Fasteners are widely used in many industrial applications. Their function in many cases is to provide a leak-proof joint at the flange interface. To accomplish this function, fasteners must be clamped with appropriate force. In practice, it is difficult to measure such forces, intermittently or continuously. While measurement using load cells or strain gages is an available option, it tends to be expensive or infeasible due to the constraints imposed by the application. When tightening the fasteners initially or during maintenance, a less accurate method of specifying the bolt-tightening torque for achieving the necessary bolt force is widely followed in industry. These torque values are calculated using published design correlations [1]. Many factors affect such calculations: friction between the threads and collar and flange, age of the fasteners, assumptions about rigidity of the clamped components, being a few among those. Since specific values applicable for individual application are not always be known, fasteners are often over-tightened, resulting in increased stresses in the assembly elements or under tightened, resulting in leakages at the flange interfaces. In the current paper, we introduce the concept of smart fasteners that can visually indicate the tension they are subjected to, and validate it for a widely used industrial fastener size. Results from numerical and experimental studies conducted are presented for UNC 1/2 -13 × 4 1/4″ smart fasteners. Lastly, relationship between bolt-tightening torque and color intensity of the smart fasteners is provided.
Skip Nav Destination
ASME 2011 International Mechanical Engineering Congress and Exposition
November 11–17, 2011
Denver, Colorado, USA
Conference Sponsors:
- ASME
ISBN:
978-0-7918-5489-1
PROCEEDINGS PAPER
Smart Fasteners and Their Application in Flanged Joints Available to Purchase
Babak Eslami,
Babak Eslami
University of Maryland, College Park, MD
Search for other works by this author on:
Randy Ganye,
Randy Ganye
University of Maryland, College Park, MD
Search for other works by this author on:
Chris Bunai,
Chris Bunai
Stress Indicators, Inc., Gaithersburg, MD
Search for other works by this author on:
Chandrasekhar Thamire
Chandrasekhar Thamire
University of Maryland, College Park, MD
Search for other works by this author on:
Babak Eslami
University of Maryland, College Park, MD
Randy Ganye
University of Maryland, College Park, MD
Chris Bunai
Stress Indicators, Inc., Gaithersburg, MD
Chandrasekhar Thamire
University of Maryland, College Park, MD
Paper No:
IMECE2011-64214, pp. 707-714; 8 pages
Published Online:
August 1, 2012
Citation
Eslami, B, Ganye, R, Bunai, C, & Thamire, C. "Smart Fasteners and Their Application in Flanged Joints." Proceedings of the ASME 2011 International Mechanical Engineering Congress and Exposition. Volume 3: Design and Manufacturing. Denver, Colorado, USA. November 11–17, 2011. pp. 707-714. ASME. https://doi.org/10.1115/IMECE2011-64214
Download citation file:
27
Views
Related Articles
Thread Friction Torque in Bolted Joints
J. Pressure Vessel Technol (November,2005)
Effect of Coating Thickness on the Friction Coefficients and Torque-Tension Relationship in Threaded Fasteners
J. Tribol (April,2009)
An Experimental Study of Bearing and Thread Friction in Fasteners
J. Tribol (April,2005)
Related Chapters
Subsection NG — Core Support Structures
Companion Guide to the ASME Boiler and Pressure Vessel Code, Volume 1, Third Edition
Subsection NG—Core Support Structures
Companion Guide to the ASME Boiler & Pressure Vessel Code, Volume 1, Second Edition
Subsection NG—Core Support Structures
Companion Guide to the ASME Boiler & Pressure Vessel Codes, Volume 1 Sixth Edition