Identification of optimum cable vibration absorbers using fixed-sized-inerter layouts

Cables are widely used in cable-stayed bridges and other civil engineering structures, but they often experience large amplitude vibrations due to their low inherent damping. Recent studies have shown that inerter-based vibration absorbers with two or three elements can provide significant performance improvements with very large inertance. Such large inertance leads to difficulties in physical implementation. Meanwhile, alternative inerter-based layouts with more elements could potentially provide better performance with significantly smaller inertance. However, studying these configurations one by one is impractical because the number of possible absorber layouts increases exponentially with the number of elements. This paper, using two types of fixed-sized-inerter (FSI) layouts, presents an efficient and systematic optimum configuration identification methodology. A simplification procedure is also adopted to then simplify the obtained configurations while not compromising the performance gains. Using this approach, it is shown that when the number of elements is increased from three to four, significant enhancement can be obtained even with small inertance values. The proposed approach can also be applied to vibration problems of other mechanical structures and with other performance criteria.