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Investigation of lubricating and dynamic performances for high-speed spur gear based on tribo-dynamic theory

TRIBOLOGY INTERNATIONAL 2019年 136卷 421-431页

作者： Ouyang, Tiancheng Huang, Guicong Chen, Jingxian Gao, Binxu Chen, Nan Guangxi Univ Coll Mech Engn Nanning Peoples R China Southeast Univ Sch Mech Engn Nanjing Jiangsu Peoples R China

Lubrication and vibration are crucial to the reliability and efficiency of gear device, especially in high-speed, heavy-load condition. In this study, a novel model based on tribo-dynamic theory is introduced to investigate the lubricating and dynamic performances of high-speed spur gear. In conjunction with a finite element model, the time-varying meshing stiffness and static transmission error are derived precisely in the form of Fourier series. An efficient iterative algorithm, integrated Newmark method with multigrid method, is developed for solving the governing equations. The simulation results indicate that it is necessary to utilize tribo-dynamic model to assist lubrication design and vibration control of spur gear in high-speed condition.

关键词： Tribo-dynamic Lubricating Vibration integration algorithm

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Improving the Dynamics of Virtual-Flux-Based Control of Three-Phase Active Rectifiers

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IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS 2014年第1期61卷 177-187页

作者： Gonzalez Norniella, Joaquin Cano, Jose M. Alonso Orcajo, Gonzalo Rojas, Carlos H. Francisco Pedrayes, Joaquin Cabanas, Manes F. Melero, Manuel G. Univ Oviedo Dept Elect Engn Gijon 33204 Spain

Virtual flux (VF)-oriented control (VFOC) and VF-based direct power control (DPC) (VF-DPC) have been developed to improve voltage-oriented control and DPC of three-phase active rectifiers. The VF space vector is utilized in transformations between stationary and rotating coordinates in VFOC and in obtaining instantaneous power in VF-DPC. The VF space vector is calculated by integrating the grid voltage space vector. This integration is usually performed using a first-order low-pass (LP) (FOLP) filter, which counteracts the saturation and dc-drift problems associated with pure integrators. However, the dynamics of FOLP filters can be enhanced to a great extent. This paper presents a new, simple, and fast integration algorithm for VF-based control methods. Simulations and experimental tests on a VF-DPC-based system showed that the proposed algorithm leads to rapid recoveries after grid voltage sags occur. Moreover, the performance of VF-DPC under nonideal grids is discussed.

关键词： Direct power control (DPC) instantaneous active and reactive power integration algorithm power quality three-phase active rectifier virtual flux (VF)

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Finite element formulation for modelling large deformations in elasto-viscoplastic polycrystals

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INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING 2004年第14期60卷 2313-2333页

作者： Matous, K Maniatty, AM Rensselaer Polytech Inst Dept Mech Aerosp & Nucl Engn Troy NY 12180 USA

Anisotropic, elasto-viscoplastic behaviour in polycrystalline materials is modelled using a new, updated Lagrangian formulation based on a three-field form of the Hu-Washizu variational principle to create a stable finite element method in the context of nearly incompressible behaviour. The meso-scale is characterized by a representative volume element, which contains grains governed by single crystal behaviour. A new, fully implicit, two-level, backward Euler integration scheme together with an efficient finite element formulation, including consistent linearization, is presented. The proposed finite element model is capable of predicting non-homogeneous meso-fields, which, for example, may impact subsequent recrystallization. Finally, simple deformations involving an aluminium alloy are considered in order to demonstrate the algorithm. Copyright (C) 2004 John Wiley Sons, Ltd.

关键词： polycrystal finite element integration algorithm finite deformation consistent tangent

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Geomechanical Model for Frictional Contacting and Intersecting Fracture Networks: An Improved 3D Displacement Discontinuity Method

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SPE JOURNAL 2022年第6期27卷 3896-3913页

作者： Fan, Hongzhuo Shao, Jianfu Li, Sanbai Univ Lille Lille France Southern Univ Sci & Technol Shenzhen Key Lab Nat Gas Hydrates Shenzhen Peoples R China

