资源类型

期刊论文 715

年份

2023 54

2022 50

2021 52

2020 51

2019 52

2018 39

2017 40

2016 28

2015 30

2014 26

2013 29

2012 21

2011 28

2010 39

2009 26

2008 26

2007 32

2006 17

2005 18

2004 8

展开 ︾

关键词

动力特性 6

动态规划 5

增材制造 4

建模 4

人工智能 3

动力响应 3

动力学 3

深度学习 3

SWAT模型 2

代理模型 2

力学性能 2

动力气垫 2

动态 2

动态特性 2

动态管理 2

建模仿真 2

扬矿管 2

数值模拟 2

机器学习 2

展开 ︾

检索范围：

排序： 展示方式：

PRESS-based EFOR algorithm for the dynamic parametrical modeling of nonlinear MDOF systems

Haopeng LIU, Yunpeng ZHU, Zhong LUO, Qingkai HAN

《机械工程前沿（英文）》 2018年 第13卷 第3期   页码 390-400 doi: 10.1007/s11465-017-0459-5

摘要：

In response to the identification problem concerning multi-degree of freedom (MDOF) nonlinear systems, this study presents the extended forward orthogonal regression (EFOR) based on predicted residual sums of squares (PRESS) to construct a nonlinear dynamic parametrical model. The proposed parametrical model is based on the non-linear autoregressive with exogenous inputs (NARX) model and aims to explicitly reveal the physical design parameters of the system. The PRESS-based EFOR algorithm is proposed to identify such a model for MDOF systems. By using the algorithm, we built a common-structured model based on the fundamental concept of evaluating its generalization capability through cross-validation. The resulting model aims to prevent over-fitting with poor generalization performance caused by the average error reduction ratio (AERR)-based EFOR algorithm. Then, a functional relationship is established between the coefficients of the terms and the design parameters of the unified model. Moreover, a 5-DOF nonlinear system is taken as a case to illustrate the modeling of the proposed algorithm. Finally, a dynamic parametrical model of a cantilever beam is constructed from experimental data. Results indicate that the dynamic parametrical model of nonlinear systems, which depends on the PRESS-based EFOR, can accurately predict the output response, thus providing a theoretical basis for the optimal design of modeling methods for MDOF nonlinear systems.

关键词： MDOF     dynamic parametrical model     NARX model     PRESS-based EFOR     cantilever beam    

HTML PDF 收藏

Mesh relationship modeling and dynamic characteristic analysis of external spur gears with gear wear

《机械工程前沿（英文）》 2022年 第17卷 第1期   页码 9-9 doi: 10.1007/s11465-021-0665-z

摘要： Gear wear is one of the most common gear failures, which changes the mesh relationship of normal gear. A new mesh relationship caused by gear wear affects meshing excitations, such as mesh stiffness and transmission error, and further increases vibration and noise level. This paper aims to establish the model of mesh relationship and reveal the vibration characteristics of external spur gears with gear wear. A geometric model for a new mesh relationship with gear wear is proposed, which is utilized to evaluate the influence of gear wear on mesh stiffness and unloaded static transmission error (USTE). Based on the mesh stiffness and USTE considering gear wear, a gear dynamic model is established, and the vibration characteristics of gear wear are numerically studied. Comparison with the experimental results verifies the proposed dynamic model based on the new mesh relationship. The numerical and experimental results indicate that gear wear does not change the structure of the spectrum, but it alters the amplitude of the meshing frequencies and their sidebands. Several condition indicators, such as root-mean-square, kurtosis, and first-order meshing frequency amplitude, can be regarded as important bases for judging gear wear state.

关键词： gear wear     mesh relationship     mesh stiffness     transmission error     vibration characteristics    

HTML PDF 收藏

Special issue: Wind turbine dynamic modeling, condition monitoring and diagnosis

Zheng YOU, Jinji GAO, Fulei CHU, Tielin SHI

《机械工程前沿（英文）》 2017年 第12卷 第3期   页码 279-280 doi: 10.1007/s11465-017-0476-4

HTML PDF 收藏

Dynamic modeling of hydrostatic guideway considering compressibility and inertia effect

