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APPLICATION OF SUB-ELEMENT AND MICRO-ELEMENT IN BEM WITH ROLLER BEARING LOAD 被引量:5
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作者 ShuXuedao XingXidong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2004年第3期423-426,共4页
Aiming at the discontinuous traction on contact elements of roller bearing,new concepts of sub- and micro-element are put forward. In the sub-element and micro-element,traction influence coefficient has been modified,... Aiming at the discontinuous traction on contact elements of roller bearing,new concepts of sub- and micro-element are put forward. In the sub-element and micro-element,traction influence coefficient has been modified, which is calculated by the former boundary elementmethod (BEM) with roller bearing load. Hence, three-dimensional distribution of load on rollerbearing is calculated accurately. In practice, it has been proved that this method has highercalculation accuracy. An effective numerical method is offered for analyzing load characteristics ofroller bearing to improve service longevity of roller bearing and operation efficiency of rollingmill. 展开更多
关键词 Sub-element micro-element BEM
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Three-dimensional Finite Element Modeling of a Maxillary Premolar Tooth Based on the Micro-CT Scanning: A Detailed Description 被引量:5
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作者 黄政 陈智 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2013年第5期775-779,共5页
This study describes the details of how to construct a three-dimensional (3D) finite element model of a maxillary first premolar tooth based on micro-CT data acquisition technique, MIMICS soft- ware and ANSYS softwa... This study describes the details of how to construct a three-dimensional (3D) finite element model of a maxillary first premolar tooth based on micro-CT data acquisition technique, MIMICS soft- ware and ANSYS software. The tooth was scanned by micro-CT, in which 1295 slices were obtained and then 648 slices were selected for modeling. The 3D surface mesh models of enamel and dentin were created by MIMICS (STL file). The solid mesh model was constructed by ANSYS. After the material properties and boundary conditions were set, a loading analysis was performed to demonstrate the ap- plicableness of the resulting model. The first and third principal stresses were then evaluated. The re- suits showed that the number of nodes and elements of the finite element model were 56 618 and 311801, respectively. The geometric form of the model was highly consistent with that of the true tooth, and the deviation between them was ~).28%. The loading analysis revealed the typical stress patterns in the contour map. The maximum compressive stress existed in the contact points and the maximum tensile stress existed in the deep fissure between the two cusps. It is concluded that by using the micro-CT and highly integrated software, construction of the 3D finite element model with high quality will not be difficult for clinical researchers. 展开更多
关键词 three-dimensional finite element micro-CT PREMOLAR MIMICS ANSYS
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Finite element analysis of the effect of micro-pore defect on linear friction welding of medium carbon steel 被引量:3
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作者 杨夏炜 李文亚 马铁军 《China Welding》 EI CAS 2014年第1期1-5,共5页
Micro-pore is a very common material defect. In the present paper, the temperature fields of medium carbon steel joints with and without micro-pore defect during linear friction welding (LFW) were investigated by us... Micro-pore is a very common material defect. In the present paper, the temperature fields of medium carbon steel joints with and without micro-pore defect during linear friction welding (LFW) were investigated by using finite element method. The effect of micro-pore defect on the axial shortening of joints during LFW was examined. The x- and y-direction displacements of micro-pore during the LFW process were also studied. In addition, the shape of micro-pore after LFW was observed. The heat conducted from the weld inteace to the specimen interior. The fluctuation range of the temperature curves for the joint with micro-pore is larger than that without micro-pore. Position of micro-pore changes with the change of the friction time. The circular shape of micro-pore becomes oval after welding. 展开更多
关键词 linear friction welding finite element method micro-pore temperature field
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Microanalysis of Multi-Element in Juncus effusus L. by LIBS Technique 被引量:3
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作者 刘晓娜 黄建梅 +5 位作者 吴志生 张乔 史新元 赵娜 贾帅芸 乔延江 《Plasma Science and Technology》 SCIE EI CAS CSCD 2015年第11期904-908,共5页
