It was deduced that the bobbing group did not absorb energy from the dynamic system. Two plausible reasons for this are: (a) the bobbing group were unable to supply significant energy to the system at the frequency of the second harmonic (b) the bobbing group altered their bobbing style to reduce the response of the grandstand simulator. Structural motion at the bobbing frequency caused a reduction in the dynamic load factor (DLF) at the frequency of the second harmonic while those at the first and third harmonics were unaffected. It was found that significant structural vibration at the bobbing frequency did not increase the effective bobbing load. This paper presents experimental measurement and analysis of rhythmic crowd bobbing loads obtained from tests on a grandstand simulator with two distinct support conditions (a) rigid, and (b) flexible. This is an area of uncertainty in the design and analysis of modern grandstands. Crowd coordination can be unwitting and may be exacerbated by structural motion caused by resonant structural response. It is widely accepted that concerted human activity such as bouncing or bobbing can excite cantilever grandstands. Rhythmic crowd bobbing on a grandstand simulatorĬomer, A.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |