资源类型

期刊论文 129

会议视频 2

年份

2023 12

2022 6

2021 8

2020 2

2019 3

2018 6

2017 13

2016 15

2015 4

2014 4

2013 6

2012 5

2011 3

2010 7

2009 3

2008 5

2007 11

2006 3

2005 1

2004 3

展开 ︾

关键词

原子力显微镜 4

发展战略 4

技术预见 3

力常数 2

对策建议 2

战略研究 2

波浪力 2

海洋工程 2

混凝土 2

键能 2

键长 2

2035年 1

360°表征 1

Casimir力 1

FE-SEA混合法 1

Lorentz 1

PPWS 1

三星一线 1

三点弯曲梁 1

展开 ︾

检索范围：

排序： 展示方式：

Meshing stiffness property and meshing status simulation of harmonic drive under transmission loading

《机械工程前沿（英文）》 2022年 第17卷 第2期 doi: 10.1007/s11465-022-0674-6

摘要： The multitooth meshing state of harmonic drive (HD) is an important basic characteristic of its high transformation precision and high bearing capacity. Meshing force distribution affects the load sharing of the tooth during meshing, and theoretical research remains insufficient at present. To calculate the spatial distributed meshing forces and loading backlashes along the axial direction, an iterative algorithm and finite element model (FEM) is proposed to investigate the meshing state under varied transmission loading. The displacement formulae of meshing point under tangential force are derived according to the torsion of the flexspline cylinder and the bending of the tooth. Based on the relationship of meshing forces and circumferential displacements, meshing forces and loading backlashes in three cross-sections are calculated with the algorithm under gradually increased rotation angles of circular spline, and the results are compared with FEM. Owing to the taper deformation of the cup-shaped flexspline, the smallest initial backlash and the earliest meshing point appear in the front cross-section far from the cup bottom, and then the teeth in the middle cross-section of the tooth rim enter the meshing and carry most of the loading. Theoretical and numerical research show that the flexibility is quite different for varied meshing points and tangential force amplitude because of the change of contact status between the flexspline and the wave generator. The meshing forces and torsional stiffness of the HD are nonlinear with the torsional angle.

关键词： harmonic drive     meshing flexibility matrix     meshing force     loading backlash     flexspline     contact analysis    

HTML PDF 收藏

Gear fault diagnosis using gear meshing stiffness identified by gearbox housing vibration signals

《机械工程前沿（英文）》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0713-3

摘要： Gearbox fault diagnosis based on vibration sensing has drawn much attention for a long time. For highly integrated complicated mechanical systems, the intercoupling of structure transfer paths results in a great reduction or even change of signal characteristics during the process of original vibration transmission. Therefore, using gearbox housing vibration signal to identify gear meshing excitation signal is of great significance to eliminate the influence of structure transfer paths, but accompanied by huge scientific challenges. This paper establishes an analytical mathematical description of the whole transfer process from gear meshing excitation to housing vibration. The gear meshing stiffness (GMS) identification approach is proposed by using housing vibration signals for two stages of inversion based on the mathematical description. Specifically, the linear system equations of transfer path analysis are first inverted to identify the bearing dynamic forces. Then the dynamic differential equations are inverted to identify the GMS. Numerical simulation and experimental results demonstrate the proposed method can realize gear fault diagnosis better than the original housing vibration signal and has the potential to be generalized to other speeds and loads. Some interesting properties are discovered in the identified GMS spectra, and the results also validate the rationality of using meshing stiffness to describe the actual gear meshing process. The identified GMS has a clear physical meaning and is thus very useful for fault diagnosis of the complicated equipment.