The displacement discontinuity method (DDM) is widely used in large -scale engineering problems, such as hydraulic fracturing stimu-lation in unconventional reservoirs and enhanced geothermal systems, due to its convenient calculation and high precision. Although the 3D-DDM based on triangular elements can more accurately describe intrinsically geometric characteristics of artificial/natural fractures, due to the disadvantage of constant DDM, it will still produce large errors when calculating frictional contacting, close-spacing, and in-tersecting fractures, which greatly limits the universality of DDM in complex fracture networks. To the best of the authors' knowledge, few DDM- based models are capable of tackling partially contacting fracture networks with arbitrary intersecting angles. In this paper, we propose a more efficient 3D-DDM algorithm via integrating the analytical solution, the 20-point Gaussian quadrature formula for standard triangles (GQSTS) integration algorithm, and the adaptive Gaussian-Kronrod integration algorithm. Then, combining the "local mesh refinement " grid, the Mohr-Coulomb correction for negative fracture aperture, and two rough fracture deletion strategies, the optimized 3D-DDM algorithm with broader versatility is established. All optimization measures are validated by the relevant fracture model. In the optimized 3D-DDM algorithm, (1) the "local mesh refinement " technique effectively improves the calculation accuracy of intersect-ing fractures;(2) the adaptive Gaussian-Kronrod integration algorithm not only improves the integration accuracy of high oscillation functions but is also 50% faster than the traditional Gaussian integration algorithm;(3) the Mohr-Coulomb criterion serves as a rigorous constraint for frictional contacting fractures to avoid the occurrence of negative fracture aperture;and (4) using the rough "deep deletion " or "shallow deletion " strategy to replace the ultrahigh-quality mesh generation can more convenie

关键词： hydraulic fracturing aperture artificial intelligence upstream oil & gas complex reservoir intersection line mesh refinement mohr-coulomb correction integration algorithm algorithm

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REDUCED-ORDER MODEL-BASED CONTROL OF THE FLEXIBLE, ARTICULATED-TRUSS SPACE CRANE

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 1995年第1期18卷 135-142页

作者： BANSENAUER, BT BALAS, MJ UNIV COLORADO DEPT AEROSP ENGN SCIBOULDERCO 80309

The large size and extreme flexibility of an articulated space crane entail tremendous difficulties in precision positioning. I Tie demonstrate the application of a low-order control strategy for the flexible system using a linear, Timoshenko beam finite element model. The model captures the system's low-frequency characteristics. From selected modes of the finite element model, we design a reduced-order model (ROM) controller based on an arbitrary crane configuration. The ROM controller rotates the fixed-shape crane about the base alpha joint to actuate position control. This constructive control design takes place in two pieces: design for performance and compensate for stability, Ignoring the presence of residual modes, we design the low-order control law to achieve our performance criteria. Eigenvalue analysis of the closed-loop system, however, shows the destabilizing interaction of the ROM controller with residuals. Adding a parallel bank of residual mode filters, we restore system stability and performance, without redesign of the original controller. Finally,numeric simulation of the controlled finite element model reveals the effectiveness of a ROM-based control law with residual mode filter compensation. Application to a large-scale data-base highlights the utility of this low-order, noniterative controller design.

关键词： Trusses Linear Quadratic Regulator Finite Element Modeling Flexible Structures integration algorithm Large Space Structures Damping Coefficient Structural Dynamics Material Properties Robotics

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Rotation vector in attitude estimation

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2003年第6期26卷 855-860页

作者： Pittelkau, ME Johns Hopkins Univ Appl Phys Lab Laurel MD 20723 USA

An alternative derivation of the spacecraft attitude determination filter is developed to avoid questions of quaternion normalization or attitude matrix orthogonality constraints, quaternion covariance, and subterfuges used to circumvent these problems. This derivation is based on the Bortz equation for the rotation vector. Because the rotation vector is an unconstrained representation of attitude, the aforementioned questions do not arise. Singularities in the state dynamics equation are avoided by maintaining the predicted body attitude as the inertial reference for the filter. A simple discrete solution to the Bortz equation provides accurate attitude propagation for highly maneuverable spacecraft and also in. the presence of jitter.

关键词： Quaternions Maneuverable Spacecraft Spacecraft Attitude White Noise Three Axis Magnetometer integration algorithm Body Reference Frame Euler Angles Aircraft Navigation Systems Dirac Delta Function

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Consistent linearization and finite element implementation of an incrementally objective canonical form return mapping algorithm for large deformation inelasticity

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INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING 2008年第6期75卷 690-708页

作者： Seifert, T. Maier, G. Fraunhofer Inst Mech Mat IWM D-79108 Freiburg Germany

The present paper focuses on the consistent linearization and finite element implementation of an incrementally objective canonical form return mapping algorithm. A general and modular algorithmic setting, suited for almost any rate constitutive equations, is presented where the finite deformation consistent tangent modulus is obtained as a by-product of the integration algorithm. Numerical examples illustrate the good performance of the proposed formulation, especially for large deformation increments with noteworthy superimposed rotation, where the consistent formulation converges quadratically in a reasonable number of iterations. Copyright (C) 2008 John Wiley & Sons, Ltd.

