Investigation into the Dynamic Instability Behaviour of 3D Industrial Structures Subjected to the Finite Duration and Step

One of the most significant problems in the dynamic behaviour of industrial structures is the effect of impulsive loading of industrial machinery on the instability of these structures. In design codes, the effects of impulsive loading have been represented by appropriate coefficients in order to transform the dynamic loads into the equivalent static loads. However due to the dynamic nature of impulsive loads, investigation into the instability behaviour of these structures should be undertaken considering the dynamic instability criteria. In the present paper, dynamic instability behaviour of three dimensional industrial space structures subjected to the impulsive loading of industrial machinery, set up in the first floor of these buildings, have been investigated using (geometric and material) nonlinear dynamic analysis. The half-sine-wave, triangular and rectangular impulsive loads with different time duration as well as step loading have been used to apply the impulsive effects of industrial machinery on this type of structures. The obtained results from the nonlinear dynamic analyses have been used to compare with the design criteria presented by design codes and some recommendations have been suggested to modify the design of these structures.