This series includes technical reports prepared by faculty, students and staff who are associated with the John A. Blume Earthquake Engineering Center at Stanford University. While the primary focus of Blume Center is earthquake engineering, many of the reports in this series encompass broader topics in structural engineering and materials, computational mechanics, geomechanics, structural health monitoring, and engineering life-cycle risk assessment. Each report includes acknowledgments of the specific sponsors for the report and underlying research. In addition to providing research support, the Blume Center provides administrative support for maintaining and disseminating the technical reports. For more information about the Blume Center and its activities, see https://blume.stanford.edu.
The increasing need for a better understanding of the structural response to earthquake ground motion, has led to several structural analysis approaches. Among these, the equivalent static force approach and the response spectrum approach, although simple in concept and easy to implement, are known for not being accurate enough, especially if used for the design of very important and complex structures.
To account for the nonlinear behavior of structures, the only reliable and accurate method is the so-called "time history" approach. In this method, a complete acceleration-time history of the earthquake record is used as an input to a structural model. The structural model is assumed to behave non-linearly beyond the elastic limit. A finite-element (two- or three- dimensional) soil-structure model is usually developed for this purpose. The response is obtained by numerical integration. Even though this method provides a sufficiently sophisticated and accurate model of the soil- structural system, the input earthquake time history has considerable uncertainty. Therefore many researchers have developed analytical as well as numerical methods to simulate the earthquake time histories. Such models help to better understand the seismic phenomenon by itself and also give structural designers an option to evaluate the possible non-linear response of their structures due to a family of simulated earthquakes.
Several stationary and non-stationary models for earthquake simulation have been proposed (Cornell, 1964; Housner, 1964; Jennings, 1969; Ipek, 1980). It is generally recognized that due to the transient nature of the seismic input, a non-stationary simulation is far more reasonable, especially if one is dealing with non-linear structural behavior, which is the case for strong ground motions.
This program (Tilliouine, 1982) uses the concept of a physical spectrum (Mark, 1970). It can generate an ensemble of synthetic earthquakes having prescribed non-stationarities, both in the amplitude and frequency domains.
Tilliouine, B., Azevedo, J. and Shah, H.C.. (1984). A Computer Program for Nonstationary Analysis and Simulation of Stong Motion Earthquake Records. John A. Blume Earthquake Engineering Center Technical Report 63. Stanford Digital Repository. Available at: http://purl.stanford.edu/sq079jy9662
User agrees that, where applicable, content will not be used to identify or to otherwise infringe the privacy or confidentiality rights of individuals. Content distributed via the Stanford Digital Repository may be subject to additional license and use restrictions applied by the depositor.