关键词： gearbox fault diagnosis     meshing stiffness     identification     transfer path     signal processing    

HTML PDF 收藏

基于层次优化的图像网格化方法

Hao XIE,Ruo-feng TONG

《信息与电子工程前沿（英文）》 2016年 第17卷 第1期   页码 32-40 doi: 10.1631/FITEE.1500171

摘要：

矢量图形作为光栅图像的一种几何表示形式，具有许多优点，例如，定义独立性和编辑功能。将栅格图像转换为矢量图形的一种流行方法是图像网格划分，其目的是找到一个网格以尽可能忠实地表示图像。对于传统的网格划分算法，问题的症结主要在于目标的高非线性度和非平滑度，这使得很难找到理想的最优解。为了改善这种情况，我们提出了一种层次优化算法，解决了从较粗级别到较细级别的问题，并为每个级别提供了其较粗的提升的初始化功能。为了进一步简化问题，将原始的非凸问题转换为线性最小二乘，从而变成凸的，这使问题更容易解决。字典学习框架用于将几何和拓扑完美地结合在一起。然后采用交替方案来求解两个部分。实验表明，对于大多数图像，该算法运行速度快，效果优于现有图像。

关键词： 图像网格化；层次优化；凸化    

HTML PDF 收藏

Effects of Boundary Condition and Helix Angle on Meshing Performance of TI Worm Gearing

SUN Yue-hai, DUAN Lu-qian, WANG Shu-ren, ZHANG Ce

《机械工程前沿（英文）》 2006年 第1卷 第1期   页码 90-95 doi: 10.1007/s11465-005-0006-7

摘要：

To exactly describe the contact state and contact area of tooth surface of toroidal involute (TI) worm gearing, the authors introduced boundary condition into contact line analysis.With helix angle chosen as parameter, the criterion for the existence of meshing boundary line on the surface of TI worm gearing is derived. Results show that there can be four situations for meshing boundary line on the tooth surface of gear, namely, inexistence of meshing boundary line, a unique line, two lines, and two coincident lines. If the helix angle is equal to or slightly smaller than the bigger angle, which makes two meshing boundary lines superpose, a preferable meshing performance is obtained. Computer simulation proves the validity of the above conclusion.

关键词： preferable     inexistence     Results     validity     boundary condition    

HTML PDF 收藏

Modeling limit force capacities of high force to volume lead extrusion dampers

《结构与土木工程前沿（英文）》 2021年 第15卷 第3期   页码 609-622 doi: 10.1007/s11709-021-0724-x

摘要： Lead extrusion dampers are supplemental energy-dissipation devices that are used to mitigate seismic structural damage. Small volumetric sizes and high force capacities define high-force-to-volume (HF2V) devices, which can absorb significant response energy without sacrificial damage. However, the design of such devices for specific force capacities has proven difficult based on the complexities of their internal reaction mechanisms, leading to the adoption of empirical approaches. This study developed upper- and lower-bound force capacity estimates from analytical mechanics based on direct and indirect metal extrusion for guiding design. The derived equations are strictly functions of HF2V device geometric parameters, lead material properties, and extrusion mechanics. The upper-bound estimates from direct and indirect extrusion are denoted as (FUB,1, FUB,2) and (FUB,3, FUB,4), respectively, and the lower-bound estimates are denoted as (FLB, FLB,1) based on the combination of extrusion and friction forces. The proposed models were validated by comparing the predicted bounds to experimental force capacity data from 15 experimental HF2V device tests. The experimental device forces all lie above the lower-bound estimates (FLB, FLB,1) and below the upper-bound estimates (FUB,1, FUB,2, FUB,4). Overall, the (FLB, FUB,2) pair provides wider bounds and the (FLB,1, FUB,4/FUB,1) pair provides narrower bounds. The (FLB,1, FUB,1) pair has a mean lower-bound gap of 36%, meaning the lower bound was 74% of the actual device force on average. The mean upper-bound gap was 33%. The bulge area and cylinder diameter of HF2V devices are key parameters affecting device forces. These relatively tight bounds provide useful mechanics-based predictive design guides for ensuring that device forces are within the targeted design range after manufacturing.