Laser-induced breakdown spectroscopy (LIBS) was used to decipher the unique multi-elemental characteristics of Juncus effusus L. The spectral fingerprints of Juncus effusus L. were established based on elemental mic... Laser-induced breakdown spectroscopy (LIBS) was used to decipher the unique multi-elemental characteristics of Juncus effusus L. The spectral fingerprints of Juncus effusus L. were established based on elemental microanalysis via LIBS. Microanalysis and multimode sampling methodologies were designed in this study. The relative standard deviation (RSD) approach was performed to optimize the multi-shot measurements. Taking advantage of the capability with no or minimal sample pre-treatment of LIBS, a thermodynamic chart of four elements (Mg, Ca, Ba, and Na) was created from twelve collection regions. The diagram of elemental distribution on a micro-scale was generated to explore the nature of Juncus effusus L. by LIBS. The results demon- strated that LIBS is a promising technique for rapid elemental microanalysis of heterogeneous samples. 展开更多
关键词 LIBS Juncus effusus L. RSD approach thermodynamic chart elemental microanalysis micro-SCALE
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Characterizing the influence of stress-induced microcracks on the laboratory strength and fracture development in brittle rocks using a finite-discrete element method-micro discrete fracture network FDEM-μDFN approach 被引量:6
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作者 Pooya Hamdi Doug Stead Davide Elmo 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2015年第6期609-625,共17页
Heterogeneity is an inherent component of rock and may be present in different forms including mineralheterogeneity, geometrical heterogeneity, weak grain boundaries and micro-defects. Microcracks areusually observed ... Heterogeneity is an inherent component of rock and may be present in different forms including mineralheterogeneity, geometrical heterogeneity, weak grain boundaries and micro-defects. Microcracks areusually observed in crystalline rocks in two forms: natural and stress-induced; the amount of stressinducedmicrocracking increases with depth and in-situ stress. Laboratory results indicate that thephysical properties of rocks such as strength, deformability, P-wave velocity and permeability areinfluenced by increase in microcrack intensity. In this study, the finite-discrete element method (FDEM)is used to model microcrack heterogeneity by introducing into a model sample sets of microcracks usingthe proposed micro discrete fracture network (mDFN) approach. The characteristics of the microcracksrequired to create mDFN models are obtained through image analyses of thin sections of Lac du Bonnetgranite adopted from published literature. A suite of two-dimensional laboratory tests including uniaxial,triaxial compression and Brazilian tests is simulated and the results are compared with laboratory data.The FDEM-mDFN models indicate that micro-heterogeneity has a profound influence on both the mechanicalbehavior and resultant fracture pattern. An increase in the microcrack intensity leads to areduction in the strength of the sample and changes the character of the rock strength envelope. Spallingand axial splitting dominate the failure mode at low confinement while shear failure is the dominantfailure mode at high confinement. Numerical results from simulated compression tests show thatmicrocracking reduces the cohesive component of strength alone, and the frictional strength componentremains unaffected. Results from simulated Brazilian tests show that the tensile strength is influenced bythe presence of microcracks, with a reduction in tensile strength as microcrack intensity increases. Theimportance of microcrack heterogeneity in reproducing a bi-linear or S-shape failure envelope and itseffects on the mechanisms leading to spalling damage near an underground opening are also discussed. 展开更多
关键词 Finite-discrete element method(FDEM) micro discrete fracture network(μDFN) Brittle fracture
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Recasting theory of elasticity with micro-finite elements
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作者 Wennan Zou 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2015年第5期679-684,共6页
In the classical theory of elasticity,a body is initially modeled as a homogeneous and dense assemblage of constituent "material particles".The kernel concept of elastic deformation is the displacement of the partic... In the classical theory of elasticity,a body is initially modeled as a homogeneous and dense assemblage of constituent "material particles".The kernel concept of elastic deformation is the displacement of the particle that associates the current configuration with the reference one.In this paper,we exploit an alternative constituent "micro-finite element",and use the stretch of the element as the essential quality to recast the theory of elasticity.It should be realized that such a treatment means that the elastic body can be modeled as a finite covering of elements and consequently characterized by a manifold.The recasting of the elasticity theory becomes more feasible for dealing with defects and topological evolution. 展开更多
关键词 micro-finite element STRETCH DISPLACEMENT Relative rotation Compatibility condition
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Transport patterns of micro nutrient elements from the continental shelf of the East China Sea to the Kuroshio area