Yikang DU,Kuanmin MAO,Yaming ZHU,Fengyun WANG,Xiaobo MAO,Bin LI

《机械工程前沿（英文）》 2015年 第10卷 第1期   页码 78-88 doi: 10.1007/s11465-015-0331-4

摘要：

Hydrostatic guideways are used as an alternative to contact bearings due to high stiffness and high damping in heavy machine tools. To improve the dynamic characteristic of bearing structure, the dynamic modeling of the hydrostatic guidway should be accurately known. This paper presents a “mass-spring-Maxwell” model considering the effects of inertia, squeeze, compressibility and static bearing. To determine the dynamic model coefficients, numerical simulation of different cases between displacement and dynamic force of oil film are performed with fluent code. Simulation results show that hydrostatic guidway can be taken as a linear system when it is subjected to a small oscillation amplitude. Based on a dynamic model and numerical simulation, every dynamic model’s parameters are calculated by the Levenberg-Marquardt algorithm. Identification results show that “mass-spring-damper” model is the most appropriate dynamic model of the hydrostatic guidway. This paper provides a reference and preparation for the analysis of the dynamic model of the similar hydrostatic bearings.

关键词： hydrostatic guidway     dynamic model     dynamic mesh technique     Levenberg-Marquardt     mass-spring-damper model    

HTML PDF 收藏

Integration of molecular dynamic simulation and free volume theory for modeling membrane VOC/gas separation

Bo Chen, Yan Dai, Xuehua Ruan, Yuan Xi, Gaohong He

《化学科学与工程前沿（英文）》 2018年 第12卷 第2期   页码 296-305 doi: 10.1007/s11705-018-1701-3

摘要： Gas membrane separation process is highly unpredictable due to interacting non-ideal factors, such as composition/pressure-dependent permeabilities and real gas behavior. Although molecular dynamic (MD) simulation can mimic those complex effects, it cannot precisely predict bulk properties due to scale limitations of calculation algorithm. This work proposes a method for modeling a membrane separation process for volatile organic compounds by combining the MD simulation with the free volume theory. This method can avoid the scale-up problems of the MD method and accurately simulate the performance of membranes. Small scale MD simulation and pure gas permeation data are employed to correlate pressure-irrelevant parameters for the free volume theory; by this approach, the microscopic effects can be directly linked to bulk properties (non-ideal permeability), instead of being fitted by a statistical approach. A lab-scale hollow fiber membrane module was prepared for the model validation and evaluation. The comparison of model predictions with experimental results shows that the deviations of product purity are reduced from 10% to less than 1%, and the deviations of the permeate and residue flow rates are significantly reduced from 40% to 4%, indicating the reliability of the model. The proposed method provides an efficient tool for process engineering to simulate the membrane recovery process.

关键词： membrane vapor separation     membrane process modeling     process engineering     free volume theory     volatile organic compound    

HTML PDF 收藏

Finite element modeling of cable sliding and its effect on dynamic response of cable-supported truss

Yujie YU, Zhihua CHEN, Renzhang YAN

《结构与土木工程前沿（英文）》 2019年 第13卷 第5期   页码 1227-1242 doi: 10.1007/s11709-019-0551-5

摘要： The cable system of cable-supported structures usually bears high tension forces, and clip joints may fail to resist cable sliding in cases of earthquake excitations or sudden cable breaks. A analytical method that considers the dynamic cable sliding effect is proposed in this paper. Cable sliding behaviors and the resultant dynamic responses are solved by combining the vector form intrinsic finite element framework with cable force redistribution calculations that consider joint frictions. The cable sliding effect and the frictional tension loss are solved with the original length method that uses cable length and the original length relations. Then, the balanced tension distributions are calculated after frictional sliding. The proposed analytical method is achieved within MATLAB and applied to simulate the dynamic response of a cable-supported plane truss under seismic excitation and sudden cable break. During seismic excitations, the cable sliding behavior in the cable-supported truss have an averaging effect on the oscillation magnitudes, but it also magnifies the internal force response in the upper truss structure. The slidable cable joints can greatly reduce the ability of a cable system to resist sudden cable breaks, while strong friction resistances at the cable-strut joints can help retain internal forces.

关键词： sliding cable     explicit solution framework     original length method     seismic response     cable rupture    

HTML PDF 收藏

Modeling of dynamic response of poroelastic soil layers under wave loading

Mehmet Bar?? Can üLKER

《结构与土木工程前沿（英文）》 2014年 第8卷 第1期   页码 1-18 doi: 10.1007/s11709-014-0233-2

摘要： In this paper, the dynamic response of saturated and layered soils under harmonic waves is modeled using the finite element method. The numerical results are then verified by corresponding analytical solutions which are also developed by the author. The equations governing the dynamics of porous media are written in their fully dynamic form and possible simplifications are introduced based on the presence of inertial terms associated with solid and fluid phases. The response variations are presented in terms of pore water pressure and shear stress distributions within the layers. It is determined that a set of non-dimensional parameters and their respective ratios as a result of layering play a major role in the dynamic response.

