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Case study on the mechanics of NPR anchor cable compensation for large deformation tunnel in soft rock in the Transverse Mountain area,China
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作者 LI Yong ZHENG Jing +3 位作者 HUO Shu-sen WANG Feng-nian HE Man-chao TAO Zhi-gang 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第6期2054-2069,共16页
A study was conducted to analyze the deformation mechanism of strongly weathered quartz schist in the Daliangshan Tunnel,located in the western Transverse Mountain area.A large deformation problem was experienced duri... A study was conducted to analyze the deformation mechanism of strongly weathered quartz schist in the Daliangshan Tunnel,located in the western Transverse Mountain area.A large deformation problem was experienced during the tunnel construction.To mitigate this problem,a support system was designed incorporating negative Poisson ratio(NPR)anchor cables with negative Poisson ratio effect.Physical model experiments,field experiments,and numerical simulation experiments were conducted to investigate the compensation mechanical behavior of NPR anchor cables.The large deformations of soft rocks in the Daliangshan Tunnel are caused by a high ground stress,a high degree of joint fracture development,and a high degree of surrounding rock fragmentation.A compensation mechanics support system combining long and short NPR anchor cables was suggested to provide sufficient counter-support force(approximately 350 kN)for the surrounding rock inside the tunnel.Comparing the NPR anchor cable support system with the original support system used in the Daliangshan tunnel showed that an NPR anchor cable support system,combining cables of 6.3 m and 10.3 m in length,effectively prevented convergence of surrounding rock deformation,and the integrated settlement convergence value remained below 300 mm.This study provides an effective scientific basis for resolving large deformation problems in deeply buried soft rocks in western transverse mountain areas. 展开更多
关键词 soft rock large deformation NPR anchor cable physical model numerical simulation compensation mechanics
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Editorial for Multiscale&Multifield Coupling in Geomechanics
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作者 Min Wang Pengzhi Pan +1 位作者 Andrew H.C.Chan Y.T.Feng 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第6期1919-1921,共3页
We are delighted to serve as guest editors for this special issue in the Journal of Rock Mechanics and Geotechnical Engineering.The purpose of this special issue is dedicated to gathering the latest research work on M... We are delighted to serve as guest editors for this special issue in the Journal of Rock Mechanics and Geotechnical Engineering.The purpose of this special issue is dedicated to gathering the latest research work on Multiscale&Multifield Coupling in Geomechanics,where we delve into the intricate interplay of various fields and scales that govern the behavior of geomaterials.In total,30 manuscripts from USA,China,UK,Germany,Canada,India and United Arab Emirates are selected to be included in this issue. 展开更多
关键词 materials. GATHERING mechanics
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An 8-Node Plane Hybrid Element for StructuralMechanics Problems Based on the Hellinger-Reissner Variational Principle
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作者 Haonan Li WeiWang +1 位作者 Quan Shen Linquan Yao 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第2期1277-1299,共23页
The finite element method (FEM) plays a valuable role in computer modeling and is beneficial to the mechanicaldesign of various structural parts. However, the elements produced by conventional FEM are easily inaccurat... The finite element method (FEM) plays a valuable role in computer modeling and is beneficial to the mechanicaldesign of various structural parts. However, the elements produced by conventional FEM are easily inaccurate andunstable when applied. Therefore, developing new elements within the framework of the generalized variationalprinciple is of great significance. In this paper, an 8-node plane hybrid finite element with 15 parameters (PHQ8-15β) is developed for structural mechanics problems based on the Hellinger-Reissner variational principle.According to the design principle of Pian, 15 unknown parameters are adopted in the selection of stress modes toavoid the zero energy modes.Meanwhile, the stress functions within each element satisfy both the equilibrium andthe compatibility relations of plane stress problems. Subsequently, numerical examples are presented to illustrate theeffectiveness and robustness of the proposed finite element. Numerical results show that various common lockingbehaviors of plane elements can be overcome. The PH-Q8-15β element has excellent performance in all benchmarkproblems, especially for structures with varying cross sections. Furthermore, in bending problems, the reasonablemesh shape of the new element for curved edge structures is analyzed in detail, which can be a useful means toimprove numerical accuracy. 展开更多
