Endurance time method

The endurance time (ET) method is a dynamic structural analysis procedure for seismic assessment of structures. In this procedure, an intensifying dynamic excitation is used as the loading function. Endurance time method is a time-history based dynamic analysis procedure. An estimate of the structural response at different equivalent seismic intensity levels is obtained in a single response history analysis. This method has applications in seismic assessment of various structural types and in different areas of earthquake engineering.
The concept of endurance time method.
Endurance time (ET) method is a dynamic structural analysis procedure in which intensifying dynamic excitation is used as the loading function. An estimate of structural response and/or performance at the entire seismic intensity range of interest is obtained in each response history analysis. The concept of endurance time analysis is similar to the exercise test applied in medicine. Similar concept has also been extended to applications in the analysis of offshore platforms under water waves.
Development history.
The basic concepts of the endurance time method were published in 2004. Application in linear seismic analysis appeared in 2007. ET was subsequently extended to nonlinear analysis of single degree of freedom (SDOF) and multi degree of freedom systems. Procedures for multi-component seismic analysis were subsequently developed.
ET excitation functions.
ET excitation functions are generated by using numerical optimization methods. ET excitation functions are publicly available through internet websites. ET excitation functions can be categorized into five generations as follows:
Application areas in earthquake engineering.
Endurance time method has been applied in the following areas of earthquake engineering:
Structural type applications.
ET method has been applied in seismic assessment of the following structural types:
Advantages of ET method.
Major advantages of the endurance time method are as follows:
Limitations of ET method.
Major limitations of the endurance time method are as follows: