Byline: P. S. Balaji (1), Leblouba Moussa (2), M. E. Rahman (1), Lau Hieng Ho (1) Keywords: Flexural rigidity; Isolation; Vertical stiffness; Vibration; Wire rope isolator Abstract: The vibrations caused by earthquake ground motions or the operations of heavy machineries can affect the functionality of equipment and cause damages to the hosting structures and surrounding equipment. A Wire rope isolator (WRI), which is a type of passive isolator known to be effective in isolating shocks and vibrations, can be used for vibration isolation of lightweight structures and equipment. The primary advantage of the WRI is that it can provide isolation in all three planes and in any orientation. The load-supporting capability of the WRI is identified from the static stiffness in the loading direction. Static stiffness mainly depends on the geometrical and material properties of the WRI. This study develops an analytical model for the static stiffness in the vertical direction by using Castigliano's second theorem. The model is validated by using the experimental results obtained from a series of monotonic loading tests. The flexural rigidity of the wire ropes required in the model is obtained from the transverse bending test. Then, the analytical model is used to conduct a parametric analysis on the effects of wire rope diameter, width, height, and number of turns (loops) on vertical stiffness. The wire rope diameter influences stiffness more than the other geometric parameters. The developed model can be accurately used for the evaluation and design of WRIs. Author Affiliation: (1) Faculty of Engineering and Science, Curtin University Sarawak, Miri, 98009, Malaysia (2) Department of Civil and Environmental Engineering, College of Engineering, University of Sharjah, P.O. Box, 27272, Sharjah, UAE Article History: Registration Date: 06/01/2015 Received Date: 26/03/2015 Accepted Date: 25/09/2015 Online Date: 13/01/2016 Article note: Moussa Leblouba received his State Engineer degree from the National School of Public Works, Algiers, Algeria in 2005. Then, he received his Ph.D. degree from the Technical University of Civil Engineering, Bucharest, Romania in 2009. He is currently an Assistant Professor at the Department of Civil and Environmental Engineering at the University of Sharjah, Sharjah, UAE since 2014. His research interests include structural dynamics, finite element analysis, and earthquake engineering. Muhammad Ekhlasur Rahman received his Ph.D. degree from the University of Dublin, Trinity College Dublin, Ireland. He is currently an Associate Professor at the Department of Civil and Construction, Curtin University, Sarawak, Malaysia. His research interests include structural dynamics, finite element analysis, and construction materials. P. S. Balaji received his B.E. degree in Aeronautical Engineering from the Anna University, Chennai, India. He obtained his M.Tech. degrees in Mechanical Design from the NIT, Allahabad, India. He is currently pursuing his Ph.D. degree at the Department of Civil and Construction Engineering, Curtin University, Sarawak, Malaysia. His area of research includes vibrations, finite element analysis, and composite materials. Lau Hieng obtained his Bachelor of Engineering (Honors) and Ph.D. degrees from the Oxford Brookes University, Oxford, United Kingdom. He was the Head of the Civil and Construction Engineering Department from 2005 to 2011. He is currently a professional engineer registered with the Board of Engineers Malaysia. His area of research includes coldformed steel, connections, structural stability, and corrosion.