关键词 8-node plane hybrid element Hellinger-Reissner variational principle locking behaviors structural mechanics problems
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Characteristics of Rock Mechanics Response and Energy Evolution Regime of Deep Reservoirs in the Bozhong Sag,Bohai Bay Basin
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作者 Suogui Shang Kechao Gao +4 位作者 QingbinWang Xinghua Zhang Pengli Zhou Jianhua Li Peng Chu 《Energy Engineering》 EI 2024年第9期2505-2524,共20页
Hydraulic fracturing is a mature and effectivemethod for deep oil and gas production,which provides a foundation for deep oil and gas production.One of the key aspects of implementing hydraulic fracturing technology l... Hydraulic fracturing is a mature and effectivemethod for deep oil and gas production,which provides a foundation for deep oil and gas production.One of the key aspects of implementing hydraulic fracturing technology lies in understanding mechanics response characteristics of rocks in deep reservoirs under complex stress conditions.In this work,based on outcrop core samples,high-stress triaxial compression tests were designed to simulate the rock mechanics behavior of deep reservoirs in Bozhong Sag.Additionally,this study analyzes the deformation and damage law for rock under different stress conditions.Wherein,with a particular focus on combining energy dissipation theory to further understand damage law for deep reservoirs.The experimental results show that regardless of stress conditions,the process of deformation/failure of deep-seated reservoirs goes through five stages:Fracture compaction,newfracture formation,stable fracture expansion,unstable fracture expansion,and post-peak residual deformation.Under different stress conditions,the energy change laws of specimens are similar.The energy dissipation process of rocks corresponds closely to the trend of deformation-failure curve,then displays distinctive stage characteristics.Wherein,in stage of rock fracture compaction,the input energy curve is approximately coincident with the elastic strain energy curve,while the dissipation energy curve remains near zero.With the increase of strain,the growth rate of elastic strain energy increases gradually,but with the deformation entering the crack propagation stage,the growth rate of elastic strain energy slows down and the dissipation energy increases gradually.Finally,in the post-peak stage,rock fracture releases a lot of energy,which leads to the sharp decline of elastic strain energy curve.In addition,the introduction of damage variable D quantifies the analysis of the extent of failure for rocks.During the process of increasing strain,rock damage exhibits nonlinear growth with increasing stress. 展开更多
关键词 Deep rock mechanics triaxial compression energy dissipation damage variable
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Induction System for a Fusion Reactor: Quantum Mechanics Chained up
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作者 Friedrich Björn Grimm 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第1期158-166,共9页
In the quest for a sustainable and abundant energy source, nuclear fusion technology stands as a beacon of hope. This study introduces a groundbreaking quantum mechanically effective induction system designed for magn... In the quest for a sustainable and abundant energy source, nuclear fusion technology stands as a beacon of hope. This study introduces a groundbreaking quantum mechanically effective induction system designed for magnetic plasma confinement within fusion reactors. The pursuit of clean energy, essential to combat climate change, hinges on the ability to harness nuclear fusion efficiently. Traditional approaches have faced challenges in plasma stability and energy efficiency. The novel induction system presented here not only addresses these issues but also transforms fusion reactors into integrated construction systems. This innovation promises compact fusion reactors, marking a significant step toward a clean and limitless energy future, free from the constraints of traditional power sources. This revolutionary quantum induction system redefines plasma confinement in fusion reactors, unlocking clean, compact, and efficient energy production. 展开更多
关键词 Fusion Reactor Plasma Confinement Quantum mechanics Clean Energy
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Dental Treatment Using Quantum Mechanics for Knee Joint Pain