关键词： extrusion     lead dampers     upper and lower bound     analytical modelling     limit force    

HTML PDF 收藏

Quality control based on electrode displacement and force in resistance spot welding

Chuntao JI, Lipeng DENG

《机械工程前沿（英文）》 2010年 第5卷 第4期   页码 412-417 doi: 10.1007/s11465-010-0114-x

摘要： The behaviors of electrode displacement and force during spot welding under various conditions, such as different weld currents, electrode forces, and welding times, were studied. Tests were conducted on a 170?kVA MFDC spot welder. Data were collected via a multichannel high-speed data acquisition system and were analyzed with MATLAB. Behaviors of 5182 aluminum and mild steel in spot welding were compared. Results show that nugget expansion rate does not reach zero for aluminium as it does for mild steel as nugget grew to a certain size. A linear relationship is found between the nugget size and maximum expansion that facilitates online weld quality evaluation. An electrode force peak is observed and believed relevant to the sufficient nugget size.

关键词： aluminum     electrode displacement     electrode force     nugget size     data acquisition    

HTML PDF 收藏

Visualization of force networks in 2D dense granular materials

Jianguo LIU, Qicheng SUN, Feng JIN,

《结构与土木工程前沿（英文）》 2010年 第4卷 第1期   页码 109-115 doi: 10.1007/s11709-010-0003-8

摘要： Dense granular matter is a conglomeration of discrete solid and closely packed particles. As subjected to external loadings, the stress is largely transmitted by heavily stressed chains of particles forming a sparse network of larger contact forces. To understand the structure and evolution of force chains, a photoelastic technique was improved for determining stresses and strains in the assemblies of photoelastic granular disks in this paper. A two-dimensional vertical slab was designed. It contains 7200 polydispersed photoelastic disks and is subjected to a localized probe penetrating at the top of the slab to mimic the cone penetration test. The interparticle contact force distribution was found a peak around the mean value, a roughly exponential tail for greater force and a dip toward zero for smaller force. The force chain network around the probe tip was depicted, and the contact angle distribution of particles in force chains was found to be well aligned in the directions of major principal stress.

关键词： granular matter     force chain     multiscale modeling    

HTML PDF 收藏

Motion/force transmission indices of parallel manipulators

Xinjun LIU, Chao WU, Fugui XIE

《机械工程前沿（英文）》 2011年 第6卷 第1期   页码 89-91 doi: 10.1007/s11465-011-0215-1

HTML PDF 收藏

Applications of atomic force microscopy in immunology

Jiping Li, Yuying Liu, Yidong Yuan, Bo Huang

《医学前沿（英文）》 2021年 第15卷 第1期   页码 43-52 doi: 10.1007/s11684-020-0769-6

摘要： Cellular mechanics, a major regulating factor of cellular architecture and biological functions, responds to intrinsic stresses and extrinsic forces exerted by other cells and the extracellular matrix in the microenvironment. Cellular mechanics also acts as a fundamental mediator in complicated immune responses, such as cell migration, immune cell activation, and pathogen clearance. The principle of atomic force microscopy (AFM) and its three running modes are introduced for the mechanical characterization of living cells. The peak force tapping mode provides the most delicate and desirable virtues to collect high-resolution images of morphology and force curves. For a concrete description of AFM capabilities, three AFM applications are discussed. These applications include the dynamic progress of a neutrophil-extracellular-trap release by neutrophils, the immunological functions of macrophages, and the membrane pore formation mediated by perforin, streptolysin O, gasdermin D, or membrane attack complex.

