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SSRN 2024年

作者： Pan, Zhelei Cunha, Rafael N. Bai, Yongtao Amorim, David L.N.F. Flórez-López, Julio School of Civil Engineering Chongqing University Shapingba-District Chongqing400045 China Graduate Program in Civil Engineering Federal University of Alagoas Av. Lourival Melo Mota s/n Tabuleiro do Martins Maceió57072-970 Brazil Disaster Research Institute Federal University of Sergipe Av. Marcelo Deda Chagas s/n Rosa Elze São Cristóvão49107-230 Brazil Department of Structural Engineering Engineering School of São Carlos University of São Paulo Av. Trabalhador São -carlense 400 Pq Arnold Schimidt São Carlos13566-590 Brazil

The present paper proposes a new framework for analyzing RC slabs in a chloride corrosive environment, accounting for concrete cracking, reinforcement yielding, and corrosion pits. To simulate the coupling relations, thermodynamic formulations are introduced in the proposed model, and evolution laws for three coupled internal variables—damage, plasticity, and corrosion—are established. Within the framework of Lumped Damage Mechanics and thermodynamic theory, the proposed formulation uses the lowering of Gibbs energy as the driving force to account for the energy dissipation caused by the three internal variables, which are lumped into inelastic lines and relate all numerical parameters to the mechanical properties of the slab. The numerical results of complex networks of cracks, plasticity rotations pattern and corrosion levels, as well as corresponding force-displacement curves, when compared with experimental data, demonstrate significant accuracy of the model. Parameter analysis shows that the proposed model is capable of predicting the durability and service life of reinforced concrete plates subjected to chemo-mechanical loading, considering corrosive environmental factors. © 2024, The Authors. All rights reserved.

关键词： Concrete slabs

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A SUBMARINE CONTROL-SYSTEM TEST VEHICLE

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NAVAL ENGINEERS JOURNAL 1980年第2期92卷 148-155页

作者： SEJD, JJ WATKINSON, KW HILL, WF Mr. James J. Sejd received his B.S. degree in Civil Engineering from Case Western Reserve University and has since undergone considerable graduate study at both The George Washington and American Universities. He served almost four years in the U.S. Navy as a Naval Aviator and enjoys the unique distinction of being qualified in both Heavier- and Lighter-than-Air aircraft. Early in his career he was employed at the Navy's Bureau of Ships in the capacity of a Structural Designer and Structural Research Monitor. In 1966 he joined the Staff of the Center for Naval Analyses where he was involved in the mathematical modeling of ships and aircraft and in economic “trade-off‘ analysis. In 1970. he went to the Naval Ship Engineering Center as an Operations Research Analyst in the Ship Design and Development Division. At the present time he is employed as a Program Manager for the Naval Sea Systems Command Ship Design Research and Development Office. A member of ASNE since 1973 he also is a member of the Association of Scientists and Engineers at NAVSEA the Operations Research Society of America and the Lighter-Than-Air Society. Mr. Kenneth W. Watkinson received both is B.S. and M.S. degrees in Engineering Science from Florida State University in 1970 and 1971 respectively. Since graduation he has been employed at the Naval Coastal Systems Center (NCSC). Panama City. Fla. where he is primarily involved in the investigation of the stability and control of underwater vehicles. For the past four years he has been the Task Leader and Principal Investigator for the NCSC portion of the Advanced Submarine Control Program involved in developing control design methods and the instrumentation system for the Submarine Control System Test Vehicle. Mr. William F. Hill is currently the ASCOP Program Manager at Lockheed Missiles & Space Company (LMSC) Inc. where he has the overall responsibility for design and construction of the Control System Test Vehicle (CSTV). He entered the aircraft industry in England as an Apprentice w

As part of the Advanced Submarine Control program (ASCOP), the Naval Sea Systems Command has developed an open water Submarine Control System Test Vehicle (CSTV). This vehicle is a 1/12 scale model of an SSN 688 Class Submarine, with provisions for easy geometric changes. Such changes include alternate Sail size and location, the addition of parallel middle-bodies, alternative tail sections, and alternative control configurations. A self-contained instrumentation and control system provides the capability for “on-board” recording of all relevant Submarine-state variables, over the entire speed and depth range, to a degree of data accuracy exceeding any known system. With the means thus available to correlate measured vehicle hydrodynamics with selected maneuvers, conditions, and changes in hull geometry and control surface configuration, modern mathematical techniques for improving submarine equations of motion can be employed to permit dramatic design enhancements in both safety and performance. This paper provides the rationale and history of the development of this vehicle, a description of the instrumentation and control package, and a description of the vehicle itself.

