DYNAMIC ASSESSMENT OF COMPOSITE STEEL-DECK FLOORS UNDER HUMAN-INDUCED ACTIVITIES

Abstract

Ambient and force vibration tests carried out on a steel-deck interior bay are presented.  This bay is supported on joist and girders. The modelling of the steel-deck interior bay was detailed, the concrete was meshed with 3D solid finite elements, the deck with shell finite elements, beams and columns with frame finite elements and the welded steel mesh with bar finite elements. The numerical models are validated with the natural frequency and accelerations registered for human induced activities in experimental tests.

A parametric study of the variables which affects the natural frequency and acceleration in steel-deck systems under human induced activities is caried out. The studied variables are: steel-deck gauge, concrete thickness above the top of the steel deck, joist spacing, bay size, increment on the moment of inertia of joist, girders and columns, increment of the elastic modulus of the concrete and the use of lightweight concrete in the slab. As a result of the parametric study, the variables with greater influence in the natural frequency are the thickness of the concrete slab, joist and girder spacing, but the steel-deck gauge has no influence on it. To reduce the acceleration induced by human activities, it is recommended the increment on the moment of inertia of joist, the increment of the thickness of the concrete slab but with lightweight concrete and the increment of the elastic modulus of the concrete. It is demonstrated that other modes, different to the fundamental one, have greater influence in the response under human-induced activities.