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作者 Lu Saiying, Yao Qiao’er and Chen Zhen 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1992年第2期219-230,共12页
On the basis of the in situ data of DO2, pH, SiO2. PO4-P, NO3-N and NO2-N collected in the north of the East China Sea during 1987-1988, the following points are mainly expounded.1.The inorgonic nutrients are obviousl... On the basis of the in situ data of DO2, pH, SiO2. PO4-P, NO3-N and NO2-N collected in the north of the East China Sea during 1987-1988, the following points are mainly expounded.1.The inorgonic nutrients are obviously affected by continent runoff in the north of the East China Sea. Their distributions are characteristic of its distribution of terrigenous materials.2.There are three transport paths of nutrients from the shelf to the Kuroshio area. The first is mixing-diffusing-advec-tion and upwelling process, the process of biology and biochemistry belongs to the second, and the sinking process is the last one.3.The swing of the Kuroshio axis affectes both the range of the migration of substances through mixing-diffusing-advec-tion process and the upwelling degree of the subsurface Kuroshio water to the shelf.4.Most part of the substances sink as macroparticles to the deep layer before reaching the Kuroshio area. 展开更多
关键词 Transport patterns of micro nutrient elements from the continental shelf of the East China Sea to the Kuroshio area
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Biomechanical assessment of new surgical method instead of kyphoplasty to improve the mechanical behavior of the vertebra:Micro finite element study
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作者 Seyed Aref Hosseini Faradonbeh Nima Jamshidi 《World Journal of Orthopedics》 2017年第11期829-835,共7页
AIM To reduce post treatments of kyphoplasty, as a common treatment for osteoporotic vertebrae.METHODS This study suggests a new method for treating vertebrae by setting the hexagonal porous structure instead of the r... AIM To reduce post treatments of kyphoplasty, as a common treatment for osteoporotic vertebrae.METHODS This study suggests a new method for treating vertebrae by setting the hexagonal porous structure instead of the rigid bone cement mass in the kyphoplasty(KP). The KP procedure was performed on the fresh ovine vertebra of the level L1. Micro finite element modeling was performed based on micro computed tomography of ovine trabecular cube. The hexagonal porous structure was set on one cube instead of the bone cement mass. For the implant designing, two geometrical parameters were considered: Spacing diameter and thickness.RESULTS The results of micro finite element analyses indicated the improvement in the mechanical behavior of the vertebra treated by the hexagonal porous structures, as compared to those treated by vertebroplasty(VP) and KP under static loading. The improvement in the mechanical behavior of the vertebra, was observed as 54% decrease in the amount of maximum Von Misses stress(improvement of stress distribution), in trabecular cube with embedded hexagonal structure, as compared to VP and KP. This is comparable to the results of the experimental study already performed; it was shown that the improvement of mechanical behavior of the vertebra was observed as: 83% increase in the range of displacements before getting to the ultimate strength(increasing the toughness) after setting hexagonal pearls inside vertebrae. Both the material and geometry of implant influenced the amount of Von Mises stress in the structure.CONCLUSION The new proposed method can be offered as a substitute for the KP. The implant geometry had a more obvious effect on the amount of Von Mises stress, as compared to the implant material. 展开更多
关键词 VERTEBROPLASTY KYPHOPLASTY micro finite element modeling Hexagonal porous structure Von MISES stress
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Method Investigation for Fabricating Micro-Optical Elements by Use of Half Tone Masks
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作者 Tong-Kai Zhao Qin Feng 《Journal of Electronic Science and Technology》 CAS 2010年第2期131-134,共4页
Several approaches to fabricate micro optical elements by use of half tone masks are studied and compared. It is shown that half tone masks employed in filtering image systems can obtain gray patterns with considerabl... Several approaches to fabricate micro optical elements by use of half tone masks are studied and compared. It is shown that half tone masks employed in filtering image systems can obtain gray patterns with considerably high precision, but it is hard to operate from the viewpoint of operation. The method using contacting lithography technology or laser ablation can be easily operated with the cost of reducing fabrication precision and the trouble of choosing appropriate materials. For all of these methods, the coding of half tone masks with corrections for the nonlinear characteristics of coding, imaging and photoresist is recommended. 展开更多
关键词 Index Terms --Contacting lithography half tone masks micro-optical elements optical filtering systems.
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COUPLED THERMO-MECHANICAL ANALYSIS OF FUNCTIONALLY GRADIENT WEAK/MICRO-DISCONTINUOUS INTERFACE WITH GRADED FINITE ELEMENT METHOD 被引量:2
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作者 Zhiwen Gao Kang Yong Lee Youhe Zhou 《Acta Mechanica Solida Sinica》 SCIE EI 2012年第4期331-341,共11页
Coupled thermo-mechanical analysis of two bonded functionally graded materials subjected to thermal loads is conducted in this study with the graded finite element method. The thermal-mechanical properties of the bi-m... Coupled thermo-mechanical analysis of two bonded functionally graded materials subjected to thermal loads is conducted in this study with the graded finite element method. The thermal-mechanical properties of the bi-material interfaces are classified based on discontinuity degrees of their material properties and their derivatives at the interfaces. Numerical results indicate that discontinuity exerts remarkable effect on the temperature profile and stress value at the interface of two bonded functionally-graded materials. Under the thermal flux loading conditions, the stronger the interface discontinuity is, the smaller the heat flux is. 展开更多
关键词 functionally graded material thermo-mechanical analysis weak/micro discontin-uous graded finite element method
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Investigation of Micro-mechanical Response of Asphalt Mixtures by a Three-dimensional Discrete Element Model 被引量:1
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作者 侯曙光 ZHANG Dong +1 位作者 HUANG Xiaoming ZHAO Yongli 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2015年第2期338-343,共6页
The micro-mechanical response of asphalt mixtures was studied using the discrete element method. The discrete element sample of stone mastic asphalt was generated first and the vehicle load was applied to the sample. ... The micro-mechanical response of asphalt mixtures was studied using the discrete element method. The discrete element sample of stone mastic asphalt was generated first and the vehicle load was applied to the sample. A user-written program was coded with the FISH language in PFC3 D to extract the contact forces within the sample and the displacements of the particles. Then, the contact forces within the whole sample, in asphalt mastic, in coarse aggregates and between asphalt mastic and coarse aggregates were investigated. Finally, the movement of the particles in the sample was analyzed. The sample was divided into 15 areas and a figure was drawn to show how the balls move in each area according to the displacements of the balls in each area. The displacements of asphalt mastic balls and coarse aggregates were also analyzed. The experimental results explain how the asphalt mixture bears vehicle load and the potential reasons why the rutting forms from a micro-mechanical view. 展开更多