关键词： cellular mechanics     atomic force microscopy     neutrophil extracellular trap     macrophage phagocytosis     pore formation    

HTML PDF 收藏

Non-convex sparse optimization-based impact force identification with limited vibration measurements

《机械工程前沿（英文）》 2023年 第18卷 第3期 doi: 10.1007/s11465-023-0762-2

摘要： Impact force identification is important for structure health monitoring especially in applications involving composite structures. Different from the traditional direct measurement method, the impact force identification technique is more cost effective and feasible because it only requires a few sensors to capture the system response and infer the information about the applied forces. This technique enables the acquisition of impact locations and time histories of forces, aiding in the rapid assessment of potentially damaged areas and the extent of the damage. As a typical inverse problem, impact force reconstruction and localization is a challenging task, which has led to the development of numerous methods aimed at obtaining stable solutions. The classical ℓ2 regularization method often struggles to generate sparse solutions. When solving the under-determined problem, ℓ2 regularization often identifies false forces in non-loaded regions, interfering with the accurate identification of the true impact locations. The popular ℓ1 sparse regularization, while promoting sparsity, underestimates the amplitude of impact forces, resulting in biased estimations. To alleviate such limitations, a novel non-convex sparse regularization method that uses the non-convex ℓ1−2 penalty, which is the difference of the ℓ1 and ℓ2 norms, as a regularizer, is proposed in this paper. The principle of alternating direction method of multipliers (ADMM) is introduced to tackle the non-convex model by facilitating the decomposition of the complex original problem into easily solvable subproblems. The proposed method named ℓ1−2-ADMM is applied to solve the impact force identification problem with unknown force locations, which can realize simultaneous impact localization and time history reconstruction with an under-determined, sparse sensor configuration. Simulations and experiments are performed on a composite plate to verify the identification accuracy and robustness with respect to the noise of the ℓ1−2-ADMM method. Results indicate that compared with other existing regularization methods, the ℓ1−2-ADMM method can simultaneously reconstruct and localize impact forces more accurately, facilitating sparser solutions, and yielding more accurate results.

关键词： impact force identification     inverse problem     sparse regularization     under-determined condition     alternating direction method of multipliers    

HTML PDF 收藏

Shape and topology optimization for tailoring the ratio between two flexural eigenfrequencies of atomic force

Qi XIA,Tao ZHOU,Michael Yu WANG,Tielin SHI

《机械工程前沿（英文）》 2014年 第9卷 第1期   页码 50-57 doi: 10.1007/s11465-014-0286-x

摘要：

In an operation mode of atomic force microscopy that uses a higher eigenmode to determine the physical properties of material surface, the ratio between the eigenfrequency of a higher flexural eigenmode and that of the first flexural eigenmode was identified as an important parameter that affects the sensitivity and accessibility. Structure features such as cut-out are often used to tune the ratio of eigenfrequencies and to enhance the performance. However, there lacks a systematic and automatic method for tailoring the ratio. In order to deal with this issue, a shape and topology optimization problem is formulated, where the ratio between two eigenfrequencies is defined as a constraint and the area of the cantilever is maximized. The optimization problem is solved via the level set based method.

关键词： atomic force microscopy     cantilever probe     eigenfrequency     optimization    

HTML PDF 收藏

on PVDF ultrafiltration membrane fouling behavior under different pH conditions: interface adhesion force

Xudong WANG,Miao ZHOU,Xiaorong MENG,Lei WANG,Danxi HUANG

《环境科学与工程前沿（英文）》 2016年 第10卷 第4期 doi: 10.1007/s11783-016-0855-9

摘要： pH values of the BSA solution significantly impact the process of membrane fouling. Dramatic flux decline is caused by membrane–BSA adhesion force at start of filtration. XDLVO theory shows the polar or Lewis acid–base interaction plays a major role in membrane fouling. To further determine the fouling behavior of bovine serum albumin (BSA) on different hydrophilic PVDF ultrafiltration (UF) membranes over a range of pH values, self-made atomic force microscopy (AFM) colloidal probes were used to detect the adhesion forces of membrane–BSA and BSA–BSA, respectively. Results showed that the membrane–BSA adhesion interaction was stronger than the BSA–BSA adhesion interaction, and the adhesion force between BSA–BSA-fouled PVDF/PVA membranes was similar to that between BSA–BSA-fouled PVDF/PVP membranes, which indicated that the fouling was mainly caused by the adhesion interaction between membrane and BSA. At the same pH condition, the PVDF/PVA membrane–BSA adhesion force was smaller than that of PVDF/PVP membrane–BSA, which illustrated that the more hydrophilic the membrane was, the better antifouling ability it had. The extended Derjaguin–Landau–Verwey–Overbeek (XDLVO) theory predicts that the polar or Lewis acid–base (AB) interaction played a dominant role in the interfacial free energy of membrane–BSA and BSA–BSA that can be affected by pH. For the same membrane, the pH values of a BSA solution can have a significant impact on the process of membrane fouling by changing the AB component of free energy.