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作者 Yoshiro Fujii 《Natural Science》 2024年第9期146-149,共4页
In clinical practice, dentists sometimes encounter phenomena that cannot be explained by modern western medical concepts;for example, the patient’s medical symptoms improve by bringing medicines or dentures close to ... In clinical practice, dentists sometimes encounter phenomena that cannot be explained by modern western medical concepts;for example, the patient’s medical symptoms improve by bringing medicines or dentures close to the body. Although it seems difficult to completely elucidate the mechanism through modern western medicine, it can be explained using quantum mechanics. The quantum, the smallest unit of matter composition, exhibits wave-particle duality. The fact that symptoms can be improved simply by bringing dentures or medicines closer to the body indicates that the waves emitted by dentures or medicines interfere with the pathological waves emitted by the pathological site. Thus, the pathological waves are deformed and lead to a change in symptoms. In this way, quantum theory can explain phenomena that are difficult to elucidate in conventional medicine, which are encountered in clinical practice. So far, the author has presented a case of difficulty in raising the upper limb where the symptoms improved without the need for dentures in the mouth by adjusting the dentures outside the mouth. This time, the author would like to introduce a case which the patient’s knee pain improved by adjusting the dentures outside the mouth. 展开更多
关键词 Denture Adjustment Knee Joint Pain Quantum mechanics Wave Interference The Bi-Digital O-Ring Test
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New Approach to Synchronize General Relativity and Quantum Mechanics with Constant “K”-Resulting Dark Matter as a New Fundamental Force Particle
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作者 Siva Prasad Kodukula 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第1期292-302,共11页
Planck scale plays a vital role in describing fundamental forces. Space time describes strength of fundamental force. In this paper, Einstein’s general relativity equation has been described in terms of contraction a... Planck scale plays a vital role in describing fundamental forces. Space time describes strength of fundamental force. In this paper, Einstein’s general relativity equation has been described in terms of contraction and expansion forces of space time. According to this, the space time with Planck diameter is a flat space time. This is the only diameter of space time that can be used as signal transformation in special relativity. This space time diameter defines the fundamental force which belongs to that space time. In quantum mechanics, this space time diameter is only the quantum of space which belongs to that particular fundamental force. Einstein’s general relativity equation and Planck parameters of quantum mechanics have been written in terms of equations containing a constant “K”, thus found a new equation for transformation of general relativity space time in to quantum space time. In this process of synchronization, there is a possibility of a new fundamental force between electromagnetic and gravitational forces with Planck length as its space time diameter. It is proposed that dark matter is that fundamental force carrying particle. By grand unification equation with space-time diameter, we found a coupling constant as per standard model “α<sub>s</sub>” for that fundamental force is 1.08 × 10<sup>-23</sup>. Its energy calculated as 113 MeV. A group of experimental scientists reported the energy of dark matter particle as 17 MeV. Thorough review may advance science further. 展开更多
关键词 General Relativity Quantum mechanics Space Time Dark Matter A New Fundamental Constant “K”
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Teaching Experiment in Engineering Mechanics Based on Simulation Technology:A Case Study
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作者 Jinru Ma 《Journal of Contemporary Educational Research》 2024年第7期277-282,共6页
This paper explores the integration of simulation technology in Engineering Mechanics(EM)teaching in vocational colleges.A case study was conducted using the tensile test as an example,and digital resources,such as co... This paper explores the integration of simulation technology in Engineering Mechanics(EM)teaching in vocational colleges.A case study was conducted using the tensile test as an example,and digital resources,such as colored Mises stress nephograms,were obtained.These resources were integrated into the original curriculum to conduct teaching experiments.The results show that the use of digital resources significantly improved the quality of teaching in EM.The integration of simulation technology in EM teaching provides a promising direction for the improvement of vocational education and the cultivation of high-quality skilled talents.The development and application of more simulation-based teaching cases should be studied by scholars. 展开更多
