Comfortable Level Analysis on Floors of Prefabricated Box-Plate Steel Structures with TMD and Their Vibration Control Study

Prefabricated box-plate steel structure floors are a new type of prefabricated structures welded by steel sheets and stiffeners. Through construction of a number of finite element models of box-plate steel structure floors, the aspect ratio, thickness of steel sheet, stiffener spacing, and the influence of installed tuned mass dampers (TMD) on floors of comfortable levels were studied. The results showed that: the aspect ratio increased from 6∶6 to 10∶6, which could reduce vertical fundamental frequencies by up to 29.6% and reduce the vertical peak acceleration excited by pedestrains. Thicknesses of steel sheets increased from 6 mm to 10 mm, which had a little of effect on vertical fundamental frequencies of floors, but significant influence on the vertical peak acceleration by up to 68.8%; That T-stiffener spacing increased from 1.5 m to 3.0 m could reduce the vertical fundamental frequencies by up to 33.8%, simultaneouly, the vertical peak acceleration increased to 0.1 m/s². When the thicknesses of steel sheets were smaller and stiffener spacing was larger, it was easy to cause locad vibration for floors and larger peak acceleration locally. The tuned mass dampers (TMD) could effectively improve masses of floors in vibration as well as floor comfortable levels which could meet the specification requirements.