The influence of structural solutions on dynamic characteristics of steel halls

Metal structures, Dynamics Bachelor degree, semester 5

The objectives of my bachelor's thesis was to check dynamic characteristic of different steel single storey buildings and interpretate the results with the emphasis on the influence structural solutions. I picked three variants of the same hall, which I designed during Metal Structure course. To find the dynamic characteristic of the structures I used Robot Structural Analysis Professional and modelled 2D girder of each solution. I checked ultimate and serviceability limit states of the elements. Then from dynamic analysis I obtained natural frequencies and corresponding shape modes.Finally I interpreted the results.

This is an fragment of my conclusions:

 

If there is necessity of protecting a single storey building from excessive vibration or dynamic effects then the designer should be aware of what influence does the structural solutions have on dynamic characteristic of the building. The example of first and third solution demonstrate how great difference has the chosen solution on natural frequency (150% difference for the first natural frequency). The other aspect may be noticed form the first and the second variants. If you need to change only a little the value of natural frequency of the structure, designer may change the mass distribution to avoid resonance effect.

Codes used:

  • EN 1993 Eurocode 3: Design of steel structures
  • PN-85/B-02170 Ocena szkodliwości drgań przekazywanych przez podłoże na budynki (Polish code)

Programs utilized:

  • Autodesk Autocad
  • Autodesk Robot Structural Analysis Professional