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arXiv 2019年

作者： Gamus, Benny Salem, Lior Gat, Amir D. Or, Yizhar Faculty of Mechanical Engineering Technion – Israel Institute of Technology Technion City Haifa3200003 Israel Technion Autonomous Systems Program Technion - Israel Institute of Technology Technion City Haifa3200003 Israel

Crawling is a common locomotion mechanism in soft robots and nonskeletal animals. In this work we propose modeling soft-robotic legged locomotion by approximating it with an equivalent articulated robot with elastic joints. For concreteness we study the inchworm crawling of our soft robot with two bending actuators, via an articulated three-link model. The solution of statically indeterminate systems with stick-slip contact transitions requires for a novel hybrid-quasistatic analysis. Then, we utilize our analysis to investigate the influence of phase-shifted harmonic inputs on performance of crawling gaits, including sensitivity analysis to friction uncertainties and energetic cost of transport. We achieve optimal values of gait parameters. Finally, we fabricate and test a fluid-driven soft robot. The experiments display good agreement with the theoretical analysis, proving that our simple model correctly captures and explains the fundamental principles of inchworm crawling and can be applied to other soft-robotic legged robots. Copyright © 2019, The Authors. All rights reserved.

关键词： Stick-slip

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Wave Energy Converters and Design Considerations for Gulf of Mexico

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Distributed Generation and Alternative Energy Journal 2015年第4期30卷 55-76页

作者： Guiberteau, Kelly Lee, Jim Liu, Yucheng Dou, Yangqing Kozman, Theodore A. Texas A and M University United States Mechanical Engineering and Program Coordinator of Systems Engineering University of Louisiana Lafayette United States ASME SAE ASEE United States Northwestern Polytechnical University United States University of Louisiana Lafayette Louisiana Industrial Assessment Center United States

This article presents an investigational study on wave energy converters (WECs) and the design considerations for possible implementation in the Gulf of Mexico (GOM). The types of WEC available from the market are studied first. The design considerations for implementing a WEC in GOM are then evaluated. There are several different types of devices that can be used in the system design. Each device type has different attributes that may be helpful or hurtful for the area and wave activity in the GOM. From the evaluation there is a recommendation of the optimal device design conditions, and three device types are recommended for further pursuit as design candidates. Six different WEC projects that are currently being developed and most are ready for commercial testing are examined. Our study evaluates the usefulness of the WECs for the GOM, and provides design factors of both physical and economic scaling. The result of this investigation reveals that while none of the devices can be installed "as is" in the GOM because of wave power or geometry requirements, there are some that have the potential to be modified and scaled down to fit the GOM climate.

关键词： Wave power

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Monitoring the navy's strategic reserve of ozone-depleting substances

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NAVAL ENGINEERS JOURNAL 2002年第4期114卷 95-104页

作者： Smith, DE Breslin, DA Toms, GS Norton, P DENNIS E. SMITH PH.D. is currently a statistical consultant for GEO-CENTERS INC. He received a B.A. in Mathematics (magna cum laude)from Wabash College and an M.S. in mathematics an M.S. in statistics and a Ph.D. in statistics from the University of Wisconsin. From November 1973 until February 1999 he was president and principal statistician at Desmatics Inc. where he participated in a number of studies involving the application of statistical methods to various technical problems in the Navy's environmental-protection and auxiliary-machinery programs. Dr. Smith was instrumental in developing the statistical procedures underlying the Navy's ODS reserve monitoring plan. DAVID A. BRESLIN P.E. is the director of technical operations for the Naval Surface Warfare Center and chairs the ASNE/SNAME Joint Committee on Environmental Engineering. He received a master of science in aerospace engineering from Virginia Tech a master of engineering administration in industrial and systems engineering from Virginia Tech and a bachelor of engineering in mechanical engineering from Stevens Institute of Technology. From 1993 to 1997 he was the program manager of the Naval Sea Systems Command's CFC and Halon Elimination Program and played a critical role in establishing the Navy's strategic reserve of ozone-depleting substances. Because of his many efforts he received a Stratospheric Ozone Protection Award in 1995 from the U.S. Environmental Protection Agency in recognition of “exceptional contributions to global environmental protection”. GREGORY S. TOMS P.E. is the CFC &Halon Elimination Program Manager for the Naval Sea Systems Command (NAVSEA). He received a master of science degree in mechanical engineering from the University of Maryland and a B.S. degree in mechanical engineering from West Virginia University. From 1984 to 1997 he was employed at the Naval Surface Warfare Center Carderock Division Annapolis Detachment (formerly David Taylor Research Center)where he worked on the development of advanced cent