关键词： PVDF membrane     Membrane fouling     Adhesion force     Protein     Interfacial free energy    

HTML PDF 收藏

Nonlinear sealing force of a seawater balance valve used in an 11000-meter manned submersible

《机械工程前沿（英文）》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0726-y

摘要： Balance valve is a core component of the 11000-meter manned submersible “struggle,” and its sealing performance is crucial and challenging when the maximum pressure difference is 118 MPa. The increasing sealing force improves the sealing performance and increases the system’s energy consumption at the same time. A hybrid analytical–numerical–experimental (ANE) model is proposed to obtain the minimum sealing force, ensuring no leakage at the valve port and reducing energy consumption as much as possible. The effects of roundness error, environmental pressure, and materials on the minimum sealing force are considered in the ANE model. The basic form of minimum sealing force equations is established, and the remaining unknown coefficients of the equations are obtained by the finite element method (FEM). The accuracy of the equation is evaluated by comparing the independent FEM data to the equation data. Results of the comparison show good agreement, and the difference between the independent FEM data and equation data is within 3% when the environmental pressure is 0–118 MPa. Finally, the minimum sealing force equation is applied in a balance valve to be experimented using a deep-sea simulation device. The balance valve designed through the minimum sealing force equation is leak-free in the experiment. Thus, the minimum sealing force equation is suitable for the ultrahigh pressure balance valve and has guiding significance for evaluating the sealing performance of ultrahigh pressure balance valves.

关键词： seawater balance valve     sealing performance     hybrid ANE model     FEM     minimum sealing force equation    

HTML PDF 收藏

bionic approach for the mechanical and electrical decoupling of an MEMS capacitive sensor in ultralow force

《机械工程前沿（英文）》 2023年 第18卷 第2期 doi: 10.1007/s11465-023-0747-1

摘要： Capacitive sensors are efficient tools for biophysical force measurement, which is essential for the exploration of cellular behavior. However, attention has been rarely given on the influences of external mechanical and internal electrical interferences on capacitive sensors. In this work, a bionic swallow structure design norm was developed for mechanical decoupling, and the influences of structural parameters on mechanical behavior were fully analyzed and optimized. A bionic feather comb distribution strategy and a portable readout circuit were proposed for eliminating electrostatic interferences. Electrostatic instability was evaluated, and electrostatic decoupling performance was verified on the basis of a novel measurement method utilizing four complementary comb arrays and application-specific integrated circuit readouts. An electrostatic pulling experiment showed that the bionic swallow structure hardly moved by 0.770 nm, and the measurement error was less than 0.009% for the area-variant sensor and 1.118% for the gap-variant sensor, which can be easily compensated in readouts. The proposed sensor also exhibited high resistance against electrostatic rotation, and the resulting measurement error dropped below 0.751%. The rotation interferences were less than 0.330 nm and (1.829 × 10−7)°, which were 35 times smaller than those of the traditional differential one. Based on the proposed bionic decoupling method, the fabricated sensor exhibited overwhelming capacitive sensitivity values of 7.078 and 1.473 pF/µm for gap-variant and area-variant devices, respectively, which were the highest among the current devices. High immunity to mechanical disturbances was maintained simultaneously, i.e., less than 0.369% and 0.058% of the sensor outputs for the gap-variant and area-variant devices, respectively, indicating its great performance improvements over existing devices and feasibility in ultralow biomedical force measurement.

