Dynamic amplification of electrical cabinets. [1--100Hz]
BNL has studied the dynamic amplification of electrical equipment by use of existing test data. The study provides a relationship between the input motion at the base of an equipment and the output motion at a device location in the cabinet. The methodology used for analysis of the seismic test data, the results obtained from the analysis and the influence of various parameters in controlling the amplification factors are discussed in this report. The dynamic amplification factor at a location in the equipment is defined as the ratio of the spectral accelerations of the amplified motion at the particular location and the input motion at the base. The amplification factors are computed for various frequencies due to excitation in the front-to-back direction and the results are presented as amplification spectra in the frequency range 1--100Hz. The influence of various parameters in controlling the dynamic amplification factors has been studied. At low frequencies (e.g., < 16Hz), the amplification has a tendency to increase with the elevation in the cabinet and usually reaches a maximum value somewhere above the mid-height. At high frequencies (e.g., >16Hz), the amplification factors vary widely and may be maximum anywhere in the cabinet. Amplification is typically much higher (e.g., two to four times) at high frequencies than at low frequencies. The addition of a local stiffener significantly reduces the amplification value. Since the results of a low level resonance search test are used for qualification purposes (e.g. verifying mathematical model of an equipment), it is recommended that the limitations of the use of low level test results for predicting equipment performance at the qualification or fragility levels be better understood. 4 refs. 21 figs., 7 tabs.
- Research Organization:
- US Nuclear Regulatory Commission (NRC), Washington, DC (United States); Brookhaven National Lab. (BNL), Upton, NY (United States)
- DOE Contract Number:
- AC02-76CH00016
- OSTI ID:
- 6845732
- Report Number(s):
- NUREG/CR-5203; BNL-NUREG-52159; ON: TI88015189
- Resource Relation:
- Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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