In order to conduct ambient excitation test for group silos structures,the test model composed of 6( 2 × 3)silos was designed on the background of Shanghai Granary Grain Depots and Berthing Facility Project. Then,the model was analyzed by finite element method,and the rules and characteristics of vibration mode shapes were summarized. Taking the optimized number of measurement points as the principle and combined with the symmetry of the test model,the optimal arrangement scheme and the sensor orientation w...