关键词： micro-electro-mechanical system capacitive sensor     bionics     operation instability     mechanical and electrical decoupling     biomedical force measurement    

HTML PDF 收藏

Reverse engineering in the construction of numerical simulation oriented patient-specific model of stented aortic arch aneurysm

Xianlong MENG, Wenyu FU, Yun ZHANG, Aike QIAO,

《机械工程前沿（英文）》 2010年 第5卷 第3期   页码 328-335 doi: 10.1007/s11465-010-0026-9

摘要： Patient-specific models are widely used in hemodynamic simulations. The flow in the boundary layer changes so strongly that fine meshes in the boundary layer are required in numerical simulations, especially for the calculation of wall shear stress and its gradient. To precisely analyze hemodynamics, it is necessary to investigate the approaches to the reconstruction of a numerical simulation-oriented patient-specific model for aortic arch aneurysm that can perform particular meshing in the boundary layer. Based on a surface model of aortic arch aneurysm in STL format, reverse engineering concept was applied to reconstruct a solid model using CAD software Geomagic and Pro/E, and a simplified model of stent for the intervention of aortic arch aneurysm was also created. After these models were imported to ANSYS, a block modeling approach was employed to divide the whole model into several domain blocks to adopt different meshing strategies. Particular meshing was performed especially in the boundary layer and around the stents. The finite element model particularly suitable for numerical simulation of hemodynamics was obtained. Hemodynamic simulation was performed, using the constructed finite element model to verify its applicability. The results indicate that reverse engineering concept and the proposed block modeling approach can be used to divide the solid model of aortic arch aneurysm into multiple volumes, which can be meshed according to particular requirements in each volume; the finite element model of stented aortic arch aneurysm can be employed to simulate hemodynamics. The approaches of modeling were applicable not only for aortic arch aneurysm, but also for similar model reconstruction as a reference in hemodynamic simulation investigations.

关键词： reverse engineering     aortic arch aneurysm     surface model     meshing     finite element model    

HTML PDF 收藏

标题 作者 时间 类型 操作

Meshing stiffness property and meshing status simulation of harmonic drive under transmission loading

期刊论文

Gear fault diagnosis using gear meshing stiffness identified by gearbox housing vibration signals

期刊论文

基于层次优化的图像网格化方法

Hao XIE,Ruo-feng TONG

期刊论文

Effects of Boundary Condition and Helix Angle on Meshing Performance of TI Worm Gearing

SUN Yue-hai, DUAN Lu-qian, WANG Shu-ren, ZHANG Ce

期刊论文

Modeling limit force capacities of high force to volume lead extrusion dampers

期刊论文

Quality control based on electrode displacement and force in resistance spot welding

Chuntao JI, Lipeng DENG

期刊论文

Visualization of force networks in 2D dense granular materials

Jianguo LIU, Qicheng SUN, Feng JIN,

期刊论文

Motion/force transmission indices of parallel manipulators

Xinjun LIU, Chao WU, Fugui XIE

期刊论文

Applications of atomic force microscopy in immunology

Jiping Li, Yuying Liu, Yidong Yuan, Bo Huang

期刊论文

Non-convex sparse optimization-based impact force identification with limited vibration measurements

期刊论文

Shape and topology optimization for tailoring the ratio between two flexural eigenfrequencies of atomic force

Qi XIA,Tao ZHOU,Michael Yu WANG,Tielin SHI

期刊论文

on PVDF ultrafiltration membrane fouling behavior under different pH conditions: interface adhesion force

Xudong WANG,Miao ZHOU,Xiaorong MENG,Lei WANG,Danxi HUANG

期刊论文

Nonlinear sealing force of a seawater balance valve used in an 11000-meter manned submersible

期刊论文

bionic approach for the mechanical and electrical decoupling of an MEMS capacitive sensor in ultralow force

期刊论文

Reverse engineering in the construction of numerical simulation oriented patient-specific model of stented aortic arch aneurysm

Xianlong MENG, Wenyu FU, Yun ZHANG, Aike QIAO,

期刊论文