SU, Xiangning LU, Guanglan LIAO
期刊论文
Extrapolation reconstruction of wind pressure fields on the claddings of high-rise buildings
Yehua SUN, Guquan SONG, Hui LV
期刊论文
An investigation on stress distribution effect on multi- piezoelectric energy harvesters
Hailu YANG, Dongwei CAO
期刊论文
Magnetostriction varieties and stress relief caused by pulsed magnetic field
Zhipeng CAI, Xinjie DUAN, Jian LIN, Haiyan ZHAO
期刊论文