One of the greatest benefits of steel structures, lightness, has a disadvantage; potential vulnerability to dynamic problems. After construction, it is hard to make adjustments, since only major changes to stiffness, mass and damping can make a significant difference to the response. It is therefore important to design floors for vibration, as in some cases it can be the most onerous criterion when sizing the structural elements.
SCI publication P354 provides a simplified procedure to calculate the response of a floor due to footfall excitation for framing arrangements generally regular in plan. As with every simplified approach to a complex phenomenon, some of the generalising assumptions make the result conservative. Finite Element Analysis provides a means for overcoming this conservatism, but can present significant challenges to inexperienced practitioners.
The SCI has a service to assist engineers with determining a suitable design for floors against vibration. We have recently developed the capability to import BIM models directly into our software, increasing accuracy and reducing cost. After analysis a report of the findings is provided, with suggestions on how to improve the behaviour if required.
In most cases the analysis costs £4000 per floor, no matter the complexity of the structural arrangement. There may be additional fees if extra processing is required.
To discuss any type of floor analysis contact advisory@steel-sci.com