Predicting probabilistic distribution functions of response parameters using the endurance time method

Abstract

The main objective of this study is the development of endurance time (ET) excitations in order to take structural response uncertainty into account for use in performance-based earthquake engineering. There are several uncertainties in earthquake engineering, including earthquake occurrence, structural response, damage, and loss.In the current research, structural response uncertainty is directly included in the ET method, which is an analysis method used for performing structural behavior assessment under seismic actions. Conventional practice of the ET method does not provide any information about seismic response distribution. Despite the simplicity of the ET method, it is an accurate dynamic analysis approach in which structures are subjected to predesigned intensifying acceleration functions, also known as ET excitation functions (ETEFs). In this study, the ETEF generating procedure is modified in order to include the exceedance probability of structural responses observed at an intensity measure. This proposed method is applied to generate new ETEFs; then they are utilized in assessing distribution responses in three structure case studies. Finally, response distributions obtained by the ET method are compared with incremental dynamic analysis so as to investigate the proposed method efficiency. Results show that response probabilistic distributions that are predicted using the ET method match those obtained by incremental dynamic analysis. KEYWORDS endurance time method, engineering demand parameter, performance-based earthquake engineering, record-to-record variability, seismic response analysis, uncertainty 1 | INTRODUCTIONThe main objective of this study is the development of endurance time (ET) excitations in order to take structural response uncertainty into account for use in performance-based earthquake engineering (PBEE). There are several uncertainties in earthquake engineering, including earthquake occurrence, structural response, damage, and losses. In the current study, structural response uncertainty is directly included in the ET method. The mentioned method is an analysis technique used for performing structural behavior assessment under seismic actions. Traditional practice of the ET method does not provide any information about seismic response distribution. Accounting for uncertainties is an essential need for modern PBEE in evaluating structural system performance.In a promising PBEE methodology developed by the Pacific Earthquake Engineering (PEER) center, uncertainty in different analytical stages is taken into account for determining any facility performances. [1,2] The performance assessment is divided into four analytical stages: probabilistic seismic hazard analysis, structural response assessment, damage analysis, and loss analysis. In PEER framework, the mean annual rate of a decision

The application of endurance time method for optimum seismic design of steel moment-resisting frames using the uniform deformation theory

“…In addition, its results are in good agreement with other conventional seismic analysis methods, which is shown in separate studies [30], [37]. Efforts have been made to optimally generate endurance time excitations using wavelet theory [38], particle swarm optimization method [39],as well as considering propabilistic distribution parameters [40]. A large amount of effort has been put in for application of endurance time method for performance-based design or other structural analyzes, for example, to investigate the interaction of moment frame and shear wall [41].…”

Efficient seismic risk assessment of irregular steel‐framed buildings through endurance time analysis of consistent fish‐bone model

“…Considering a normal statistical distribution for structural responses and having their median and 84th percentile at each intensity level, the dispersion of response parameters at each intensity level can be achieved. More details on the ETA40lc and ETA40lc16p acceleration functions can be found in Mashayekhi et al [69,78] F I G U R E 1 0 Correlation between time in the median of the ETA40lc response curve and normalized spectral acceleration at different fundamental periods…”

“…Using judgment-based dispersion is the initial idea for applying the ET method to probabilistic analyses. Afterward, a study was conducted by Mashayekhi et al [69] in 2019 to directly determine the dispersion of structural response using the ET analysis method. They developed a new ET acceleration function, called ETA40lc16p, for probabilistic applications that can determine the response corresponding to the exceedance probability of 16% (or 84th percentile) with a few (one to three) additional NLTHAs.…”

“…They developed a new ET acceleration function, called ETA40lc16p, for probabilistic applications that can determine the response corresponding to the exceedance probability of 16% (or 84th percentile) with a few (one to three) additional NLTHAs. Moreover, in this study, a new approach is proposed using the concepts presented in Mashayekhi et al [69] that is capable of determining the dispersion of structural response at different seismic intensity levels without performing any additional dynamic analyses.…”

Determining the Critical Intensity for Crack Initiation in Concrete Arch Dams by Endurance Time Method

“…This method was inspired from exercise test in medicine [11]. In the ET method, structures are subjected to predesigned intensifying acceleration functions called endurance time excitation functions (ETEF).…”