A new average response spectrum method for linear response analysis of structures to spatial earthquake ground motions

The differences in support motions may have significant effects on the seismic responses of large space structures. However, most practical design codes still remain unsatisfactory in terms of ground motion variations for large space structures. Selecting two-line-support large space structures as the research object, the paper proposes an efficient method, called the average response spectrum method, to calculate the linear responses of this kind of structure when the spatial effects are taken into account. The significant advantage of the method is that the linear peak seismic structural responses considering the spatial effects can be obtained as easily as the conventional response spectrum method does. A gable lattice frame is then studied as a numerical example when the wave passage effect is included. Computation results reveal that the internal forces of the structure are magnified by the spatial effects so that they cannot be ignored in engineering practice. The analyses also illustrate the validity and precision of the average response spectrum method.