کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
293336 511127 2008 19 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Two-degree-of-freedom inclined cable galloping—Part 2: Analysis and prevention for arbitrary frequency ratio
موضوعات مرتبط
مهندسی و علوم پایه مهندسی انرژی انرژی های تجدید پذیر، توسعه پایدار و محیط زیست
پیش نمایش صفحه اول مقاله
Two-degree-of-freedom inclined cable galloping—Part 2: Analysis and prevention for arbitrary frequency ratio
چکیده انگلیسی

It has previously been shown that inclined cables and other slender structures can experience galloping instabilities in the critical Reynolds number region, due to the changes in force coefficients, and that coupling of the vibrations in two orthogonal planes can significantly affect the behaviour. It is shown in this paper that for more than a few percent detuning of the natural frequencies, the structural damping required to prevent galloping vibrations tends towards solutions for uncoupled single-degree-of-freedom (DOF) systems. However, the coupling can cause the trajectory of cable motion to be elliptical. Using measured force coefficients for an inclined circular cylinder in the critical Reynolds number range, calculated results of the effective damping and the cable trajectory have been obtained in good agreement with a separate full-scale dynamic cable model test that exhibited galloping behaviour under certain conditions. The special case of sub-critical Reynolds numbers is also addressed. The 1DOF and perfectly tuned 2DOF solutions are considered for inclined circular cables in a horizontal wind from any direction, leading to simple guidelines for the structural damping required in practice to prevent dry inclined cable galloping, for any frequency ratio. Finally, other factors in the behaviour and similarity to rain-wind excitation are discussed.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Wind Engineering and Industrial Aerodynamics - Volume 96, Issue 3, March 2008, Pages 308–326
نویسندگان
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