关键词 asphalt mixture discrete element method micro-mechanical response vehicle load contact force displacement
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Using Finite Element Analysis and Experimental Analysis on Vibration of a Piezoelectric Micro Pump
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作者 Bo-Wun Huang Jung-Ge Tseng +1 位作者 Chien-Hua Chang Chen-Yuan Li 《Journal of Applied Mathematics and Physics》 2015年第8期1038-1043,共6页
Due to the rise of biological and MEMS technology in recent years, some micro flow system components have drawn attention and been developed by many investigators. The importance of micro-pumps manufactured is higher ... Due to the rise of biological and MEMS technology in recent years, some micro flow system components have drawn attention and been developed by many investigators. The importance of micro-pumps manufactured is higher than the other part of micro flow system since it is the power source of the entire micro-flow system and responsible for driving working fluid in the microfluidic system. In actual operation, the instability and bad dynamic characteristics of the micro-pump will cause larger fluid flow mobility error, such as transport behavior and response procedures failure, etc., and even damage the microfluidic system. Therefore, to investigate the stability and dynamic characteristics of a micro pump is necessary. The Finite element analysis (FEA), ANSYS Workbench, is employed to analyze the dynamic characteristics of this micro pump, and experiment is also considered in this study. 展开更多
关键词 COMPONENT micro PUMP FINITE element Analysis PIEZOELECTRIC
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Micro-PIXE analysis of trace element composition and their distribution in minerals of mantle peridotite 被引量:1
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作者 陈友红 朱节清 +4 位作者 邬显慷 谷英梅 张旗 徐平 李秀云 《Nuclear Science and Techniques》 SCIE CAS CSCD 1996年第1期28-31,共4页
Micro-PIXEanalysisoftraceelementcompositionandtheirdistributionin mineralsofmantleperidotiteChenYou-Hong(陈友红... Micro-PIXEanalysisoftraceelementcompositionandtheirdistributionin mineralsofmantleperidotiteChenYou-Hong(陈友红),ZhuJie-Qing(朱节清... 展开更多
关键词 地质学 示踪元素组成 地幔橄榄岩矿石 分布
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micro-CT和有限元分析技术在手舟骨研究中的应用进展
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作者 吕远 张德洲 +11 位作者 钱海龙 王思敏 王超群 李琨 陈杰 白雪 赵海龙 张少杰 马渊 李志军 史君 王星 《局解手术学杂志》 2025年第2期168-173,共6页
手舟骨是手部的重要骨骼之一,在临床上损伤频发且治疗具有一定难度。因此,深入研究手舟骨的微观结构和生物力学特征对了解其损伤机制和优化治疗方案至关重要。微计算机断层扫描(micro-CT)技术提供了高分辨率的骨组织成像,而有限元分析... 手舟骨是手部的重要骨骼之一,在临床上损伤频发且治疗具有一定难度。因此,深入研究手舟骨的微观结构和生物力学特征对了解其损伤机制和优化治疗方案至关重要。微计算机断层扫描(micro-CT)技术提供了高分辨率的骨组织成像,而有限元分析则能帮助模拟手舟骨在不同生理和病理状态下的应力分布和行为模式。通过micro-CT技术获取手舟骨的高分辨率三维图像,能够用于构建手舟骨真实解剖结构的有限元模型,从而实现对手舟骨力学性能的精确模拟。这两种先进技术的融合为揭示手舟骨的结构功能关系及其损伤机制提供了新视角。因此,本文回顾了手舟骨的解剖学特征及其在不同状态下的生物力学行为,并重点讨论了micro-CT和有限元分析技术在手舟骨研究中的具体应用及其优势,通过综述近几年来的研究成果,为手舟骨相关疾病的诊断、治疗及预防提供新的科学依据和方法。 展开更多