关键词 Engineering mechanics Simulation technology Teaching experiment TEACHING Vocational education
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Improved Units of Measure in Rotational Mechanics
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作者 Richard James Petti 《World Journal of Mechanics》 2024年第1期1-7,共7页
The SI system of units in rotational mechanics yields correct numerical results, but it produces physically incorrect units of measure in many cases. SI units also violate the principle of general covariance—the gene... The SI system of units in rotational mechanics yields correct numerical results, but it produces physically incorrect units of measure in many cases. SI units also violate the principle of general covariance—the general rule for defining continuous coordinates and units in mathematics and mathematical physics. After 30+ years of wrestling with these problems, the ultimate authority on units of measure has declared that Newton–meter and Joule are not equivalent in rotational mechanics, as they are in the rest of physics. This article proposes a simple modification to SI units called “Nonstandard International units” (“NI units”) until a better name is agreed upon. NI units yield correct numerical results and physically correct units of measure, and they satisfy the principle of general covariance. The main obstacle to the adoption of NI units is the consensus among users that the radius of rotation should have the unit meter because the radius can be measured with a ruler. NI units assigned to radius should have units meter/radian because the radius is a conversion factor between angular size and circumferential length, as in arclength = rθ. To manage the social consensus behind SI units, the author recommends retaining SI units as they are, and informing users who want correct units that NI units solve the technical problems of SI units. 展开更多
关键词 Rotational mechanics Angular Unit TORQUE Moment of Inertia Angular Momentum General Covariance
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Research on the Assessment System of Computational Mechanics Courses Based on the TOPSIS Entropy Weight Model
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作者 Huijun Ning Ruhuan Yu +1 位作者 Qianshu Wang Mingming Lin 《Journal of Contemporary Educational Research》 2024年第6期166-182,共17页
This paper takes the assessment and evaluation of computational mechanics course as the background,and constructs a diversified course evaluation system that is student-centered and integrates both quantitative and qu... This paper takes the assessment and evaluation of computational mechanics course as the background,and constructs a diversified course evaluation system that is student-centered and integrates both quantitative and qualitative evaluation methods.The system not only pays attention to students’practical operation and theoretical knowledge mastery but also puts special emphasis on the cultivation of students’innovative abilities.In order to realize a comprehensive and objective evaluation,the assessment and evaluation method of the entropy weight model combining TOPSIS(Technique for Order Preference by Similarity to Ideal Solution)multi-attribute decision analysis and entropy weight theory is adopted,and its validity and practicability are verified through example analysis.This method can not only comprehensively and objectively evaluate students’learning outcomes,but also provide a scientific decision-making basis for curriculum teaching reform.The implementation of this diversified course evaluation system can better reflect the comprehensive ability of students and promote the continuous improvement of teaching quality. 展开更多
关键词 TOPSIS entropy weight model Computational mechanics Course assessment and evaluation system Assessment model
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Trans-scale mechanics: looking for the missing links between continuum and micro/nanoscopic reality 被引量:5
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作者 Y.L.Bai H.Y.Wang +1 位作者 M.F.Xia F.J.Ke 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2008年第2期111-126,共16页