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Arsenal ship program certification plan

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NAVAL ENGINEERS JOURNAL 1998年第1期110卷 249-261页

作者： Arntson, S Lind, W Turner, JJ Blaiklock, WC Tedesco, M Stephen G. Arntson is an independent consultant. A degree Naval Architect he has over 38 years of experience in the design construction and maintenance of surface ships. His experience includes 28 yeus with the Naval Sea Systems Command Naval Ship Engineering Centerl Bureau of Ships specializing in the structural design of Naval surface ships and 7 years with ABS Specializing in the application of commercial ship design practices. Most recently he worked with both NASSCO and ABS MZ the Arsenal Ship Program. Steve was very active with the Ships Structure Committee in developing R&D programs for ship structure and he is a member of the ASNE Journal Committee. Steve received a BS in Mechanical Engineering (Naval Architecture Option) from Virginia Polytechnic Institute in 1964. He is a member of the ASNE TAU BETA PI PI TAU SIGMA and PHI KAPPA PHI. William 1. Lind joined ABS in 1992 after ten years with Sparkman and Stephens Inc. He is currently ABS Amekas Manager of Engineering jm New Orleans and Cleveland. Both ofices conduct plan reviews for militavy commercial and private marine craft fm self-propelled vessels under 300 feet in length and bargus unlimited in length. As Vice-Chaimn ojthe Western Rivers Technical Committee Great Lakes Technical Committee and the Small Vessel Committee Bill participated in the writing of the 1997 ABS Guide for Building and Classing High Speed Craft and the 1997 ABS Rules for Building and Classing Steel Vessels Under 9OM. Bill received an MBA from Florida Atlantic University in 1995 a BS in Mechanical Engineering from New York Institute of Technology in 1986 and a BA in Histoy from Colgate University in 1976. He is Chaimn of SNAME HS-9 Composite Panel Testing & Fire Protection and a member of ASNE. John J. Turner is Senior Vice President of SYNTEK Technologies Inc. in Arlington Virginia. SYNTEK specializes in activities of a highly technical nature supporting both industry and government in domestic and international markets. He is a registered Professional Engineer

The Defense Advanced Research Project Agency (DARPA), in conjunction with the U.S. Navy, initiated a research program for the design and construction of a distinctive warship for the 21st century known as the Arsenal Ship. By using an innovative development and acquisition approach it was hoped to streamline the procurement process and reduce costs. In an environment where budgets are being cut, both industry and Government were challenged to develop, design, and produce the innovative ship and related mission systems to meet specific performance capabilities within strict affordability constraints. A key element of this innovative acquisition approach was a new certification scheme designed to replace the traditional test and evaluation (T&E) and acceptance process. The purpose of this paper is to describe the development of the certification plan during Phase LI of the Arsenal Ship program by the American Bureau of Shipping and the contending Shipyard teams, and to discuss the potential benefits of this alternative certification approach. Although the Arsenal Ship program was canceled late in 1997, insight derived from the exploration of new certification concepts could benefit future design and building programs.

关键词： Warships

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Structuring stress for active materials control

arXiv

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arXiv 2019年

作者： Zhang, Rui Redford, Steven A. Ruijgrok, Paul V. Kumar, Nitin Mozaffari, Ali Zemsky, Sasha Dinner, Aaron R. Vitelli, Vincenzo Bryant, Zev Gardel, Margaret L. de Pablo, Juan J. Pritzker School of Molecular Engineering University of Chicago ChicagoIL60637 United States The graduate program in Biophysical Sciences University of Chicago ChicagoIL60637 United States James Franck Institute University of Chicago ChicagoIL60637 United States Department of Bioengineering Stanford University StanfordCA94305 United States Program in Biophysics Stanford University StanfordCA94305 United States Department of Chemistry University of Chicago ChicagoIL60637 United States Department of Physics University of Chicago ChicagoIL60637 United States Department of Structural Biology Stanford University Medical Center StanfordCA94305 United States Center for Molecular Engineering Argonne National Laboratory LemontIL60439 United States

