INCABS: A Computer Program for Evaluating Incabinet Spectra

摘要

The earthquake input needed in a shake table test for seismic qualification of safety related electrical instruments, typicallymounted on electrical cabinets or control panels, is defined in terms of incabinet response spectrum. This paper presents acomputer program INCABS for calculating the dynamic properties of the significant cabinet modes and the incabinetresponse spectra. INCABS was developed to implement a new Ritz-vector approach developed by the authors. It takes onlylimited information on cabinet properties and evaluates realistic incabinet spectrum at an instrument location. INCABS canaccount for actual bending as well as rotational constraints imparted by supporting structural members such as stiffeners. Ituses simple equations to account for the flexibility of mounting arrangement at the cabinet base. It can also be applied tobench board type cabinets in which instruments are mounted on plates or frames that are inclined to the global axes as well asto frames in which parallel frame members vibrate in different shapes. INCABS can be used both as a stand-alone programand as a web-based tool. The accuracy of the program is evaluated by comparison of results for actual cabinets with thecorresponding results obtained from detailed finite element analyses.