Seismic Analysis of Large-Scale Air Duct Hanger Based on ASME-AG1 Specifications

Abstract

Abstract For large-caliber mid-pressure ducts and its supporting rack systems, use the combination of shell units, beam units, and contact units to establish a three-dimensional finite element model of reality structure characteristics. Analyze the inherent frequency of the system. Based on modal analysis results, the eight-level earthquake response spectrum in Shanghai is used as input, a multi-point response spectrum analysis under OBE seismic conditions is performed on the rack system. According to the ASME AG-1 specification, the stress intensity and deformation stiffness assessment of the branch line-type structure under the combination of OBE operating conditions are evaluated. Results showed that the optimal form of the air tube of the A-B section was to increase the seismic oblique support and the inner wall was reinforced. The modeling and assessment methods in the paper have a certain reference value for large-scale duct resistance design and safety assessment.