• Title/Summary/Keyword: response behavior

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A dominant vibration mode-based scalar ground motion intensity measure for single-layer reticulated domes

  • Zhong, Jie;Zhi, Xudong;Fan, Feng
    • Earthquakes and Structures
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    • v.11 no.2
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    • pp.245-264
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    • 2016
  • A suitable ground motion intensity measure (IM) plays a crucial role in the seismic performance assessment of a structure. In this paper, we introduce a scalar IM for use in evaluating the seismic response of single-layer reticulated domes. This IM is defined as the weighted geometric mean of the spectral acceleration ordinates at the periods of the dominant vibration modes of the structure considered, and the modal strain energy ratio of each dominant vibration mode is the corresponding weight. Its applicability and superiority to 11 other existing IMs are firstly investigated in terms of correlation with the nonlinear seismic response, efficiency and sufficiency using the results of incremental dynamic analyses which are performed for a typical single-layer reticulated dome. The hazard computability of this newly proposed IM is also briefly discussed and illustrated. A conclusion is drawn that this dominant vibration mode-based scalar IM has the characteristics of strong correlation, high efficiency, good sufficiency as well as hazard computability, and thereby is appropriate for use in the prediction of seismic response of single-layer reticulated domes.

Seismic response analysis of embankment dams under decomposed earthquakes

  • Nasiri, Fatemeh;Javdanian, Hamed;Heidari, Ali
    • Geomechanics and Engineering
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    • v.21 no.1
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    • pp.35-51
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    • 2020
  • In this study, the seismic response analysis of embankment dams was investigated through numerical modeling. The seismic behavior of dams under main earthquake records and wavelet-based records were studied. Earthquake records were decomposed using de-noising method (DNM) and down-sampling method (DSM) up to five levels. In decomposition process, low and high frequencies of the main earthquake record were separated into two signals. Acceleration response, spectral acceleration, and Fourier amplitude spectrum at the crest of embankment dams under different decomposition levels were evaluated. The seismic behavior under main and decomposed earthquake records was compared. The results indicate an acceptable agreement between the seismic responses of embankment dams under wavelet-based decomposed records and main earthquake motions. Dynamic analyses show that the DNM-based decomposed earthquake records have a better performance compared to DSM-based records. DNM-based records up to level 4 and DSM-based records up to level 2 have a high accuracy in assessment of seismic behavior of embankment dams. The periods corresponding to the maximum values of acceleration spectra and the frequencies corresponding to the maximum values of Fourier amplitude spectra of embankment dam crest under main and decomposed records are in good agreement. The results demonstrate that the main earthquake records can be replaced by wavelet-based decomposed records in seismic analysis of embankment dams.

A Study on environmental elements in positive place according to the behavioral characteristics by users -focusing on circulation in environmental space by physically handicapped in Korea- (사용자 특성에 적합한 적극적 장소의 물리적 환경요소분석에 관한 연구 -우리나라 지체 장애자의 이동환경실태를 중심으로-)

  • 김혜원
    • Korean Institute of Interior Design Journal
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    • no.9
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    • pp.108-115
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    • 1996
  • The relationship between users and physical elements of environmental gives a space special characteristics. The Environment Probabilitism by Altman shows that behavior and environment, both response, effect each other construct their characteristics. People can choose their response consciously or unconsciously during their walking , sitting, standing, talking in their environment. Designing a good place can lead people to the goal that they want and designer intend to get, A good place well designed as an positive place is organised with 3 points(1) User's behavior (2) physical elements in environment (3) meanings produced between behavior and physical elements. In this study the importance of physical elements are focused on. In the place where we can have permeability, variety , legibility, robutness, visual appropriateness, richness, personalisation physically , these characteristics will encourage people to have strong motivation and to choose the most active way . From this perspective the circulation of physically handicapped persons is analyzed into their behavioral environment and their behavioral response. The analysis shows the handicapped in our situation has no environmental right for a man itself ,even they have no street to walk safely. And their response to the environment was very negative. Basically the elements from exterior space to interior space should be guaranteed for everyday according to their behavioral characteristics include handicapped. From this study the result shows that the needs of a person should be considered and accepted as an important design problem for improvement our environment.