关键词 手舟骨 微观结构 生物力学 micro-CT 有限元分析 基础研究 临床研究 研究进展
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Analysis and Design of Thermally Actuated Micro-Cantilevers for High Frequency Vibrations Using Finite Element Method
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作者 Mojtaba Komeili Carlo Menon 《World Journal of Mechanics》 2016年第3期94-107,共14页
Vibrational behavior of thermally actuated cantilever micro-beams and their mechanical response at moderately high frequency under a non-harmonic periodic loading is studied in this paper. Two different configurations... Vibrational behavior of thermally actuated cantilever micro-beams and their mechanical response at moderately high frequency under a non-harmonic periodic loading is studied in this paper. Two different configurations are considered: 1) a straight beam with two actuation layers on top and bottom which utilizes the bimorph effect to induce bending;2) a uniform beam with base excitation, where the beam is mounted on an actuator which moves it periodically at its base perpendicular to its axis. Generally, vibrating micro-cantilevers are required to oscillate at a specified frequency. In order to increase the efficiency of the system, and achieve deflections with low power consumption, geometrical features of the beams can be quantified so that the required vibrating frequency matches the natural frequencies of the beam. A parametric modal analysis is conducted on two configurations of micro-cantilever and the first natural frequency of the cantilevers as a function of geometrical parameters is extracted. To evaluate vibrational behavior and thermo-mechanical efficiency of micro-cantilevers as a function of their geometrical parameters and input power, a case study with a specified vibrating frequency is considered. Due to significant complexities in the loading conditions and thermo-mechanical behavior, this task can only be tackled via numerical methods. Selecting the geometrical parameters in order to induce resonance at the nominal frequency, non-linear time-history (transient) thermo-mechanical finite element analysis (using ANSYS) is run on each configuration to study its response to the periodic heating input. Approaches to improve the effectiveness of actuators in each configuration based on their implementation are investigated. 展开更多
关键词 micro-Electro-Mechanical Systems Finite element Thermal Actuations micro-CANTILEVER Dynamic Thermo-Mechanical Analysis
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饰品用银基合金的成分设计与抗变色性能研究
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作者 郭威 吴健乔 +3 位作者 李龙丰 刘波 吴锟钰 吴树森 《铸造》 2026年第2期168-173,共6页
