RANDOM VIBRATION ANALYSIS OF LATTICE SHELLS SUBJECTED TO MULTI-DIMENSIONAL EARTHQUAKE INPUTS

摘要

Lattice shell is a type of spatial structure whose vibrations are dominated by both horizontal and vertical motion. However, most of the researches in the past were only carried out in an assumption that the earthquake inputs to the structure were one-dimensional and independent of each other in three directions. In this paper, a three-dimensional random vibration study is carried out to investigate the seismic performance of lattice shells subjected to multi-dimensional earthquake excitations. The pseudo excitation method for random vibration analysis, proposed by J. H. Lin, is employed and is further developed in the present paper. Based on the method, a computer program is developed and the seismic performance of a spherical lattice shell under multi-dimensional earthquake inputs is studied. The dynamic results for multi-dimensional earthquake inputs are also compared with those for single-dimensional earthquake inputs. Some vibrational characteristics for the shell structure are obtained. It is shown that a significant difference may occur between single and multi-dimensional earthquake inputs.