Departmental Publications, Mechanical Engineering

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https://hdl.handle.net/10919/81189

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Use of Response Surface Metamodels for Identification of Stiffness and Damping Coefficients in a Simple Dynamic System
Rutherford, A.C.; Inman, Daniel J.; Park, G.; Hemez, F.M. (Hindawi, 2005-01-01)
Metamodels have been used with success in many areas of engineering for decades but only recently in the field of structural dynamics. A metamodel is a fast running surrogate that is typically used to aid an analyst or test engineer in the fast and efficient exploration of the design space. Response surface metamodels are used in this work to perform parameter identification of a simple five degree of freedom system, motivated by their low training requirements and ease of use. In structural dynamics applications, response surface metamodels have been utilized in a forward sense, for activities such as sensitivity analysis or uncertainty quantification. In this study a polynomial response surface model is developed, relating system parameters to measurable output features. Once this relationship is established, the response surface is used in an inverse sense to identify system parameters from measured output features.A design of experiments is utilized to choose points, representing a fraction of the full design space of interest, for fitting the response surface metamodel. Two parameters commonly used to characterize damage in a structural system, stiffness and damping, are identified. First changes are identified and located with success in a linear 5DOF system. Then parameter identification is attempted with a nonlinear 5DOF system and limited success is achieved. This work will demonstrate that use of response surface metamodels in an inverse sense shows promise for use in system parameter identification for both linear and weakly nonlinear systems and that the method has potential for use in damage identification applications.
Novel Semi-active Suspension Design Based on Decoupling Skyhook Control
Yao, Jialing; Taheri, Saied; Tian, Songmei; Siramdasu, Yaswanth (SAGE, 2016)
A semi-active suspension design based on the traditional method of skyhook control is not capable of effectively controlling the attitude of the vehicle. However, an innovative approach called decoupling skyhook control allows the attitude of the vehicle body and its vibration characteristics to be effectively controlled. In this paper, a new decoupling skyhook controller for semi-active suspension is presented. Vehicle body motions in the three directions of vertical, pitch, and roll have been adopted to develop three skyhook controllers and directly control the vehicle body attitude. Furthermore, three orientation skyhook control forces are converted into actual damping forces of four adjustable dampers through the input decoupling transformation. The simulation results show that the developed controller is more effective than the traditional skyhook control in improving ride comfort.
Improved LMD, Permutation Entropy and Optimized K-Means to Fault Diagnosis for Roller Bearings
Shi, Zongli; Song, Wanqing; Taheri, Saied (MDPI, 2016-02-25)
A novel bearing vibration signal fault feature extraction and recognition method based on the improved local mean decomposition (LMD), permutation entropy (PE) and the optimized K-means clustering algorithm is put forward in this paper. The improved LMD is proposed based on the self-similarity of roller bearing vibration signal extending the right and left side of the original signal to suppress its edge effect. After decomposing the extended signal into a set of product functions (PFs), the PE is utilized to display the complexity of the PF component and extract the fault feature meanwhile. Then, the optimized K-means algorithm is used to cluster analysis as a new pattern recognition approach, which uses the probability density distribution (PDD) to identify the initial centroid selection and has the priority of recognition accuracy compared with the classic one. Finally, the experiment results show the proposed method is effectively to fault extraction and recognition for roller bearing.
Momentum, March 2016
(Virginia Tech, 2016-04-12)
Momentum is the quarterly magazine of the Department of Mechanical Engineering at Virginia Tech. In this issue: Lead-free piezoelectric material in development; Harnessing the energy of ocean waves; Meet the Hyperloop team; Maleshia Jones - Graduate student with focus.
Momentum, Vol. 1 No. 2
(Virginia Tech, 2016-07-18)
Momentum is the quarterly magazine of the Department of Mechanical Engineering at Virginia Tech. In this issue: Mechanical Engineering's Nuclear Engineering program; EcoCAR3 takes second place; Robotic gloves for medical diagnostics; StreamVane makes jet inlet design efficient, economical; and more.