Problems involving coupled multiple space and time scales offer a real challenge for conventional frame-works of either particle or continuum mechanics. In this paper, four cases studies (shear band formation in bulk... Problems involving coupled multiple space and time scales offer a real challenge for conventional frame-works of either particle or continuum mechanics. In this paper, four cases studies (shear band formation in bulk metallic glasses, spallation resulting from stress wave, interaction between a probe tip and sample, the simulation of nanoindentation with molecular statistical thermodynamics) are provided to illustrate the three levels of trans-scale problems (problems due to various physical mechanisms at macro-level, problems due to micro-structural evolution at macro/micro-level, problems due to the coupling of atoms/ molecules and a finite size body at micro/nano-level) and their formulations. Accordingly, non-equilibrium statistical mechanics, coupled trans-scale equations and simultaneous solutions, and trans-scale algorithms based on atomic/molecular interaction are suggested as the three possible modes of trans-scale mechanics. 展开更多
关键词 Multi-scale Missing-links Continuum mechanics Particle mechanics Trans-scale mechanics
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Deep Learning Applied to Computational Mechanics:A Comprehensive Review,State of the Art,and the Classics 被引量:1
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作者 Loc Vu-Quoc Alexander Humer 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第11期1069-1343,共275页
Three recent breakthroughs due to AI in arts and science serve as motivation:An award winning digital image,protein folding,fast matrix multiplication.Many recent developments in artificial neural networks,particularl... Three recent breakthroughs due to AI in arts and science serve as motivation:An award winning digital image,protein folding,fast matrix multiplication.Many recent developments in artificial neural networks,particularly deep learning(DL),applied and relevant to computational mechanics(solid,fluids,finite-element technology)are reviewed in detail.Both hybrid and pure machine learning(ML)methods are discussed.Hybrid methods combine traditional PDE discretizations with ML methods either(1)to help model complex nonlinear constitutive relations,(2)to nonlinearly reduce the model order for efficient simulation(turbulence),or(3)to accelerate the simulation by predicting certain components in the traditional integration methods.Here,methods(1)and(2)relied on Long-Short-Term Memory(LSTM)architecture,with method(3)relying on convolutional neural networks.Pure ML methods to solve(nonlinear)PDEs are represented by Physics-Informed Neural network(PINN)methods,which could be combined with attention mechanism to address discontinuous solutions.Both LSTM and attention architectures,together with modern and generalized classic optimizers to include stochasticity for DL networks,are extensively reviewed.Kernel machines,including Gaussian processes,are provided to sufficient depth for more advanced works such as shallow networks with infinite width.Not only addressing experts,readers are assumed familiar with computational mechanics,but not with DL,whose concepts and applications are built up from the basics,aiming at bringing first-time learners quickly to the forefront of research.History and limitations of AI are recounted and discussed,with particular attention at pointing out misstatements or misconceptions of the classics,even in well-known references.Positioning and pointing control of a large-deformable beam is given as an example. 展开更多
关键词 Deep learning breakthroughs network architectures backpropagation stochastic optimization methods from classic to modern recurrent neural networks long short-term memory gated recurrent unit attention transformer kernel machines Gaussian processes libraries Physics-Informed Neural Networks state-of-the-art history limitations challenges Applications to computational mechanics Finite-element matrix integration improved Gauss quadrature Multiscale geomechanics fluid-filled porous media Fluid mechanics turbulence proper orthogonal decomposition Nonlinear-manifold model-order reduction autoencoder hyper-reduction using gappy data control of large deformable beam
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Mechanics analysis of vehicle bumping at approach slabs with superelevation 被引量:4
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作者 姚辉 李亮 +1 位作者 谢桦 冯宇 《Journal of Southeast University(English Edition)》 EI CAS 2012年第2期221-228,共8页
In order to analyze the pavement stress caused by vehicle bumping at an approach slab, a simplified four-wheeled bi- axle vehicle-moving model is proposed. The effect of damping and vibration reduction in the process ... In order to analyze the pavement stress caused by vehicle bumping at an approach slab, a simplified four-wheeled bi- axle vehicle-moving model is proposed. The effect of damping and vibration reduction in the process of vehicle-moving is not considered. Based on the position change of vehicle wheels at the approach slab, the vehicle dynamic vibration equations are summarized. Meanwhile, the undetermined coefficients of the vibration equations are obtained using the boundary and initial conditions of the vehicle. The analytical motion solutions of rear and front wheels at different stages are concluded. Consequently, a four-wheeled vehicle model is developed and vibration equations are provided, which can be used to analyze the impact of complicated stress on pavement. The results show that the excessive stress and stress concentration will occur at the approach slab, and it needs to be strengthened. 展开更多