关键词： dynamic response of soils     coupled flow-deformation     finite elements     analytical solution     harmonic waves    

HTML PDF 收藏

of carbon dioxide photoreduction process in a laboratory-scale photoreactor by computational fluid dynamicand reaction kinetic modeling

《化学科学与工程前沿（英文）》 2022年 第16卷 第7期   页码 1149-1163 doi: 10.1007/s11705-021-2096-0

摘要： The production of solar fuels via the photoreduction of carbon dioxide to methane by titanium oxide is a promising process to control greenhouse gas emissions and provide alternative renewable fuels. Although several reaction mechanisms have been proposed, the detailed steps are still ambiguous, and the limiting factors are not well defined. To improve our understanding of the mechanisms of carbon dioxide photoreduction, a multiphysics model was developed using COMSOL. The novelty of this work is the computational fluid dynamic model combined with the novel carbon dioxide photoreduction intrinsic reaction kinetic model, which was built based on three-steps, namely gas adsorption, surface reactions and desorption, while the ultraviolet light intensity distribution was simulated by the Gaussian distribution model and Beer-Lambert model. The carbon dioxide photoreduction process conducted in a laboratory-scale reactor under different carbon dioxide and water moisture partial pressures was then modeled based on the intrinsic kinetic model. It was found that the simulation results for methane, carbon monoxide and hydrogen yield match the experiments in the concentration range of 10−4 mol·m–3 at the low carbon dioxide and water moisture partial pressure. Finally, the factors of adsorption site concentration, adsorption equilibrium constant, ultraviolet light intensity and temperature were evaluated.

关键词： carbon dioxide photoreduction     computational fluid dynamic simulation     kinetic model     Langmuir adsorption    

HTML PDF 收藏

Dynamic response surface methodology using Lasso regression for organic pharmaceutical synthesis

《化学科学与工程前沿（英文）》 2022年 第16卷 第2期   页码 221-236 doi: 10.1007/s11705-021-2061-y

摘要： To study the dynamic behavior of a process, time-resolved data are collected at different time instants during each of a series of experiments, which are usually designed with the design of experiments or the design of dynamic experiments methodologies. For utilizing such time-resolved data to model the dynamic behavior, dynamic response surface methodology (DRSM), a data-driven modeling method, has been proposed. Two approaches can be adopted in the estimation of the model parameters: stepwise regression, used in several of previous publications, and Lasso regression, which is newly incorporated in this paper for the estimation of DRSM models. Here, we show that both approaches yield similarly accurate models, while the computational time of Lasso is on average two magnitude smaller. Two case studies are performed to show the advantages of the proposed method. In the first case study, where the concentrations of different species are modeled directly, DRSM method provides more accurate models compared to the models in the literature. The second case study, where the reaction extents are modeled instead of the species concentrations, illustrates the versatility of the DRSM methodology. Therefore, DRSM with Lasso regression can provide faster and more accurate data-driven models for a variety of organic synthesis datasets.

关键词： data-driven modeling     pharmaceutical organic synthesis     Lasso regression     dynamic response surface methodology    

HTML PDF 收藏

A total torque index for dynamic performance evaluation of a radial symmetric six-legged robot

Kejia LI, Xilun DING, Marco CECCARELL

《机械工程前沿（英文）》 2012年 第7卷 第2期   页码 219-230 doi: 10.1007/s11465-012-0320-9

摘要：

This article focuses on the dynamic index and performance of a radial symmetric six-legged robot. At first the structure of the robot is described in brief and its inverse kinematics is presented. Then the dynamic model is formulated as based on the Lagrange equations. A novel index of total torque is proposed by considering the posture of the supporting legs. The new index can be used to optimize the leg’s structure and operation for consuming minimum power and avoiding unstable postures of the robot. A characterization of the proposed six-legged robot is obtained by a parametric analysis of robot performance through simulation using the presented dynamic model. Main influences are outlined as well as the usefulness of the proposed performance index.

