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Damping Even The Smallest Displacements

Bridge with Dampers

(Header Image: chargers.com)

While fluid viscous dampers perform well under seismic loads that result in medium to large displacements, sometimes structures need dampers for smaller displacements. In these cases, low amplitude dampers can be used to apply damping to a more rigid structure that only experiences small displacements from earthquakes, wind and/or pedestrian vibrations.

Developing the Low Amplitude Damper

Interestingly enough, low amplitude dampers were not originally designed for structures. In fact, they weren’t even designed for use here on Earth. As NASA was making remarkable accomplishments in space exploration, one problem engineers kept having was successfully using oil-filled products in space. Even the tiniest vapor outgassing from a conventional seal could cause major problems in the vacuum and weightlessness of space. Taylor Devices was able to solve this problem by developing a product known as the hermetically-sealed, metal bellows damper. Years later, this technology was granted access by the U.S. Government to be used for commercial purposes. The team at Taylor Devices quickly incorporated the low amplitude dampers in structures around the world.

Active Shock Absorber for Space Based Antenna

How Do Low Amplitude Dampers Perform?

Unlike conventional fluid viscous dampers, low amplitude dampers are able to apply damping at very low displacements, even down to 0.001 inches (0.0254mm) or less. How is this possible? It is simply a matter of recognizing the requirements at all frequencies and amplitudes and designing appropriately with the right product. Sometimes, the limiting factor is not actually the configuration and the performance of the damper, but the stiffness of the surrounding structure that will be in the load path of the damper during operation. Since the fluid damper has a “Maxwell” stiffness of its own, and the surrounding structure has stiffness, they both have to be taken into account in the analysis.

From a damper design standpoint, there are many aspects that will allow Taylor Devices’ dampers to operate properly at very low displacements. For example, we often choose to include zero-play (no dead-band) mounting pins that include a press-fit pin with mating brackets that allow installation in the field with simple mounting bolts. Internal damper components are designed to assure proper operation without the use of internal valves or other features that require significant movement before damping force is achieved.

Low Amplitude Damping Testing
Millennium Bridge

Examples of Low Amp Dampers

One example of where low amplitude dampers are used is on the Millennium Bridge in London, England. After initially opening, the bridge was closed, due to large lateral deck motions. Seemingly random pedestrian footfalls were causing resonance of the bridge deck, with lateral accelerations measuring up to 0.25 g. The selected method of retrofit was to add low amplitude dampers that were designed to be used for mitigating the dynamic response of the bridge due to pedestrian traffic. Despite the bridge experiencing foot traffic every day and night, the low amplitude dampers are able to handle the constant low displacement without any degradation in the damper performance or in the dynamic response of the bridge itself.

Damper stroking

Damper on Millennium Bridge stroking

Another structure that utilizes low amplitude dampers is in 250 West 55th Street in New York City. Unlike traditional fluid viscous dampers that would be used in buildings for seismic loads, these dampers were used to protect the building from wind loads. Since the displacements from high winds are much smaller and cyclical, the low amplitude dampers were able to replace some of the braces in the outrigger trusses at the top of the tower and actually cut overall costs of the project.

Damped Outrigger System in 250 West 55th

Contact Taylor Devices

If you would like to learn more about low amplitude dampers from Taylor Devices, please feel to reach out and our team. Whether you have general questions about these dampers and their applications, or you already have a project that needs displacements as low as 0.001 inches (0.0254mm), we are ready to assist you.

Check out the latest episodes of the Damp It Out! Podcast to learn even more about the world of shock and vibration control.

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Craig Winters

Craig Winters

Program Manager – Structural Products

 

Responsibilities

  • Manages all aspects of Structural Projects along with providing full customer service/support.
  • Progresses damper projects from contract execution through completion and interactions throughout the life of any structural project.

Experience

  • 30 years Developing and Building the structural damper market, along with design, manufacturing, testing, and selling of fluid damper products.
  • Managed and supervised over 800 damper projects from inception to completion using specialized devices for structural control of civil engineering structures, including hundreds of applications to improve performance under wind, seismic, pedestrian and traffic shock or vibration, for numerous industrial and structural applications, found on/in buildings, bridges, stadiums, towers, hospitals and many other types of structures.
  • Directed and managed a national and international (world-wide) network of representatives, supporting them with business development, sales visits, technical support, advertising, promotion and general marketing efforts for their various marketplaces.
  • Provided Corporate Representation and Presentations at numerous conferences and meetings annually, including those held by SEAOC, ASCE, AIST, EERI, CTBUH, IBC, and many other international bodies.
  • Publications and Presentations include papers on structural design and control of building and bridge structures including response spectrum analysis/design.

Education

  • MS in Civil/Structural Engineering from University at Buffalo
  • BS in Civil Engineering from University at Buffalo
  • BS in Physics from Fredonia State University

Affiliations

  • SEAOC – Structural Engineers Association Of California
  • ASCE – American Society of Civil Engineers
  • AIST – Association for Iron & Steel Technology
  • EERI – Earthquake Engineering Research Institute
  • CTBUH – Council on Tall Buildings and Urban Habitat

Interests

  • Running 5k and Half-Marathons, Snow-Skiing, Boating and Slalom Waterskiing, Mountain Biking, Hiking, Kayaking and Canoeing, Camping, Sport-Bike (Motorcycle) Riding, and Craft-Beer “tasting”.  Winter weekends are spent coaching Downhill Ski Racing to youths.

Marcus Freeman

Technical Director

Responsibilities

  • Lead technical support efforts for structural engineers in areas of structural analysis with dampers, damper design, peer review and damper implementation (construction) for both new and retrofitted structures
  • Develop technical resources and guidelines for Taylor Damped Moment Frame design
  • Lead Research and Development efforts in advancing Damper implementation in building design

Experience

  • 8 years Structural Engineering design, analysis, and construction administration work with Magnusson Klemencic Associates
  • Lead design engineer experience on high rise residential, convention center, and aviation buildings in high seismic location
  • Registered Professional Engineer in Washington
  • Proficient with the design and detailing of steel moment frames, brace frames, and shear wall systems

Education

  • Virginia Polytechnic Institute and State University Master of Science, Civil Engineering, 2015 Specialization: Structures
  • Virginia Polytechnic Institute and State University Bachelor of Science, Civil Engineering, 2013

Affiliations

  • Structural Engineering Engagement and Equity Committee (NCSEA), Chair, 2021-present
  • SEAW Young Member Group, President, 2017-2018
  • NCSEA Susan Ann “Susie” Jorgensen Presidential Leadership Award – Nov 2023 Issued by National Council of Structural Engineers Associations (NCSEA)

Interests

  • Travel, live music, wine and bourbon tasting, cooking, vinyl collecting

Anthony Tiapon

Senior Project Engineer

Responsibilities

  • Supports clients and engineers with damper design by answering technical questions, providing ETABS support and providing pricing.
  • Performs Non-linear Response History Analysis in ETABS for verifying damper designs.
  • Generates educational materials regarding damper design.

Experience

  • 6 years of structural engineering design work at CYS Structural Engineers, Inc.
  • Experience with seismic and wind design.
  • Structural design experience in retrofit, wood, and steel structures.
  • Registered Professional Engineering in California.

Education

  • B.S. in Architectural Engineering, California Polytechnical State University, San Luis Obispo – 2016

Affiliations

  • Structural Engineers Association of California (SEAOC)
  • National Council of Structural Engineers Association (NCSEA)

Interests

  • Running, working out, hiking, going to concerts and museums, spending time with my dog.
Ben Covich Headshot

Ben Covich

Senior Project Engineer

Responsibilities

  • Assists engineers and clients with damper design, technical support, and pricing.
  • Conduct Non-linear Time History Analysis to verify damper designs.
  • Manage building, bridge and other infrastructure projects from inception to hand off at production.