针对饰品用银基合金易变色的问题,通过添加贵金属元素铂(Pt),设计并制备了新型抗变色银基合金,系统研究了Pt含量(质量分数)对合金微观组织、力学性能及抗变色能力的影响。结果表明:随着Pt含量的升高,银合金中黑色Si、C富集相减少,富Pt... 针对饰品用银基合金易变色的问题,通过添加贵金属元素铂(Pt),设计并制备了新型抗变色银基合金,系统研究了Pt含量(质量分数)对合金微观组织、力学性能及抗变色能力的影响。结果表明:随着Pt含量的升高,银合金中黑色Si、C富集相减少,富Pt相开始析出并逐渐增多。合金硬度随着Pt含量升高先升高后降低。Pt元素能够抑制腐蚀介质对银基体的侵蚀,显著提升银合金的抗变色性能。当Pt含量为2%时,合金RGB平均值达195.8,硬度为HV85.9,抗变色能力最优,但进一步增加Pt时抗变色效果提升不明显。 展开更多
关键词 银基合金 微元素添加 合金化 抗变色能力
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W型金属封严环的磨损寿命可靠性研究
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作者 何建军 肖庭熠 +3 位作者 刘豪 龚志辉 杨迪 白郑言 《兵器材料科学与工程》 北大核心 2026年第1期135-143,共9页
航空发动机金属封严环的磨损会造成发动机内部气流泄漏,影响发动机的运行效率和性能。研究实际工况下封严环的磨损机理、力学性能、磨损寿命对解决封严环的磨损失效问题具有重要意义。本文以航空发动机W型金属封严环为研究对象采用有限... 航空发动机金属封严环的磨损会造成发动机内部气流泄漏,影响发动机的运行效率和性能。研究实际工况下封严环的磨损机理、力学性能、磨损寿命对解决封严环的磨损失效问题具有重要意义。本文以航空发动机W型金属封严环为研究对象采用有限元分析方法分析了位移幅值和循环次数与封严环磨损之间的非线性关系,研究了其在服役过程中的磨损以及寿命可靠性分布。结果表明:在可靠度低于90%时不同位移幅值的磨损失效深度平均值为0.023 4 mm,与封严环的最大允许磨损深度设计准则对比误差为6.3%。研究表明,本文所建立的磨损寿命可靠性模型可较准确地评估封严环磨损情况。 展开更多
关键词 W型金属封严环 微动磨损 磨损寿命 有限元
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微合金化元素La对经Al-5Ti-1B处理的Al-Mg合金凝固组织影响
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作者 李赐宇 张丽丽 +3 位作者 张悦 江鸿翔 赵九洲 何杰 《物理学报》 北大核心 2026年第1期420-427,共8页
实验研究了微合金化元素La对经Al-5Ti-1B细化处理的Al-Mg合金凝固组织的影响,发现添加微量的La可进一步细化Al-Mg合金凝固组织,降低a-Al的形核过冷度.建立了微合金化元素La在Al合金熔体和TiB_(2)界面处偏析行为模型,探明了微合金化元素L... 实验研究了微合金化元素La对经Al-5Ti-1B细化处理的Al-Mg合金凝固组织的影响,发现添加微量的La可进一步细化Al-Mg合金凝固组织,降低a-Al的形核过冷度.建立了微合金化元素La在Al合金熔体和TiB_(2)界面处偏析行为模型,探明了微合金化元素La增强TiB_(2)粒子对a-Al异质形核能力的作用机理,计算结果表明,微合金化元素La富集于Al熔体和TiB_(2)粒子间界面处,降低TiB_(2)和a-Al间的界面能和接触角,增强TiB_(2)对a-Al的形核能力,进一步细化基体晶粒组织. 展开更多
关键词 AL-MG合金 晶粒细化 微合金化元素La Al-5Ti-B
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窄脉冲铒激光对牙本质微裂纹的理论与实验研究
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作者 张跃云 黄磊 +1 位作者 程庭清 江海河 《应用激光》 北大核心 2026年第1期185-192,共8页
旨在研究窄脉冲铒激光对牙本质微裂纹的影响,通过理论与实验相结合的方法,探讨激光烧蚀牙本质过程中的热相互作用原理及其产生的热应力。研究通过回顾激光治疗在口腔医学中的应用历史,指出现有激光系统在治疗过程中可能引起的牙本质微... 旨在研究窄脉冲铒激光对牙本质微裂纹的影响,通过理论与实验相结合的方法,探讨激光烧蚀牙本质过程中的热相互作用原理及其产生的热应力。研究通过回顾激光治疗在口腔医学中的应用历史,指出现有激光系统在治疗过程中可能引起的牙本质微裂纹问题。通过相关前期研究,建立基于COMSOL软件的激光烧蚀牙本质的有限元仿真模型。通过与实际激光烧蚀实验数据的对比,验证了仿真模型的准确性。选取激光脉宽100ns与100μs,光斑半径为0.4 mm,激光脉冲频率为20 Hz,辐照时间为12s,单脉冲能量均为15 mJ,对比不同脉宽铒激光烧蚀下的牙本质热致应力变化情况。研究结果显示,100ns脉冲激光烧蚀在牙本质中的Von Mises应力最大值远低于牙本质的断裂应力,能有效减少治疗过程中微裂纹的产生和扩张。这一发现为纳秒脉冲激光在牙科临床应用中提供了理论依据,有助于优化激光参数,降低治疗过程中的并发症风险。 展开更多
关键词 窄脉冲激光 微裂纹 有限元仿真 烧蚀温度
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轻水反应堆环境对不锈钢辐照促进应力腐蚀开裂的影响综述
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作者 徐超亮 全琪炜 +8 位作者 武焕春 李远飞 贾文清 尹建 李时磊 宋淼 张乐福 刘向兵 郭相龙 《材料导报》 北大核心 2026年第1期138-148,共11页
轻水反应堆(LWR)堆内构件等不锈钢材料服役在高温、强辐照和反应堆一回路水耦合环境下,辐照促进应力腐蚀开裂(IASCC)是其最主要的失效机制,导致了核工业界多起堆内构件部件的断裂事件。本文通过调研分析,介绍了LWR中的辐照环境,分析了LW... 轻水反应堆(LWR)堆内构件等不锈钢材料服役在高温、强辐照和反应堆一回路水耦合环境下,辐照促进应力腐蚀开裂(IASCC)是其最主要的失效机制,导致了核工业界多起堆内构件部件的断裂事件。本文通过调研分析,介绍了LWR中的辐照环境,分析了LWR环境中辐照对不锈钢微观结构与硬度、微区化学元素、一回路水电化学腐蚀电位(ECP)、温度和应力的影响,继而总结了上述影响因素对IASCC的影响规律。 展开更多
关键词 轻水反应堆 辐照促进应力腐蚀开裂 辐照硬化 微结构演变 微区化学元素偏析 电化学腐蚀电位 应力
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