SEISMIC VULNERABILITY ASSESSMENT FOR SAN FRANCISCO TEMPLE IN MORELIA, MEXICO

2019 ◽  
Vol 3 (Special Issue on First SACEE'19) ◽  
pp. 207-2016
Author(s):  
Guillermo Martinez ◽  
David Castillo ◽  
José Jara ◽  
Bertha Olmos
Keyword(s):  
San Francisco ◽  
Seismic Vulnerability ◽  
Seismic Analysis ◽  
Three Dimensional ◽  
Middle Part ◽  
Seismic Demands ◽  
Modeling And Analysis ◽  
Seismic Records ◽  
Cracking Pattern ◽  
The Temple

This paper presents a first approximation of the seismic vulnerability of a sixteenth century building which is part of the historical center of Morelia, Mexico. The city was declared World Heritage by United Nations Educational, Scientific and Cultural Organization in 1991. The modeling and analysis of the building was carried out using a three-dimensional elastic tetrahedral finite elements model which was subjected to probabilistic seismic demands with recurrences of 500 yrs and 1000 yrs in addition to real seismic records. The model was able to correctly identify cracking pattern in different parts of the temple due to gravitational forces. High seismic vulnerability of the arched window and the walls of the middle part of the bell tower of the temple was indicated by the seismic analysis of the model.

Strain Rate Effect on Transmission Tower-Line System under Earthquake

2011 ◽  
Vol 243-249 ◽  
pp. 5845-5848
Author(s):  
Wen Ming Wang ◽  
Hong Nan Li ◽  
Guo Huan Liu ◽  
Li Tian
Keyword(s):  
Strain Rate ◽  
Seismic Analysis ◽  
Three Dimensional ◽  
Element Model ◽  
Strain Rate Effect ◽  
Rate Effect ◽  
Transmission Tower ◽  
Base Shear ◽  
Line System ◽  
Seismic Records

Using ABAQUS software, three dimensional finite element model of a transmission tower-line system is created. Nonlinear seismic responses under three seismic records with and without strain rate effect are studied. The results show that the strain rate effect on the transmission tower-line system is more obvious with an increase in intensity of the earthquake. The influence of strain rate on the top displacement and base shear of tower under certain seismic records is unneglectable. Also, it is shown that the strain rate effect on the deformation of wire is prominent. The strain rate effect on the axial force of wire is neglectable. This simple study reveals the importance of considering strain rate effect in seismic analysis for transmission tower-line system.

Seismic and economic performance of a mid-rise cassette structure

2020 ◽  
Vol 23 (16) ◽  
pp. 3541-3554
Author(s):  
Zhi-Peng Chen ◽  
De-Cheng Feng ◽  
Gang Wu ◽  
Ke-Jian Ma
Keyword(s):  
Economic Performance ◽  
Seismic Analysis ◽  
Damage Index ◽  
Three Dimensional ◽  
Frame Structure ◽  
Plastic Behavior ◽  
Story Drift ◽  
Dimensional Finite Element ◽  
Seismic Records ◽  
Three Dimensional Finite Element

In this article, a new structure called cassette structure is presented. A comparative analysis of seismic and economic performance of a cassette structure and a frame structure is conducted. An existing frame office building is selected and redesigned as a cassette structure to compare the performance of the two kinds of structures. Three-dimensional finite element models are built for the two prototype structures, where fiber elements are used to simulate plastic behavior. To assess the advantages fully, seismic analysis and economic analysis are performed. Eighteen Federal Emergency Management Agency recommended seismic records are used, and the roof displacement, story drift ratio, plastic hinges development, and Park–Ang damage index are compared. Furthermore, the material, template, transportation, and assembling costs are calculated based on Chinese quotas, and the overall economic impact is evaluated. In this case, all indexes show that the cassette structure has an obvious advantage over conventional frame structure.

scholarly journals Off-Design Behavior Analysis and Operating Curve Design of Marine Intercooled Gas Turbine

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Nian-kun Ji ◽  
Shu-ying Li ◽  
Zhi-tao Wang ◽  
Ning-bo Zhao
Keyword(s):  
Steady State ◽  
Gas Turbine ◽  
Optimization Design ◽  
Three Dimensional ◽  
Operational Flexibility ◽  
Modeling And Analysis ◽  
Additional Degree ◽  
Performance Space ◽  
Mechanical Constraints ◽  
Steady State Model

