No abstract

No abstract

No abstract

No abstract

No abstract

The vibrations due to earthquake ground motions or due to operations of heavy machineries, can affect the functionality of equipment and cause structural damages to the structures and surrounding equipment. The wire rope isolator (WRI), a type of passive isolator is known to be effective in isolating the vibrations and shock, can be used for vibration isolation of structures and equipment. The primary advantage of WRI is that, it can provide isolation in all three planes and in any orientation. The load-supporting capability of WRI is identified from the static stiffness in the loading direction. The static stiffness depends mainly on the geometrical and material properties of the WRI. The present work involves in the development of an analytical model for the static stiffness in the vertical direction using Castigliano's second theorem and validated with the experimental results obtained from the monotonic loading test.The flexural rigidity of the wire ropes required in the model was obtained from the transverse bending test. The analytical model is then used to perform a parametric analysis on the effects of wire rope diameter, width, height, and number of turns (loops) on the vertical stiffness. It is observed that the wire rope diameter influences the stiffness significantly more than the other geometric parameters. The developed model can be accurately used for the evaluation and design of wire rope isolators.

This paper presents an analytical model for the static lateral stiffness of Wire Rope Isolators (WRI). The wire rope isolator, which is a passive isolation device, has been widely adopted as a shock and vibration isolation for many types of equipment and lightweight structures. The major advantage of the WRI is its ability to provide isolation in all three planes and in any orientation. The WRI in the lateral roll mode, is required to possess the required lateral stiffness to support and isolate the equipment effectively. The static lateral stiffness of WRI depends mainly on the geometrical characteristics and wire rope properties. The model developed in this paper is validated experimentally using a series of monotonic loading tests. The flexural rigidity of the wire ropes, which is required in the model, was determined from the transverse bending test on several wire rope cables. It was observed that the lateral stiffness is significantly influenced by the wire rope diameter and height of the isolator. The proposed analytical model can be used for the evaluation of lateral stiffness and in the preliminary design of the WRI.

No abstract