关键词： integration algorithm incremental objectivity finite element implementation consistent linearization

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MIXED FINITE-ELEMENT METHOD FOR COMPOSITE CYLINDER SUBJECTED TO IMPACT

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AIAA JOURNAL 1989年第5期27卷 632-638页

作者： BACHRACH, WE HANSEN, RS SPAULDING FIBRE SMYRNATN

The Hellinger-Reissner variational principle in the time domain is used to formulate a frame-invariant hexahedral element in the natural coordinate system that exhibits high coarse-mesh accuracy for problems involving bending. A modified Hertzian contact law for a sphere on a cylinder is utilized to compute the contact force on the cylinder. The Tsai-Wu failure criterion is used to determine if failure has occurred in the element of the impact region. The element development, low-velocity impact computation, and failure criterion are implemented in an explicit time integration scheme. Results are given for three problems that are used in verifying the time integration code and to view the failure propagation in the impact region of the cylinder. © 1989 American Institute of Aeronautics and Astronautics, Inc., All rights reserved.

关键词： Finite Element Dynamic Analysis Tsai Wu Failure Criterion Hexahedral Element Compressive Strength Normal Stress Composite Laminates integration algorithm Kinetic Energy Newton's Second Law Computer Programs

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Inclusion of Non-Conservative Forces in Geometric Integrators with Application to Orbit-Attitude Coupling

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2021年第7期44卷 1266-1279页

作者： Bolatti, Dante A. de Ruiter, Anton H. J. Ryerson Univ Toronto ON M5B 2K3 Canada Ryerson Univ Dept Aerosp Engn Toronto ON M5B 2K3 Canada

In this paper, a discretization method for incorporating nonconservative forces in a class of geometric numerical integrators known as variational integrators and Galerkin variational propagators is proposed. The proposed method does not require modification of the original integration algorithm used in conservative systems. First, the damped harmonic oscillator is used as benchmark for evaluating the proposed approach. Two more complex scenarios are presented next: one considering propagations in the two-body problem with drag forces, and another dealing with long-term translational propagations about small bodies considering orbit-attitude coupled force terms where the attitude is prescribed. Numerical experiments are performed, comparing results to a nominal analytical solution when it is available, or against a highly accurate propagated reference trajectory. The results in this paper show that including the nonconservative forces in the potential energy term for the discrete equations produces a very accurate discretization. This allows one to perform accurate and fast long-term numerical propagations with structure preserving variational algorithms, in scenarios where perturbations to the system can be modeled as nonconservative forces.

关键词： Damping Coefficient integration algorithm Asteroids Atmospheric Drag Lagrange D'Alembert Principle Numerical integration Numerical Simulation Convergence Analysis Runge Kutta Methods Solar Radiation

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Improvements and algorithmical considerations on a recent three-dimensional model describing stress-induced solid phase transformations

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INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING 2002年第11期55卷 1255-1284页

作者： Auricchio, F Petrini, L Univ Pavia Dipartimento Meccan Strutturale I-27100 Pavia Italy CNR Ist Matemat Applicata & Tecnol Informat I-27100 Pavia Italy

During mechanical loading-unloading cycles shape-memory alloys (SMA) are able to undergo large deformations without showing residual strains (pseudoelasticity) or recovering them through thermal cycles (shape memory effect). Motivated by stress-induced solid phase transformations, these unique behaviours induce the SMA exploitation in innovative and commercially valuable applications, stimulating, consequently, the interest in the development of constitutive models. Also if many models are now available in the literature, effective three-dimensional proposals are still few and limited in several aspects. In this paper, a three-dimensional thermomechanical model recently proposed by Souza et al. (European Journal of Mechanics-A/Solids, 1998;17:789-806.) is taken into consideration;such a model is of particular interest for its effectiveness and flexibility, but it also shows some limitations and missing links in the algorithmical counterparts. This work discusses some improvements to the original model as well as the development and the implementation of a robust integration algorithm to be adopted in a numerical scheme, such as a finite-element framework. Copyright (C) 2002 John Wiley Sons, Ltd.

关键词： shape memory alloys solid phase transformation 3D constitutive model numerical implementation return map integration algorithm

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