The intercooled gas turbine obtained by adopting an indirect heat exchanger into an existing gas turbine is one of the candidates for developing high-power marine power units. To simplify such a strong coupled nonlinear system reasonably, the feasibility and availability of qualifying equivalent effectiveness as the only parameter to evaluate the intercooler behavior are investigated. Regarding equivalent effectiveness as an additional degree of freedom, the steady state model of a marine intercooled gas turbine is developed and its off-design performance is analyzed. With comprehensive considerations given to various phase missions of ships, operational flexibility, mechanical constraints, and thermal constraints, the operating curve of the intercooled gas turbine is optimized based on graphical method in three-dimensional performance space. The resulting operating curve revealed that the control strategy at the steady state conditions for the intercooled gas turbine should be variable cycle control. The necessity of integration optimization design for gas turbine and intercooler is indicated and the modeling and analysis method developed in this paper should be beneficial to it.

A Stochastic Hierarchical Population System: Excitement, Extinction and Transition to Chaos

2021 ◽  
Vol 31 (14) ◽  
Author(s):  
Irina Bashkirtseva ◽  
Tatyana Perevalova ◽  
Lev Ryashko
Keyword(s):  
Mathematical Modeling ◽  
Food Chain ◽  
Analytical Method ◽  
Three Dimensional ◽  
Biological Parameters ◽  
Top Predator ◽  
Population System ◽  
Modeling And Analysis ◽  
Transition To Chaos ◽  
Random Fluctuations

A problem of the mathematical modeling and analysis of noise-induced transformations of complex oscillatory regimes in hierarchical population systems is considered. As a key example, we use a three-dimensional food chain dynamical model of the interacting prey, predator, and top predator. We perform a comparative study of the impacts of random fluctuations on three key biological parameters of prey growth, predator mortality, and the top predator growth. A detailed investigation of the stochastic excitement, noise-induced transition from order to chaos, and various scenarios of extinction is carried out. Constructive abilities of the semi-analytical method of confidence domains in the analysis of the noise-induced extinction are demonstrated.

Conditioned Simulation of Ground-Motion Time Series at Uninstrumented Sites Using Gaussian Process Regression

2021 ◽  
Author(s):  
Aidin Tamhidi ◽  
Nicolas Kuehn ◽  
S. Farid Ghahari ◽  
Arthur J. Rodgers ◽  
Monica D. Kohler ◽  
...  
Keyword(s):  
Time Series ◽  
Gaussian Process ◽  
Ground Motion ◽  
San Francisco ◽  
Earthquake Engineering ◽  
Seismic Analysis ◽  
Ground Motions ◽  
Free Field ◽  
Gaussian Process Regression ◽  
Motion Time

ABSTRACT Ground-motion time series are essential input data in seismic analysis and performance assessment of the built environment. Because instruments to record free-field ground motions are generally sparse, methods are needed to estimate motions at locations with no available ground-motion recording instrumentation. In this study, given a set of observed motions, ground-motion time series at target sites are constructed using a Gaussian process regression (GPR) approach, which treats the real and imaginary parts of the Fourier spectrum as random Gaussian variables. Model training, verification, and applicability studies are carried out using the physics-based simulated ground motions of the 1906 Mw 7.9 San Francisco earthquake and Mw 7.0 Hayward fault scenario earthquake in northern California. The method’s performance is further evaluated using the 2019 Mw 7.1 Ridgecrest earthquake ground motions recorded by the Community Seismic Network stations located in southern California. These evaluations indicate that the trained GPR model is able to adequately estimate the ground-motion time series for frequency ranges that are pertinent for most earthquake engineering applications. The trained GPR model exhibits proper performance in predicting the long-period content of the ground motions as well as directivity pulses.