Active materials are capable of converting free energy into mechanical work to produce autonomous motion, and exhibit striking collective dynamics that biology relies on for essential functions. Controlling those dynamics and transport in synthetic systems has been particularly challenging. Here, we introduce the concept of spatially structured activity as a means to control and manipulate transport in active nematic liquid crystals consisting of actin filaments and light-sensitive myosin motors. Simulations and experiments are used to demonstrate that topological defects can be generated at will, and then constrained to move along specified trajectories, by inducing local stresses in an otherwise passive material. These results provide a foundation for design of autonomous and reconfigurable microfluidic systems where transport is controlled by modulating activity with light. Copyright © 2019, The Authors. All rights reserved.

关键词： Nematic liquid crystals

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I Feel Seen: Exposing Students to Minority Speakers Fosters Learning and Community Building

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Microscopy and microanalysis : the official journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada 2023年第1期29卷 2048-2048页

作者： Solares, Maria J. Ott, Troy L. Molecular Cellular Integrative Biosciences Graduate Program Huck Institutes of the Life Sciences Pennsylvania State University University Park PA United States Department of Biomedical Engineering Pennsylvania State University University Park PA United States Center for Structural Oncology Pennsylvania State University University Park PA United States Department of Animal Science Pennsylvania State University University Park PA United States Huck Institutes of the Life Sciences Pennsylvania State University University Park PA United States

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ARCTIC TRAFFICABILITY program - A REVIEW

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NAVAL ENGINEERS JOURNAL 1984年第3期96卷 169-175页

作者： VOELKER, R GLEN, IF SEIBOLD, F BAYLY, I Richard Voelker:is Vice President of ARCTEC Incorporated a firm specializing in cold regions technology. He has been responsible for the management of thePolarClass Traffic-ability Program since its inception and annually participates in the field data collection in the Arctic. His prior experience includes positions with the U.S. Coast Guard in the icebreaker design project the Military Sealift Command and at Newport News Shipbuilding. He is a graduate of N. Y.S. Maritime College and has a MS degree from the University of Michigan. I.F. Glen:received his professional degrees in naval architecture from the Royal Naval Engineering College Manadon Plymouth and RN College Greenwich London entering the Royal Corps of Naval Constructors in 1967. After serving as a Constructor Lieutenant in the Royal Navy's Far East Fleet for a short period he joined the Polaris submarine project team in Bath England in 1968. In 1971 he was seconded to the Canadian Department of National Defense in Ottawa as a Constructor Lieutenant Commander under NATO exchange arrangements where he had responsibilities initially for conventional submarines and latterly for computer aided conceptual design. He ventured to Bath England in 1974 and joined Forward Design Group. In 1975 he took a position as a civilian engineer in the Canadian Defense Department and was Head of Hull Systems Engineering from 1977 to 1979. He joined ARCTEC CANADA LIMITED in 1980 and in addition to managing ice model testing projects and full scale trials has specialized in structural response of ships to ice impact. He headed ARCTEC's Kanata Laboratory from 1981 to 1983 when he was promoted to president. Frederick Seibold:is a research program manager with the Maritime Administration's Office of Advanced Ship Development and Technology. He is responsible for the marine science program which includes research in the areas of ship powering structures and propeller performance and Arctic technology. Mr. Seibold has been employed by Mar Ad since 1961 having hel

This paper describes a multiyear program to make an operational assessment on the feasibility of a year-round Arctic marine transportation system to serve Alaska. Specifically, the three objectives were to: collect meteorological and ice data along potential marine routes; instrument the hull and propulsion machinery to improve design critera for ice-worthy ships; and demonstrate that ships can operate in midwinter Alaskan Arctic ice conditions. The U.S. Coast Guard's Polar class icebreakers were used to make the operational assessment by annually extending the route northward and by operating throughout the winter season. This paper reviews some of the operational and technical achievements to date, as well as plans for future Arctic deployments.