The domestic production of the most powerful ozone-depleting substances (ODSs) has permanently ceased and the abundant supplies of a number of refrigerants, fire-fighting agents, and solvents, once taken for granted, are now a thing of the past. The Navy has adopted a successful strategy for addressing the threat posed by the unavailability of ODSs. That strategy includes relying on a strategic reserve of ODSs. Considering that the strategic reserve will play a critical role in sustained Fleet operations into the middle of the century, it is important to record the history of the reserve and to document lessons learned in order to educate future generations that may face similar challenges. This is the third of three papers that cover all aspects of the Navy's strategic reserve of ODSs. Breslin (1999) documented the history of the Navy's effort to size, establish, and monitor a reserve designed to support Fleet operations until the middle of the century. Breslin, Smith, and Toms (2000) addressed in detail the process used to estimate the required size of the reserve, including the survey method, statistical analyses, and sizing algorithms. This paper discusses the Navy's plan for monitoring the Navy's strategic reserves of ODSs and describes the methods used in the monitoring process. In particular it discusses the underlying assumptions and statistical techniques associated with the Navy's prediction of the expected drawdown of the reserves. A comparison of actual data, collected since the strategic reserves began operations in 1995, with the predicted reserve drawdown, is included in the paper.

关键词： Marine engineering

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A statistical method for estimating the life expectancy of certain shipboard equipment

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NAVAL ENGINEERS JOURNAL 2002年第1期114卷 27-32页

作者： Smith, DE Breslin, DA Toms, GS DENNIS E. SMITH PH.D. is a statistical consultant for Geo-Centers Inc. He received a B.A. in mathe-matics (magna cum laude) from Wabash College and an M.S. in mathematics an M.S. in statistics and a Ph.D. in statistics from the University of Wisconsin. From November 1973 until February 1999 he was President and Principal Statistician at Desmatics Inc. where he participated in a number of studies involving the application of statistical methods to various technical problems in the Navy's environmental-protection and auxiliary-machinery programs. Dr. Smith was instrumental in developing the statistical procedures underlying the Navy's ODS reserve monitoring plan. DAVID A. BRESLIN P.E. is the Director of Technical Operations for the Naval Surface Warfare Center and is the chairperson of ASNE's Committee on Environmental Engineering. He received a master of science degree in aerospace engineering from Virginia Tech a master of engineering administration in indus-trial & systems engineering from Virginia Tech and a bachelor of engineering in mechanical engineering from Stevens Institute of Technology. From 1993 to 1997 he was the program manager of the Naval Sea Systems Command's CFC & Halon Elimination Program and played a critical role in establishing the Navy's strategic reserve of ozone-depleting substances. Because of his many efforts he received a Stratospheric Ozone Protection Award in 1995 from the U.S. Environmental Protection Agency in recogni-tion of “exceptional contributions to global environmental protection”. GREGORY S. TOMS P.E. is the CFC & Halon Elimination Program Manager for the Naval Sea Systems Command (NAVSEA). He received a master of science degree in mechanical engineering from the University of Maryland and a B.S. degree in mechanical engineering from West Virginia University. From 1984 to 1997 he was employed at the Naval Surface Warfare Center Carderock Division Annapolis Detachment (formerly David Taylor Research Center) where he worked on the development of advanced cent

This paper reviews an inexpensive statistical-sampling methodology that can be used to determine the attrition rates of certain types of shipboard equipment. The methodology relies on surveys that are conducted in conjunction with regularly scheduled ship visits over a period of time and a statistical analysis of the survey results. The statistical technique allows for reasonably accurate estimates to be made of attrition rates. The specific example cited in this paper is related to galley-type refrigeration equipment, such as salad chillers, beverage dispensers, et cetera. In the case of galley-type refrigeration equipment, the Navy needs to know whether the Fleet's inventory of equipment relying on Class I Ozone-Depleting Substances (ODSs) will be replaced through natural attrition by the end of fiscal year (FY) 2005, at which time supplies of ODS-based refrigerants will no longer be available for use by ship galleys. This paper outlines the process used to gather data, the analysis of the data, and concludes that the Navy's inventory of galley equipment using Class I ODSs will be replaced through natural attrition by the end of FY05. The methodology reviewed by this paper has wider applications. For various types of shipboard equipment, the methodology can also be used to estimate with reasonable accuracy life expectancies, configurations, conditions, and other items of interest.