Taxonomic description and 3D modelling of a new species of myzostomid (Annelida, Myzostomida) associated with black corals from Madagascar

Zootaxa ◽  
2017 ◽  
Vol 4244 (2) ◽  
pp. 277 ◽  
Author(s):  
LUCAS TERRANA ◽  
IGOR EECKHAUT
Keyword(s):  
New Species ◽  
Phylogenetic Analyses ◽  
Three Dimensional ◽  
Close Relation ◽  
Ventral Side ◽  
Middle Part ◽  
The Body ◽  
Taxonomic Description ◽  
Black Corals ◽  
Organ Systems

Eenymeenymyzostoma nigrocorallium n. sp. is the first species of myzostomid worm associated with black corals to be described. Endoparasitic specimens of E. nigrocorallium were found associated with three species of antipatharians on the Great Reef of Toliara. Individuals inhabit the gastrovascular ducts of their hosts and evidence of infestation is, most of the time, not visible externally. Phylogenetic analyses based on 18S rDNA, 16S rDNA and COI data indicate a close relation to Eenymeenymyzostoma cirripedium, the only other species of the genus. The morphology of E. nigrocorallium is very unusual compared to that of the more conventional E. cirripedium. The new species has five pairs of extremely reduced parapodia located on the body margin and no introvert, cirri or lateral organs. Individuals are hermaphroditic, with the male and female gonads both being located dorsally in the trunk. It also has a highly developed parenchymo-muscular layer on the ventral side, and the digestive system lies in the middle part of the trunk. A three-dimensional digital model of this worm’s body plan has been constructed whereby the external morphology and in toto views of the observed organ systems (nervous, digestive and reproductive) can be viewed on-screen: http://doi.org/10.13140/RG.2.2.17911.21923. 

Applicability of Modal Pushover Analysis on Bridges

2011 ◽  
Vol 255-260 ◽  
pp. 806-810
Author(s):  
Biao Wei ◽  
Qing Yuan Zeng ◽  
Wei An Liu
Keyword(s):  
Seismic Analysis ◽  
Pushover Analysis ◽  
Time History ◽  
Seismic Demand ◽  
Seismic Demands ◽  
Modal Pushover Analysis ◽  
History Analysis ◽  
Bridge Structures ◽  
Scope Of Application ◽  
Modal Pushover

Taking one irregular continuous bridge as an example, modal pushover analysis (MPA) has been conducted to judge whether it would be applicable for seismic analysis of irregular bridge structures. The bridge’s seismic demand in the transverse direction has been determined through two different methods, inelastic time history analysis (ITHA) and MPA respectively. The comparison between those two results indicates that MPA would be suitable only for bridges under elastic or slightly damaged state. Finally, some modifications are used to improve the MPA’s scope of application, and the results illustrate that the adapted MPA will be able to estimate bridges’ seismic demands to some extent.

Seismic Vulnerability of Existing RC Buildings and Influence of the Decoupling of the Effective Masonry Panels from the Structural Frames

2012 ◽  
Vol 268-270 ◽  
pp. 646-655
Author(s):  
Fabio de Angelis ◽  
Donato Cancellara
Keyword(s):  
Reinforced Concrete ◽  
Seismic Vulnerability ◽  
Seismic Analysis ◽  
Effective Interaction ◽  
Collapse Mechanism ◽  
Limit States ◽  
Capacity Curves ◽  
Masonry Infills ◽  
N2 Method ◽  
Structural Frame

In the present work we discuss on the seismic vulnerability of reinforced concrete existing buildings. In particular we consider a reinforced concrete building originally designed for only gravitational loads and located in a zone recently defined at seismic risk. According to the Italian seismic code NTC 2008 a displacement based approach is adopted and the N2-method is considered for the nonlinear seismic analysis. In the analysis all the masonry infill panels in effective interaction with the structural frame are considered for the nonlinear modeling of the structure. The influence of the effective masonry infills on the seismic response of the structure is analyzed and it is discussed how the effect of the masonry infills irregularly located within the building can give rise to a worsening of the seismic performance of the structure. It is shown that in the present case a not uniform positioning of the masonry infills within the building can give rise to a fragile structural behavior in the collapse mechanism. Furthermore a comparative analysis is performed by considering both the structure with the effective masonry infills and the bare structural frame. For these two structures a pushover analysis is performed, the relative capacity curves are derived and it is shown that fragile collapse mechanisms can occur depending on the irregular positioning of the effective masonry infills. Accordingly it is discussed how in the present case a decoupling of the effective masonry infills from the structural frame can give rise to a smoother response of the capacity curves. For the examined case of an obsolete building with irregular positioning of the masonry panels, the choice of decoupling the effective masonry panels from the structural frame may facilitate the retrofitting strategies for the achievement of the proper safety factors at the examined limit states.

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