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DEEP SEA ARRAYS FOR MATERIALS EXPOSURE

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NAVAL ENGINEERS JOURNAL 1968年第2期80卷 287-&页

作者： MACANDER, A THE AUTHOR:attended Fairleigh Dickinson University from which he received a B.S. degree in Mechanical Engineering in 1962. He is presently attending Stevens Institute of Technology where he is pursuing a graduate degree in Plastics Engineering. Since 1962 Mr. Macander has been a member of the U. S. Naval Applied Science Laboratory technical staff as a Mechanical Engineer. For the last five years he has been engaged in the development of syntactic foam systems for buoyancy and structural applications in the deep ocean as well as the development of ultrasonic nondestructive test methods for quality assurance of these foam materials. In addition Mr. Macander is responsible for the deep submergence materials exposure program in the ocean being conducted by the U. S. Naval Applied Science Laboratory. He is also a member of the Marine Technology Society.

United States Naval Applied Science Laboratory has been installing and retrieving deep sea mooring installations in southeastern part of Tongue of Ocean (TOTO), Bahamas since 1965;conventional moorings, such as vertical "taut-wire" rope moorings, as well as moorings of more complex design have been used to expose variety of metallic and nonmetallic materials;because of loss of one mooring, multiple recovery systems was designed;new array, materials under exposure, and operations connected with installation are described.

关键词： Undersea technology

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COMPUTER AIDS FOR SHIP DESIGN, INTEGRATION AND CONTROL

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NAVAL ENGINEERS JOURNAL 1980年第2期92卷 73-87页

作者： CARLSON, CM JOHNSON, RA HELMING, FW Mr. Craig M. Carlson received his B.S. degree in Naval Architecture and Marine Engineering from the University of Michigan in 1970 and began his career with the Department of the Navy at the Naval Ship Engineering Center (NAVSEC). In 1972. he returned to the University of Michigan under the NAVSEC Long Term Training Program and received his M.S. degree in Naval Architecture and Marine Engineering. After returning to the Ship Arrangements Branch at NAVSEC. he was assigned as Task Leader for General Arrangements for the PGG PCG PHM. and MCM ship designs and was awarded Outstanding Performance Awards in 1974 and 1975. In addition he was Manager of the Arrangement Subsystem of the Navy's Computer-Aided Ship Design and Construction Program (CASDAC). In October 1979. he became Manager of the CASDAC Hull Design System. Currently. he also is enrolled in the M.S. of Computer Science Program at Johns Hopkins University. Mr. Carlson previously has presented technical papers at ASNE Day 1974 and 1978 as well as at the 1979 DOD Manufacturing Technology Advisory Group Conference. Besides ASNE. which he joined in 1972. he is a member of SNAME. ASE. and the U.S. Naval Institute. Mr. Robert A. Johnson is a Naval Architect in Surface Combatants Design (SEA 03D3). Ship Design Integration Directorate Naval Sea Systems Command. He received an Associate in Engineering degree in Drafting and Design Technology in 1959. his B.S. degree in Aerospace Engineering in 1965. and his M.S. degree in Engineering Mechanics in 1970. all from the Pennsylvania State University. In 1973. he was selected for the NA VSEC Hull Division s Long Term Training Program at the University of Michigan subsequently receiving his M.S.E. degree in Naval Architecture in 1974. Mr. Johnson began his career with the Ordnance Research Laboratory at Pennsylvania State University in 1959 where he worked. on the design of hydroelastic submarine models and conducted research in the area of flow induced structural vibrations. In 1967 he joined HRB-Singer at State Colle

This paper presents an integrated approach to Computer-Aided Ship Design for U.S. Navy preliminary and contract design. An integrated Hull Design System (HDS), currently under development by the Hull Group of the Naval Sea Systems Command (NAVSEA 32). is the vehicle for the discussion. This paper is directed toward practicing ship design professionals and the managers of the ship design process. Primary emphasis of this paper, and of the development effort currently under way, is on aiding ship design professionals in their work. Focus is on integration and management control of the extremely complex set of processes which make up naval ship design. The terminology of the Ship Designer and Design Manager is used. The reader needs no familiarity with the technologies of computer science.

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Machine learning active-nematic hydrodynamics

arXiv

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arXiv 2020年

作者： Colen, Jonathan Han, Ming Zhang, Rui Redford, Steven A. Lemma, Linnea M. Morgan, Link Ruijgrok, Paul V. Adkins, Raymond Bryant, Zev Dogic, Zvonimir Gardel, Margaret L. de Pablo, Juan J. Vitelli, Vincenzo Department of Physics University of Chicago ChicagoIL60637 United States James Franck Institute University of Chicago ChicagoIL60637 United States Pritzer School of Molecular Engineering University of Chicago ChicagoIL60637 United States Graduate Program in Biophysical Sciences University of Chicago ChicagoIL60637 United States Department of Physics Brandeis University WalthamMA02454 United States Department of Physics University of California at Santa Barbara Santa BarbaraCA92111 United States Department of Bioengineering Stanford University StanfordCA94305 United States Department of Structural Biology Stanford University Medical Center StanfordCA94305 United States Center for Molecular Engineering Argonne National Laboratory LemontIL60439 United States

Hydrodynamic theories effectively describe many-body systems out of equilibrium in terms of a few macroscopic parameters. However, such hydrodynamic parameters are difficult to derive from microscopics [1]. Seldom is this challenge more apparent than in active matter where the energy cascade mechanisms responsible for autonomous large-scale dynamics are poorly understood [2-6]. Here, we use active nematics [7-11] to demonstrate that neural networks [12, 13] can extract the spatio-temporal variation of hydrodynamic parameters directly from experiments. Our algorithms analyze microtubule-kinesin [7, 14-16] and actin-myosin [10, 17] experiments as computer vision problems. Unlike existing methods, neural networks can determine how multiple parameters such as activity and elastic constants vary with ATP and motor concentration. In addition, we can forecast the evolution of these chaotic many-body systems solely from image-sequences of their past by combining autoencoder and recurrent networks with residual architecture [18]. Our study paves the way for artificial-intelligence characterization and control of coupled chaotic fields in diverse physical [17, 19] and biological [20-23] systems even when no knowledge of the underlying dynamics exists. Copyright © 2020, The Authors. All rights reserved.

关键词： Proteins

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Motor crosslinking augments elasticity in active nematics

arXiv

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arXiv 2023年

作者： Redford, Steven A. Colen, Jonathan Shivers, Jordan L. Zemsky, Sasha Molaei, Mehdi Floyd, Carlos Ruijgrok, Paul V. Vitelli, Vincenzo Bryant, Zev Dinner, Aaron R. Gardel, Margaret L. The Graduate Program in Biophysical Sciences University of Chicago ChicagoIL60637 United States Institute for Biophysical Dynamics University of Chicago ChicagoIL60637 United States Department of Physics University of Chicago ChicagoIL60637 United States James Franck Institute University of Chicago ChicagoIL60637 United States Department of Chemistry University of Chicago ChicagoIL60637 United States Department of Bioengineering Stanford University StanfordCA94305 United States Pritzker School of Molecular Engineering The University of Chicago ChicagoIL60637 United States Department of Structural Biology Stanford University School of Medicine StanfordCA94305 United States

In active materials, uncoordinated internal stresses lead to emergent long-range flows. An understanding of how the behavior of active materials depends on mesoscopic (hydrodynamic) parameters is developing, but there remains a gap in knowledge concerning how hydrodynamic parameters depend on the properties of microscopic elements. In this work, we combine experiments and multiscale modeling to relate the structure and dynamics of active nematics composed of biopolymer filaments and molecular motors to their microscopic properties, in particular motor processivity, speed, and valency. We show that crosslinking of filaments by both motors and passive crosslinkers not only augments the contributions to nematic elasticity from excluded volume effects but dominates them. By altering motor kinetics we show that a competition between motor speed and crosslinking results in a nonmonotonic dependence of nematic flow on motor speed. By modulating passive filament crosslinking we show that energy transfer into nematic flow is in large part dictated by crosslinking. Thus motor proteins both generate activity and contribute to nematic elasticity. Our results provide new insights for rationally engineering active materials. © 2023, CC BY.

关键词： Elasticity

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