关键词： Ship equipment

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Synthesis of zeolites from calcareous waste concrete powder

Results in Materials

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Results in Materials 2022年 13卷

作者： Kanda, Yasuyuki Harada, Satori Mechanical Engineering Program School of Engineering Faculty of Engineering University of the Ryukyus 1 Senbaru Nishihara-cho Nakagami-gun Okinawa 903-0213 Japan Mechanical Systems Engineering Course Graduate School of Engineering and Science University of the Ryukyus 1 Senbaru Nishihara-cho Nakagami-gun Okinawa 903-0213 Japan

In this study, zeolites were synthesized from calcareous waste concrete powder (WCP) using a hydrothermal synthesis method. Effective utilization methods of waste concrete are required worldwide for prolonging the final dumping sites’ lifetime and for promoting a society that recycles. Calcareous concrete, which includes many calcium components, has been widely used. The WCP includes mainly calcite (at 66.9%) and quartz. First, we applied hydrothermal synthesis to raw WCP. However, X-ray diffraction analysis (XRD) revealed no zeolite synthesis. Next, we used the same approach on WCP-HCl (WCP with the calcium component removed by HCl treatment). For WCP-HCl, the synthesis of analcime-type zeolites was confirmed based on XRD and simple absorption tests, in which the WCP-HCl color changed from gray to blue upon its absorption of methylene blue. Finally, to determine the analcime synthesis requirements, we experimentally varied the synthesis. Analcime synthesis was observed at temperatures above 433 K after at least 12 h of heating and for NaOH solution concentrations above 2 mol/L. © 2021 The Authors

关键词： Analcime Hydrothermal synthesis method Recycle Waste concrete Zeolite

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Closing the assessment feedback loop: The use of a qualitative formative evaluation process and changes in a multi-year NSF/PENN state GK-12 education project

Closing the assessment feedback loop: The use of a qualitati...

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2002 ASEE Annual Conference and Exposition: Vive L'ingenieur

作者： Henning, Philip H. Haworth, Dan Kisenwether, Elizabeth Talion, Robin Finckh, Oliver Pennsylvania College of Technology Pennsylvania Transp. Institute Penn State University Department of Electrical Technology Pennsylvania College of Technology Williamsport PA Dept. of Mechanical Engineering Penn State University Park Penn State's FutureTruck Project Vehicle Systems and Safety Program Pennsylvania Transp. Institute Pennsylvania State University College of Engineering Prob.-Based Lrng. E.P. Penn State University Park

The changes made as a result of informal feedback gained through qualitative basement techniques in the operation of a three year science, technology, and math education project is discussed. Field visits by the middle school and high school students to the HEV lab facilities serve as a motivation to develop science skills. In the visits, the fellows seek to develop a mentoring relationship with students in the classes. A variety of web-based activities developed by the students, faculty, and researchers provide additional motivation.

关键词： engineering education

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Gaussian Process Port-Hamiltonian systems: Bayesian Learning with Physics Prior

Gaussian Process Port-Hamiltonian Systems: Bayesian Learning...

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IEEE Conference on Decision and Control

作者： Thomas Beckers Jacob Seidman Paris Perdikaris George J. Pappas Department of Electrical and Systems Engineering University of Pennsylvania Philadelphia PA USA graduate program in Applied Mathematics and Computational Science University of Pennsylvania Philadelphia PA USA Department of Mechanical Engineering and Applied Mechanics University of Pennsylvania Philadelphia PA USA

ISBN: (数字)9781665467612

ISBN: (纸本)9781665467629

Data-driven approaches achieve remarkable results for the modeling of complex dynamics based on collected data. However, these models often neglect basic physical principles which determine the behavior of any real-world system. This omission is unfavorable in two ways: The models are not as data-efficient as they could be by incorporating physical prior knowledge, and the model itself might not be physically correct. We propose Gaussian Process Port-Hamiltonian systems (GPPHS) as a physics-informed Bayesian learning approach with uncertainty quantification. The Bayesian nature of GP-PHS uses collected data to form a distribution over all possible Hamiltonians instead of a single point estimate. Due to the underlying physics model, a GP-PHS generates passive systems with respect to designated inputs and outputs. Further, the proposed approach preserves the compositional nature of Port-Hamiltonian systems.

关键词： Uncertainty Gaussian processes Probabilistic logic Data models Bayes methods Behavioral sciences Kernel

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Zirconia coated carbonyl iron particle-based magnetorheological fluid for polishing

Zirconia coated carbonyl iron particle-based magnetorheologi...