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Effect of connection modeling on the seismic response of steel braced non-moment resisting frames

  • Bagheri, Saman;Tabrizi, Navid Vafi
    • Structural Engineering and Mechanics
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    • v.68 no.5
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    • pp.591-601
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    • 2018
  • Non-moment beam-to-column connections, which are usually referred to as simple or shear connections, are typically designed to carry only gravity loads in the form of vertical shears. Although in the analysis of structures these connections are usually assumed to be pinned, they may provide a small amount of rotational stiffness due to the typical connection details. This paper investigates the effects of this small rotational restraint of simple beam-to-column connections on the behavior and seismic response of steel braced non-moment resisting frames. Two types of commonly used simple connections with bolted angles, i.e., the Double Web angle Connection (DWC) and Unstiffened Seat angle Connection (USC) are considered for this purpose. In addition to the pinned condition - as a simplified representation of these connections - more accurate semi-rigid models are established and then applied to some frame models subjected to nonlinear pushover and nonlinear time history analyses. Although the use of bracing elements generally reduces the sensitivity of the global structural response to the behavior of connections, the obtained results indicate considerable effects on the local responses. Namely, our results show that consideration of the real behavior of connections is essential in designing the column elements where the pin-connection assumption significantly underestimates design of outer columns of upper stories.

Sensitivity analysis of mass ratio effect on settlement and seismic response of shallow foundation using numerical simulation

  • Kil-Wan Ko;Jeong-Gon Ha;Jinsun Lee;Gye-Chun Cho
    • Geomechanics and Engineering
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    • v.34 no.6
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    • pp.649-664
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    • 2023
  • Structural inertial interaction is a representative the effect of dynamic soil-foundation-structure interaction (SFSI), which leads to a relative displacement between soil and foundation, period lengthening, and damping increasing phenomena. However, for a system with a significantly heavy foundation, the dynamic inertia of the foundation influences and interacts with the structural seismic response. The structure-to-foundation mass ratio (MR) quantifies the distribution of mass between the structure and foundation for a structure on a shallow foundation. Although both systems exhibit the same vertical factor of safety (FSv), the MR and corresponding seismic responses attributed to the structure and foundation masses may differ. This study explored the influence of MR on the permanent deformation and seismic response of soil-foundation-structure system considering SFSI via numerical simulations. Given that numerous dimensionless parameters of SFSI described its influence on the structural seismic response, the parameters, except for MR and FSv, were fixed for the sensitivity analysis. The results demonstrated that the foundation inertia of heavier foundations induced more settlement due to sliding behavior of heavily-loaded systems. Moreover, the structural inertia of heavier structures evidently exhibited foundation rocking behavior, which results in a more elongated natural period of the structure for lightly-loaded systems.

A TSK fuzzy model optimization with meta-heuristic algorithms for seismic response prediction of nonlinear steel moment-resisting frames

  • Ebrahim Asadi;Reza Goli Ejlali;Seyyed Arash Mousavi Ghasemi;Siamak Talatahari
    • Structural Engineering and Mechanics
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    • v.90 no.2
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    • pp.189-208
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    • 2024
  • Artificial intelligence is one of the efficient methods that can be developed to simulate nonlinear behavior and predict the response of building structures. In this regard, an adaptive method based on optimization algorithms is used to train the TSK model of the fuzzy inference system to estimate the seismic behavior of building structures based on analytical data. The optimization algorithm is implemented to determine the parameters of the TSK model based on the minimization of prediction error for the training data set. The adaptive training is designed on the feedback of the results of previous time steps, in which three training cases of 2, 5, and 10 previous time steps were used. The training data is collected from the results of nonlinear time history analysis under 100 ground motion records with different seismic properties. Also, 10 records were used to test the inference system. The performance of the proposed inference system is evaluated on two 3 and 20-story models of nonlinear steel moment frame. The results show that the inference system of the TSK model by combining the optimization method is an efficient computational method for predicting the response of nonlinear structures. Meanwhile, the multi-vers optimization (MVO) algorithm is more accurate in determining the optimal parameters of the TSK model. Also, the accuracy of the results increases significantly with increasing the number of previous steps.