Momentum, Fall 2016
(Virginia Tech, 2016-10-28)
Momentum is the quarterly magazine of the Department of Mechanical Engineering at Virginia Tech. In this issue: Nano engineering - Scaling up; Coating 3D objects quickly Energy Harvesting - from soldier's backpacks to nuclear monitoring Hyperloop - team readies pod, university to build test track.
Mechanical Engineering 2016 Annual Report
(Virginia Tech, 2016-11-16)
The 2016 Annual Report for the Dept. of Mechanical Engineering at Virginia Tech. This issue contains demographic information, a faculty list and a partial list of laboratories within the ME Dept.
Momentum, Winter 2016
(Virginia Tech, 2016-12-19)
Momentum is the quarterly magazine of the Department of Mechanical Engineering at Virginia Tech. In this issue: Honeywell donates aircraft engines; New Scholarship formed in memory of alum; Flexible solar panel a game changer.
Momentum Winter 2017
(Virginia Tech, 2017)
Momentum is the quarterly magazine of the Department of Mechanical Engineering at Virginia Tech. In this issue: 3-D printing at the nano-scale | QL+ signs on with Senior Design | Corina Sandu elected SAE Fellow | Brian Vick elected to NC State MAE Hall of Fame | Rolls-Royce Ph.D. Day | About Alumni with Nicholas Des Champs | more stories, photos and video from the Virginia Tech Mechanical Engineering Department.
Momentum Fall 2017
(Virginia Tech, 2017)
Momentum is the quarterly magazine of the Department of Mechanical Engineering at Virginia Tech. In this issue: Using sound to increase working memory; Researchers find way to print the unprintable; Building a low-cost UAV to help UNICEF in Malawi; Students earn wins with Dream Machine & golf club grips; Fractals may be key to catching sun's rays; New Feature: About Alumni.
Momentum, Spring 2017
(Virginia Tech, 2017-03-14)
Momentum is the quarterly magazine of the Department of Mechanical Engineering at Virginia Tech. In this issue: Robotics team heads to the UAE; Program gives teachers 3D printers; Rail Technologies Laboratory part of unique DOT University Transportation Center; Professors create portable lab experience ... and more.
Momentum, Summer 2017
(Virginia Tech, 2017-06-21)
Momentum is the quarterly magazine of the Department of Mechanical Engineering at Virginia Tech. In this issue: Building an ExoSuit for Lowe's | In Memoriam: James B. Jones | Simulator adds depth to autonomous vehicle research | Sr. Design Expo | Photos from Graduation and more.
Mechanical Engineering 2017 Annual Report
(Virginia Tech, 2017-10-04)
A comprehensive look at the Virginia Tech Department of Mechanical Engineering for the 2016-2017 Fiscal Year.
Momentum, Winter 2018
(Virginia Tech, 2018)
Momentum is the quarterly magazine of the Department of Mechanical Engineering at Virginia Tech.
Momentum, Summer 2018
(Virginia Tech, 2018)
Momentum is the quarterly magazine of the Department of Mechanical Engineering at Virginia Tech.
Momentum, Fall 2018
(Virginia Tech, 2018)
Momentum is the quarterly magazine of the Department of Mechanical Engineering at Virginia Tech.
Mechanical Engineering 2018 Annual Report
(Virginia Tech, 2018)
A comprehensive look at the Virginia Tech Department of Mechanical Engineering and its accomplishments in 2018.
Momentum, Spring 2018
(Virginia Tech, 2018-03-13)
Momentum is the quarterly magazine of the Department of Mechanical Engineering at Virginia Tech.
Momentum, Fall 2019
(Department of Mechanical Engineering, 2019)
This is the Fall 2019 issue of Momentum, the quarterly magazine of the Department of Mechanical Engineering at Virginia Tech. Each issue looks at research, faculty, students, awards and what's going on in the department.
Momentum, Summer 2019
(Virginia Tech. Department of Mechanical Engineering, 2019)
The Summer 2019 issue of Momentum, the quarterly magazine of the Department of Mechanical Engineering at Virginia Tech. Each issue looks at research, faculty, students, awards and what's going on in the department.