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Optical Manufacturing and Testing VIII

作者： Shafrir, Shai N. Romanofsky, Henry J. Skarlinski, Michael Wang, Mimi Miao, Chunlin Salzman, Sivan Chartier, Taylor Mici, Joni Lambropoulos, John C. Shen, Rui Yang, Hong Jacobs, Stephen D. OptiPro Systems 6368 Dean Parkway Ontario NY United States Department of Mechanical Engineering University of Rochester Rochester NY United States Laboratory for Laser Energetics University of Rochester Rochester NY United States Department of Chemical Engineering University of Rochester Rochester NY United States Materials Science Program University of Rochester Rochester NY United States Institute of Optics University of Rochester 240 East River Road Rochester NY 14623 United States

ISBN: (纸本)9780819477163

Aqueous magnetorheological (MR) polishing fluids used in magnetorheological finishing (MRF) have a high solids concentration consisting of magnetic carbonyl iron particles and nonmagnetic polishing abrasives. The properties of MR polishing fluids are affected over time by corrosion of CI particles. Here we report on MRF spotting experiments performed on optical glasses using a zirconia coated carbonyl iron (CI) particle-based MR fluid. The zirconia coated magnetic CI particles were prepared via sol-gel synthesis in kg quantities. The coating layer was ˜50-100 nm thick, faceted in surface structure, and well adhered. Coated particles showed long term stability against aqueous corrosion. "Free" nano-crystalline zirconia polishing abrasives were co-generated in the coating process, resulting in an abrasivecharged powder for MRF. A viable MR fluid was prepared simply by adding water. Spot polishing tests were performed on a variety of optical glasses over a period of 3 weeks with no signs of MR fluid degradation or corrosion. Stable material removal rates and smooth surfaces inside spots were obtained. © 2009 SPIE.

关键词： Magnetorheological fluids

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The effect of solution treatments, cooling rates, and natural aging times on the mechanical properties of 6061-T4 aluminum

The effect of solution treatments, cooling rates, and natura...

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59th Meeting of the Society for Machinery Failure Prevention Technology: Essential Technologies for Successful Prognostics

作者： Cullip-Brennan, P. Ordonez-Chu, A. Villalobos, E. Lee, E. McLennan, J. Clark, R. Ogren, J. Es-Said, O.S. National Science Foundation Research Experience for Undergraduate Program Mechanical Engineering Department Loyola Marymount University Los Angeles CA 90045 United States NAVAIR Code 4342 MS Building 2188 Patuxent River MD 20670-1908 United States Boeing Satellite Systems Inc. 2260 E. Imperial Hwy. EI Segundo CA 90245 United States

The influence of varying the thermal processing parameters on the physical and mechanical properties of 6061-T4 aluminum alloy was studied. The variables altered were solution treatment temperatures, quenching media and natural aging durations. The influence of varying these parameters on the tensile strength, electrical resistivity and hardness of the alloy is discussed and correlated.

关键词： Hardness

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TEST AND EVALUATION OF THE REVERSIBLE CONVERTER COUPLING REVERSE REDUCTION GEAR

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NAVAL ENGINEERS JOURNAL 1988年第3期100卷 128-142页

作者： NUFRIO, RP The author is a project manager in the Technical Coordination Office Naval Ship Systems Engineering Station (NAVSSES) Philadelphia Pennsylvania. He participated in the cooperative education program at Drexel University graduating in 1983 with his BS degree in mechanical engineering. For three years of his industrial cooperative engineering education along with three years after graduation Mr. Nufrio worked in the NAVSSES Machinery Systems Branch Gas Turbine Section. Recently he managed the operation and completion of the Reverse Reduction Gear Land Based Test Site test and evaluation program.

The Reversible Converter Coupling (RCC), designed and manufactured by Franco Tosi Industrial of Italy, underwent testing at the Naval Ship systems engineering Station (NAV-SSES) Philadelphia, Pa. in March 1984. The Franco Tosi RCC concept can be simply described as a conventional hydraulic coupling (i.e., input or pump rotor driving an output or turbine rotor) with a set of stationary blades that can be inserted between the two rotors to reverse the fluid direction and hence the output rotor direction. The purpose of this testing was to test and evaluate a main propulsion reverse reduction gear concept, using the Franco Tosi RCC, for its compatibility and applicability to gas turbine propulsion machinery configurations, specifically the AOE-6 class ship. Satisfactory development of a workable and reliable reversing system permits use of a fixed pitch propeller. The RCC models tested were the Original Type “79,” the Type “79” Prototype, the Type “79” Production, the Type “84” Production, and the Type “84A” Production. A series of tests was conducted to verify rotor integrity, determine RCC efficiency, evaluate machinery interface, and to determine the overall characteristics of the RCC design. Testing revealed that the Type “79” Production RCC was the most suitable for application on gas turbine powered main propulsion systems. The Type “79” RCC design was approximately 10 percentage points higher in astern efficiency than the Type “84” design and, although the structural integrity of the Type “84” design was superior to the Type “79” design, the Type “79” Production RCC was satisfactory for its intended use without introducing any operational restrictions. The Naval Sea systems Command approved the Type “79” Production RCC for the AOE-6 class ship in April 1986, based on the information acquired during testing.

关键词： GEARS

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