关键词 road engineering mechanics analysis approach slab vehicle model motion equation
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Direct Relativistic Extension of the Madelung-de-Broglie-Bohm Reformulations of Quantum Mechanics and Quantum Hydrodynamics
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作者 Arquimedes Ruiz-Columbié Hira Farooq Luis Grave de Peralta 《Journal of Modern Physics》 2021年第10期1418-1434,共17页
The basic equations of the non-relativistic quantum mechanics with trajectories and quantum hydrodynamics are extended to the relativistic domain. This is achieved by using a Schr<span style="white-space:nowra... The basic equations of the non-relativistic quantum mechanics with trajectories and quantum hydrodynamics are extended to the relativistic domain. This is achieved by using a Schr<span style="white-space:nowrap;">?</span>dinger-like equation, which describes a particle with mass and spin-0 and with the correct relativistic relation between its linear momentum and kinetic energy. Some simple but instructive free particle examples are discussed. 展开更多
关键词 Quantum mechanics Bohm Quantum mechanics Quantum Hydrodynamics Relativistic Quantum mechanics
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Investigation of the Micro-Mechanics of an Extruded Precipitation-Strengthened Magnesium Alloy under Cyclic Loading
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作者 Chuhao Liu Xiaodan Zhang +1 位作者 Huamiao Wang Yinghong Peng 《Journal of Materials Science and Chemical Engineering》 2024年第7期40-52,共13页
Precipitation strengthening is a crucial microscopic mechanism for enhancing the strength of magnesium alloys. In order to elucidate the influence of precipitation on the microscopic deformation mechanisms and macrosc... Precipitation strengthening is a crucial microscopic mechanism for enhancing the strength of magnesium alloys. In order to elucidate the influence of precipitation on the microscopic deformation mechanisms and macroscopic mechanical response of magnesium alloys under cyclic loading conditions, we employed a crystal plasticity model to analyze the stress-strain curves, specific crystal plane diffraction intensities, and the temporal evolution of various microscopic deformation mechanisms and twinning volume fractions for an extruded magnesium alloy, AXM10304, containing coherent precipitates. The research findings indicate that precipitation does not fundamentally alter the microscopic mechanisms of this alloy. However, it hinders twinning during the compression stage, mildly promotes detwinning during the tension stage, and enhances tension secondary hardening by elevating the difficulty of activation of the prismatic slip. 展开更多
关键词 Cyclic Deformation Magnesium Alloy In-Situ Neutron Diffraction Precipitation Strengthening Crystal Plasticity Lattice Strain Mechanism Evolution
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Micro air vehicle-motivated computational biomechanics in bio-flights:aerodynamics,flight dynamics and maneuvering stability 被引量:8
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作者 Hao Liu Toshiyuki Nakata +3 位作者 Na Gao Masateru Maeda Hikaru Aono Wei Shyy 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2010年第6期863-879,共17页
Aiming at developing an effective tool to unveil key mechanisms in bio-flight as well as to provide guidelines for bio-inspired micro air vehicles(MAVs) design,we propose a comprehensive computational framework,whic... Aiming at developing an effective tool to unveil key mechanisms in bio-flight as well as to provide guidelines for bio-inspired micro air vehicles(MAVs) design,we propose a comprehensive computational framework,which integrates aerodynamics,flight dynamics,vehicle stability and maneuverability.This framework consists of(1) a Navier-Stokes unsteady aerodynamic model;(2) a linear finite element model for structural dynamics;(3) a fluidstructure interaction(FSI) model for coupled flexible wing aerodynamics aeroelasticity;(4) a free-flying rigid body dynamic(RBD) model utilizing the Newtonian-Euler equations of 6DoF motion;and(5) flight simulator accounting for realistic wing-body morphology,flapping-wing and body kinematics,and a coupling model accounting for the nonlinear 6DoF flight dynamics and stability of insect flapping flight.Results are presented based on hovering aerodynamics with rigid and flexible wings of hawkmoth and fruitfly.The present approach can support systematic analyses of bio- and bio-inspired flight. 展开更多