Influence of wall flexibility on dynamic response of cantilever retaining walls

  • Cakir, Tufan
    • Structural Engineering and Mechanics
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    • v.49 no.1
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    • pp.1-22
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    • 2014
  • A seismic evaluation is made of the response to horizontal ground shaking of cantilever retaining walls using the finite element model in three dimensional space whose verification is provided analytically through the modal analysis technique in case of the assumptions of fixed base, complete bonding behavior at the wall-soil interface, and elastic behavior of soil. Thanks to the versatility of the finite element model, the retained medium is then idealized as a uniform, elastoplastic stratum of constant thickness and semi-infinite extent in the horizontal direction considering debonding behavior at the interface in order to perform comprehensive soil-structure interaction (SSI) analyses. The parameters varied include the flexibility of the wall, the properties of the soil medium, and the characteristics of the ground motion. Two different finite element models corresponding with flexible and rigid wall configurations are studied for six different soil types under the effects of two different ground motions. The response quantities examined incorporate the lateral displacements of the wall relative to the moving base and the stresses in the wall in all directions. The results show that the wall flexibility and soil properties have a major effect on seismic behavior of cantilever retaining walls and should be considered in design criteria of cantilever walls. Furthermore, the results of the numerical investigations are expected to be useful for the better understanding and the optimization of seismic design of this particular type of retaining structure.

The Seismic Behavior of the Truss-Arch Structure with Lead Rubber Bearing(LRB) (납-고무면진장치가 적용된 트러스-아치 구조물의 지진거동 분서)

  • Shin, Min -Gi;Kim, Gee-Cheol;Kang, Joo-Won
    • Proceeding of KASS Symposium
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    • 2008.05a
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    • pp.133-138
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    • 2008
  • In this study, the seismic behavior of arch structure with lead rubber bearing(LRB) is analyzed. The arch structure is the simplest structure and has the basic dynamic characteristics among large spatial structures. Also, Large spatial structures have large vertical response by horizontal seismic vibration, unlike seismic behavior of normal rahmen structures. When horizontal seismic load is applied to the large spatial structure with isolation systems, the horizontal acceleration response of the large spatial structure is reduced and the vertical seismic response is remarkably reduced.

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Effect of Protection Motivation Factors on Behavioral Intention to Reduce Sodium Intake among University Students in Gyeongnam and Busan (보호동기요인이 나트륨 저감화 관련 행동 의도에 미치는 영향 - 경남·부산 지역 대학생을 중심으로 -)

  • Jang, Soo-Hyun;Yoon, Eunju
    • The Korean Journal of Food And Nutrition
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    • v.29 no.1
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    • pp.104-114
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    • 2016
  • In this study, we investigated protection motivation and behavioral intention to prevent serious illnesses related to excessive sodium intake among the university students in Gyeongnam and Busan. Within the protection motivation theory (PMT) framework, a survey questionnaire was developed to measure participants' perceptions on the severity of and the vulnerability to the threat of serious diseases due to the high sodium intake as well as the effectiveness of preventive measures (response efficacy), and the ability to perform them (self-efficacy) along with their willingness to follow recommendations (behavioral intention). Data was collected in June 2015. Study participants were divided into either low (n=117) or high (n=177) sodium intake behavior groups based on their current behaviors. Exploratory factor analysis was performed to measure construct validity and Cronbach's alpha was calculated to check reliability of measurement items. The high sodium intake behavior group perceived higher vulnerability than the low sodium intake behavior group among four PMT factors. Differences of the other three factors were not significant between the two groups. The results of hierarchical regression analysis indicated that self-efficacy and response efficacy affected behavioral intention of high sodium intake behavior among students. Hence, development of strategies to increase self-efficacy and response efficacy are strongly recommended.

A Study on Influential Factors of Egress Behavior in Respect of the Fire Prevention Manager in the Large-scale Shopping Mall (대규모 판매시설의 방화관리자의 측면에서 본 피난행동 영향요인에 대한 연구)

  • 박재성;윤명오
    • Fire Science and Engineering
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    • v.18 no.3
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    • pp.108-113
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    • 2004
  • Emergency response of fire prevention manager has an effect on decisive emergency exit behavior of customer who is not accustomed to emergency response in a large-scale shopping department on fire. Especially enclosed stairways in a large scale store are usually located in back space where is impossible for customer to access. Therefore, speedy emergency exit inducement by fire prevention manager is needed for the customer's safe egress. The object of study is to analyse the factors affecting egress behavior and emergency response of fire prevention manager in respect of fire prevention management.