关键词： six-legged robots     dynamic modeling     performance index    

HTML PDF 收藏

Simulate oil spill weathering with system dynamic model

Aihaiti KASIMU, Junran DONG, Yuan BIAN, Desheng WU

《工程管理前沿（英文）》   页码 696-696 doi: 10.1007/s42524-019-0060-1

摘要： Numerous oil spill fate and trajectory models have been recently developed to predict oil spill weathering processes. However, these models separately predicted the fate of spilled oil and the change in oil properties. A system dynamic model is thus developed based on the most significant oil weathering processes, which include spreading, evaporation, dispersion into the water bulk, emulsification, and changes in viscosity and density. We employ differential equations to describe these main oil weathering processes, which vary and have different effects on each other. Oil density and viscosity are functions of evaporation and emulsification and change over time. Oil evaporation is the most important process and removes most of the spilled oil from sea surface. Considering the main oil weathering processes, our model provides a different method of predicting the fate of oil and changes in oil properties. The Alaska North Slope is selected as a case study, and the estimated fractions of evaporation are 19% and 16% at 273 K and 283 K, respectively, within 240 h. Simulation results of oil properties and fates are also presented in this study.

关键词： oil spill     weathering     modeling     system dynamics    

HTML PDF 收藏

The computational fluid dynamic modeling of downwash flow field for a six-rotor UAV

Yongjun ZHENG, Shenghui YANG, Xingxing LIU, Jie WANG, Tomas NORTON, Jian CHEN, Yu TAN

《农业科学与工程前沿（英文）》 2018年 第5卷 第2期   页码 159-167 doi: 10.15302/J-FASE-2018216

摘要： The downwash flow field of the multi-rotor unmanned aerial vehicle (UAV), formed by propellers during operation, has a significant influence on the deposition, drift and distribution of droplets as well as the spray width of the UAV for plant protection. To study the general characteristics of the distribution of the downwash airflow and simulate the static wind field of multi-rotor UAVs in hovering state, a 3D full-size physical model of JF01-10 six-rotor plant protection UAV was constructed using SolidWorks. The entire flow field surrounding the UAV and the rotation flow fields around the six rotors were established in UG software. The physical model and flow fields were meshed using unstructured tetrahedral elements in ANSYS software. Finally, the downwash flow field of UAV was simulated. With an increased hovering height, the ground effect was reduced and the minimum current velocity increased initially and then decreased. In addition, the spatial proportion of the turbulence occupied decreased. Furthermore, the appropriate operational hovering height for the JF01-10 is considered to be 3 m. These results can be applied to six-rotor plant protection UAVs employed in pesticide spraying and spray width detection.

关键词： CFD simulation     downwash flow field     numerical analysis     plant protection     six-rotor UAV    

HTML PDF 收藏

Comprehensive analysis of the influence of structural and dynamic parameters on the accuracy of nano-precision

Chengyuan LIANG, Fang YUAN, Xuedong CHEN, Wei JIANG, Lizhan ZENG, Xin LUO

《机械工程前沿（英文）》 2019年 第14卷 第3期   页码 255-272 doi: 10.1007/s11465-019-0538-x

摘要： Nano-precision positioning stages are characterized by rigid-flexible coupling systems. The complex dynamic characteristics of mechanical structure of a stage, which are determined by structural and dynamic parameters, exert a serious influence on the accuracy of its motion and measurement. Systematic evaluation of such influence is essential for the design and improvement of stages. A systematic approach to modeling the dynamic accuracy of a nano-precision positioning stage is developed in this work by integrating a multi-rigid-body dynamic model of the mechanical system and measurement system models. The influence of structural and dynamic parameters, including aerostatic bearing configurations, motion plane errors, foundation vibrations, and positions of the acting points of driving forces, on dynamic accuracy is investigated by adopting the H-type configured stage as an example. The approach is programmed and integrated into a software framework that supports the dynamic design of nano-precision positioning stages. The software framework is then applied to the design of a nano-precision positioning stage used in a packaging lithography machine.

关键词： nano-precision positioning stage     analysis and design     structural and dynamic parameters     dynamic accuracy     systematic modeling    

HTML PDF 收藏

Dynamic fate modeling of γ-hexachlorocyclohexane in the lower reaches of the Liao River

LIU Zhenyu, YANG Fenglin, QUAN Xie, ZHANG Xiaohong

《环境科学与工程前沿（英文）》 2007年 第1卷 第2期   页码 166-171 doi: 10.1007/s11783-007-0029-x

摘要： A QWASI model dependent on temperature is parameterized to describe the long-term fate of persistent organic pollutants (POPs) in the Liao River. The model parameters, namely fugacity capacity, degradation rate, and transfer coefficient, are profoundly affected by temperature. This model is used to simulate the fate of γ-hexachlorocyclohexane (γ-HCH) in the lower reaches of the Liao River from 1998 to 2008. Modeling results show that γ-HCH fugacity capacities in air, water, and sediment increase as temperature decreases, and the transfer and transformation rate coefficients increase as temperature increases. The variations of transfer and transformation parameter values depend on fugacity capacities, and transfer and transformation coefficients simultaneously. The performance of the model is evaluated by comparing the predicted and observed concentrations in the water and sediment of the Liao River. The predicted values agree well with the observed value in the order of magnitude, in most cases within the factor of 3. It is believed that the model is appropriate for simulating the long term fate of POPs in the Liao River.

