ABSTRACT
Chimneys also exhibit orthogonal mode translational response. However, in this case, torsional mode activity is rarely of concern, since all of the stiffness is normally concentrated around the periphery. In the event that this is not the case because the wall of the chimney is not particularly thick, then shell-type modes of vibration of the chimney wall also become a consideration. Figure 4.9 gives examples of such modes of vibration. In this circumstance, complex modes involving a coupling of shell modes and bending modes complete a rich tapestry of complex modes of vibration.
