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In this research the tail equivalent linearization method(TELM) has been extended to study structures with degrading materials. The responses of such structures to excitations are non-stationary, even if the excitations are stationary. Non-stationary behavior of the system cannot be considered by conventional TELM. Applying the conventional TELM, the only distinction in the design point excitation for two stationary excitations with different durations is in the addition of a zero value part at the beginning of the design point of the longer excitation. This means that the failure probability is the same for the non-stationary systems under excitations with different durations. Therefore, this solution cannot be correct. In this study, in using TELM for systems with degrading materials, hysteretic energy is replaced by average hysteretic energy, calculated by averaging the obtained hysteretic energy of the structure subjected to a few random sample load realization. In this way, the degradation parameters under design point coincide with those under sample load realizations. Since the average of the hysteretic energy is converges very fast, the modified TELM only requires about tens to hundreds solutions of the response in addition to the ordinary calculations of conventional TELM. 相似文献
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Mohammad Reza Falamarz-Sheikhabadi Mohsen Ghafory-Ashtiany 《Journal of Seismology》2012,16(4):815-827
The paper addresses the issue of researching into the engineering characteristics of rotational strong ground motion components and rotational effects in structural response. In this regard, at first, the acceleration response spectra of rotational components are estimated in terms of translational ones. Next, new methods in order to consider the effects of rotational components in seismic design codes are presented by determining the effective structural parameters in the rotational loading of structures due only to the earthquake rotational components. Numerical results show that according to the frequency content of rotational components, the contribution of the rocking components to the seismic excitation of short period structures can never be ignored. During strong earthquakes, these rotational motions may lead to the unexpected overturning or local structural damages for the low-rise multi-story buildings located on soft soil. The arrangement of lateral-load resisting system in the plan, period, and aspect ratio of the system can severely change the seismic loading of wide symmetric buildings under the earthquake torsional component. 相似文献
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Motamed Hooman Ghafory-Ashtiany Mohsen Amini-Hosseini Kambod Mansouri Babak Khazai Bijan 《Natural Hazards》2020,101(1):87-102
Natural Hazards - Analysis of the run-out of landslides is essential and vital for disaster mitigation. However, accurate run-out analysis is difficult because of the uncertainty of earthquake... 相似文献
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Karim Zadeh Zarin Ghafory-Ashtiany Mohsen Kalantari Afshin Shokuhirad Sahar 《Bulletin of Earthquake Engineering》2022,20(11):5905-5942
Bulletin of Earthquake Engineering - One of the main components for developing regional seismic risk models is the fragility functions of common building types. Due to the differences between the... 相似文献
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The paper examines the effect on the structural response of the inevitable correlation which exists between the six earthquake components acting along a set of structural axes. The rotational components are expressed in terms of the spatial derivatives of the translational components. For the calculation of response, modal analysis is employed so that ground response spectra can also be used as seismic input. A methodology is developed to obtain the maximum mean square response which can occur in a structure, irrespective of its orientation with respect to the impinging seismic waves. The application of this methodology for the calculation of design response is advocated, especially for asymmetric structures. For the assumed model of seismic wave motion, the numerical results show a significant contribution to the response from the rotational components. This contribution is, however, expected to be reduced by structural foundation averaging and interaction effects. Further studies with more complete models of seismic wave motions, and their interaction with structural foundations, are thus warranted for a realistic evaluation and characterization of the rotational inputs for design purposes. 相似文献
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The step-by-step modal time history integration methods are developed for dynamic analysis of non-classically damped linear structures subjected to earthquake-induced ground motions. Both the mode displacement and mode acceleration-based algorithms are presented for the calculation of member and acceleration responses. The complex-valued eigenvectors are used to effect the modal decoupling of the equations of motion. However, the recursive step-by-step algorithms are still in terms of real quantities. The numerical results for the acceleration response and floor response spectra, obtained with these approaches, are presented. The mode acceleration approach is observed to be decidedly better than the mode displacement approach in as much as it alleviates the so-called missing mass effect, caused by the truncation of modes, very effectively. The utilization of the mode acceleration-based algorithms is, thus, recommended in all dynamic analyses for earthquake-induced ground motions. 相似文献
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Post-Bam earthquake: recovery and reconstruction 总被引：3，自引：1，他引：2
This paper gives a brief explanation of the earthquake in Bam. It also reports on the rescue and relief operations, including
the construction of emergency shelters and temporary housing, and on the country’s plan for the reconstruction of the city,
which includes debris removal, the rebuilding of rural and urban residential and commercial units, the reconstruction of state
and public buildings and public facilities such as schools, rural and urban water aqueducts and grids, the construction of
a sewage system, power network and telecommunication system, the provision of water to orchards and farmlands, the renovation
of industries and the revival of the cultural heritage, particularly the historical Bam citadel, among others. We also report
briefly on the effect of the Bam earthquake on the Iran Earthquake Risk Reduction Strategy and actions.
相似文献
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