关键词： coefficient     POPs     temperature     sediment increase     dependent    

HTML PDF 收藏

Dynamic modeling of flexible-links planar parallel robots

DU Zhaocai, YU Yueqing, ZHANG Xuping, DU Zhaocai

《机械工程前沿（英文）》 2008年 第3卷 第2期   页码 232-237 doi: 10.1007/s11465-008-0032-3

摘要： This paper presents a finite element-based method for dynamic modeling of parallel robots with flexible links and rigid moving platform. The elastic displacements of flexible links are investigated while considering the coupling effects between links due to the structural flexibility. The kinematic constraint conditions and dynamic constraint conditions for elastic displacements are presented. Considering the effects of distributed mass, lumped mass, shearing deformation, bending deformation, tensile deformation and lateral displacements, the Kineto-Elasto dynamics (KED) theory and Lagrange formula are used to derive the dynamic equations of planar flexible-links parallel robots. The dynamic behavior of the flexible-links planar parallel robot is well illustrated through numerical simulation of a planar 3-RR parallel robot. Compared with the results of finite element software SAMCEF, the numerical simulation results show good coherence of the proposed method. The flexibility of links is demonstrated to have a significant impact on the position error and orientation error of the flexible-links planar parallel robot.

关键词： 3-RR parallel     KED     coupling     software SAMCEF     orientation    

HTML PDF 收藏

标题 作者 时间 类型 操作

PRESS-based EFOR algorithm for the dynamic parametrical modeling of nonlinear MDOF systems

Haopeng LIU, Yunpeng ZHU, Zhong LUO, Qingkai HAN

期刊论文

Mesh relationship modeling and dynamic characteristic analysis of external spur gears with gear wear

期刊论文

Special issue: Wind turbine dynamic modeling, condition monitoring and diagnosis

Zheng YOU, Jinji GAO, Fulei CHU, Tielin SHI

期刊论文

Dynamic modeling of hydrostatic guideway considering compressibility and inertia effect

Yikang DU,Kuanmin MAO,Yaming ZHU,Fengyun WANG,Xiaobo MAO,Bin LI

期刊论文

Integration of molecular dynamic simulation and free volume theory for modeling membrane VOC/gas separation

Bo Chen, Yan Dai, Xuehua Ruan, Yuan Xi, Gaohong He

期刊论文

Finite element modeling of cable sliding and its effect on dynamic response of cable-supported truss

Yujie YU, Zhihua CHEN, Renzhang YAN

期刊论文

Modeling of dynamic response of poroelastic soil layers under wave loading

Mehmet Bar?? Can üLKER

期刊论文

of carbon dioxide photoreduction process in a laboratory-scale photoreactor by computational fluid dynamicand reaction kinetic modeling

期刊论文

Dynamic response surface methodology using Lasso regression for organic pharmaceutical synthesis

期刊论文

A total torque index for dynamic performance evaluation of a radial symmetric six-legged robot

Kejia LI, Xilun DING, Marco CECCARELL

期刊论文

Simulate oil spill weathering with system dynamic model

Aihaiti KASIMU, Junran DONG, Yuan BIAN, Desheng WU

期刊论文

The computational fluid dynamic modeling of downwash flow field for a six-rotor UAV

Yongjun ZHENG, Shenghui YANG, Xingxing LIU, Jie WANG, Tomas NORTON, Jian CHEN, Yu TAN

期刊论文

Comprehensive analysis of the influence of structural and dynamic parameters on the accuracy of nano-precision

Chengyuan LIANG, Fang YUAN, Xuedong CHEN, Wei JIANG, Lizhan ZENG, Xin LUO

期刊论文

Dynamic fate modeling of γ-hexachlorocyclohexane in the lower reaches of the Liao River

LIU Zhenyu, YANG Fenglin, QUAN Xie, ZHANG Xiaohong

期刊论文

Dynamic modeling of flexible-links planar parallel robots

DU Zhaocai, YU Yueqing, ZHANG Xuping, DU Zhaocai

期刊论文