Experience

  • Design of damper systems using ETABs and Modal Strain Energy methods.
  • Base isolation design (Lead Rubber Bearings and Sliding Pendulum Bearings).
  • Managed full scale testing projects at UCSD for Lead Rubber Bearings and iRDT dampers.
  • Designed, project managed, and full scale tested 2D and 3D isolation platforms at The University of Nevada Reno (UNR).
  • Seismic design of shear wall, reinforced concrete and steel structures in New Zealand.
  • Auto CAD drafting
  • Qualified New Zealand Carpenter focusing on renovation of high end residential homes, Historic Buildings and large scale commercial projects.

 

Education

  • Bachelor of Engineering (Civil), B.E (Hons), The University of Auckland – 2018
  • New Zealand Diploma of Engineering, N.Z.D.E (Civil) – 2014
  • New Zealand Certificate in Carpentry – 2012
  • Seismic Isolation Course CEE729 at UNR – 2020

Affiliations

  • New Zealand Society of Earthquake Engineers (NZSEE)
  • Structural Engineers Association of California (SEAOC)
  • National Council of Structural Engineers Association (NCSEA)
  • Earthquake Engineering Research Institute (EERI)

Interests

  • Anything Motorsport, Midget Racing in California and maintaining a racecar (2023 USAC Western States – Rookie of the Year) Motorcross, BBQ, House Project, Travel

Nathan Canney

Director of Structural Engineering

Responsibilities

  • Train and manage structural engineering team at Taylor to assist engineers in analysis with dampers.
  • Educational outreach and support for structural engineers interested in using dampers for seismic or wind applications.

Experience

  • Structural engineering design work at Magnusson Klemencic Associates (2 years), CYS Structural Engineers, Inc.(3 years) and various internships at Parsons Brinckerhoff Quade & Douglas, MA Wright Engineering, and Forel/Elsesser Engineers, Inc.
  • Registered Professional Engineering in California
  • Experience in structural design for new construction and retrofits, steel, concrete, wood and masonry structures. Design experience for seismic and wind using US and international codes.
  • Faculty in the Department of Civil and Environmental Engineering at Seattle University for four years, teaching undergraduate and graduate students courses including Statics, Mechanics of Materials, Residential Design, Ethics, Performance Based Earthquake Engineering and Building Systems.
  • Research focused on engineering education, engineering ethics and identity formation. Over 70 peer reviewed publications in conference proceedings and journals.

Education

  • Ph.D. in Civil Engineering, University of Colorado, Boulder – 2013
  • M.S. in Structural Engineering, Stanford University – 2010
  • B.S. in Civil Engineering, B.S. in Applied Mathematics, Seattle University – 2006

Affiliations

  • Structural Engineers Association of Central California (SEAOCC)
  • American Society of Civil Engineering (ASCE)
  • American Society for Engineering Education (ASEE)

Interests

  • Woodworking, family time, cooking spectacular meals, backpacking, travel and photography.

Konrad Eriksen

Structural Products Sales Director

Responsibilities

  • Heads up the Structural Business Development Team.
  • Develops Damper projects in the building, bridge and infrastructure markets from concept design through to contract execution.

Experience

  • 35 year’s experience in selling, development and manufacturing of dampers and base isolation systems throughout the world.
  • Built and ran Base Isolation and damper manufacturing facilities in New Zealand and USA.
  • Built and ran a BRB manufacturing plant in USA, contracting to Nippon Steel.
  • Developed and patented 2D and 3D isolation systems for equipment and supercomputers.
  • Introduced, manufactured, and tested viscous dampers through a technology transfer with a Japanese partner for the CPMC Hospital, CA.
  • Designed and built test rigs and presses with up to 4400-ton capacity.
  • 10 years of commercial construction engineering in Wellington, New Zealand specializing in constructability challenges, foundation design, concrete durability.
  • Extensive background in rigging, erecting tower cranes and structural steel.  Designed and executed heavy lifts.

Education

  • Bachelor of Engineering (civil) Canterbury University, New Zealand

Affiliations

  • Structural Engineers Association of Northern California (SEAOC)
  • Earthquake Engineering Research Institute (EERI)

Interests

  • Enduro motorcycling, restoring, building and riding Ducati motorcycles, playing guitar, fishing, shooting, hunting, woodworking.

Thank You!

A Taylor Devices Representative will be in touch shortly.