关键词 Micro air vehicle Bio-flight Computational mechanics Integrative biomechanics
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Recent advances in theoretical models of respiratory mechanics 被引量:3
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作者 Bo Huo Rui-Rong Fu 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2012年第1期1-7,共7页
As an important branch of biomedical engineering, respiratory mechanics helps to understand the physiology of the respiratory system and provides fundamental data for developing such clinical technologies as ventilato... As an important branch of biomedical engineering, respiratory mechanics helps to understand the physiology of the respiratory system and provides fundamental data for developing such clinical technologies as ventilators. To solve different clinical problems, researchers have developed numerous models at various scales that describe biological and mechanical properties of the respiratory system. During the past decade, benefiting from the continuous accumulation of clinical data and the dramatic progress of biomedical technologies (e.g. biomedical imaging), the theoretical modeling of respiratory mechanics has made remarkable progress regarding the macroscopic properties of the respiratory process, complexities of the respiratory system, gas exchange within the lungs, and the coupling interaction between lung and heart. The present paper reviews the advances in the above fields and proposes potential future projects. 展开更多
关键词 Respiratory mechanics BIOmechanics Gas exchange
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基于SimMechanics机械臂自适应模糊PID控制仿真研究 被引量:4
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作者 匡毅 夏平 《农业装备与车辆工程》 2017年第12期41-44,共4页
针对传统PID控制机械臂在运动中存在跟踪精度低、响应速度慢、动态性能差等问题,提出采用自适应模糊PID控制。通过用Sim Mechanics搭建二自由度机械臂模型,分别运用传统的PID控制和自适应模糊PID控制方案进行仿真并比较上述两种方案控... 针对传统PID控制机械臂在运动中存在跟踪精度低、响应速度慢、动态性能差等问题,提出采用自适应模糊PID控制。通过用Sim Mechanics搭建二自由度机械臂模型,分别运用传统的PID控制和自适应模糊PID控制方案进行仿真并比较上述两种方案控制效果。仿真结果表明,所设计的自适应模糊PID控制器相比传统的PID控制器对控制机械臂运动有更好的控制效果。 展开更多
关键词 机械臂 SIM mechanics 自适应模糊PID 运动控制 轨迹跟踪
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NANO SCIENCE AND ENGINEERING IN SOLID MECHANICS 被引量:2
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作者 Ken P.Chong 《Acta Mechanica Solida Sinica》 SCIE EI 2008年第2期95-103,共9页
According to National Science Foundation (NSF) Director A. Bement, ‘Transformative research is... research driven by ideas that stand a reasonable chance of radically changing our understanding of an important exis... According to National Science Foundation (NSF) Director A. Bement, ‘Transformative research is... research driven by ideas that stand a reasonable chance of radically changing our understanding of an important existing scientific concept or leading to the creation of a new paradigm or field of science is also characterized by its challenge to current understanding or its pathway to new frontiers.' Nanotechnology is one of such frontiers. It is the creation of new materials, devices and systems at the molecular level--phenomena associated with atomic and molecular interactions strongly influence macroscopic material properties with significantly improved mechanical, optical, chemical, electrical... properties. Former NSF Director Rita Colwell in 2002 declared, ‘nanoscale technology will have an impact equal to the Industrial Revolution'. The transcendent technologies include nanotechnology, microelectronics, information technology and biotechnology as well as the enabling and supporting mechanical and civil infrastructure systems and materials. These technologies are the primary drivers of the twenty first century and the new economy. Mechanics is an essential eleraent in all of the transcendent technologies. Research opportunities, education and challenges in mechanics, including experimental, numerical and analytical methods in nanomechanics, carbon nano-tubes, bio-inspired materials, fuel cells, as well as improved engineering and design of materials are presented and discussed in this paper. 展开更多
关键词 nanomechanics experimental mechanics multi-scales simulation and modeling carbon nanotubes energy bio-inspired materials
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基于SimMechanics的脚踏垃圾箱运动学仿真 被引量:1
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作者 孔艳艳 《成都工业学院学报》 2017年第3期14-17,共4页
为研究脚踏垃圾箱的运动学特性,解决箱盖开合度不够等问题,对垃圾箱机构进行运动学仿真。运用Matlab中的Sim Mechanics功能模块绘制结构框图并仿真,获取关键处的位移、速度和角速度仿真曲线。仿真结果表明:该方法无需数学建模和编程,具... 为研究脚踏垃圾箱的运动学特性,解决箱盖开合度不够等问题,对垃圾箱机构进行运动学仿真。运用Matlab中的Sim Mechanics功能模块绘制结构框图并仿真,获取关键处的位移、速度和角速度仿真曲线。仿真结果表明:该方法无需数学建模和编程,具有快捷、准确直观、功能强大等优点。 展开更多
关键词 脚踏垃圾箱 运动学 SIM mechanics
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