abstract

To answer the question, “What response amplitude is sustained for a duration equal to a specified number of cycles?”, a technique was developed using the response of a single-degree-of-freedom, lightly damped oscillator to generate a spectrum of amplitudes that corresponds to a specific number of cycles. This technique provides a simple approach by which to compare the amplitude sustained for given numbers of cycles as a percentage of the maximum response.

The response as a function of time may consist of one or a very few oscillations of high amplitude followed by many oscillations of lower amplitude. An “effective response” defined in terms of the amplitude sustained for a chosen number of cycles might indicate the severity of the response to a particular earthquake. Preliminary analyses of 12 accelerograms indicate that for oscillators with 5 percent damping and with periods in the range of 0.04 to 4 sec, the mean “effective response” for four cycles lies between 52 to 76 per cent of maximum response.

First Page Preview

First page PDF preview
You do not currently have access to this article.