scholarly journals Effect of the Distribution of Mass and Structural Member Discretization on the Seismic Response of Steel Buildings

2022 ◽  
Vol 12 (1) ◽  
pp. 433
Author(s):  
Federico Valenzuela-Beltrán ◽  
Mario D. Llanes-Tizoc ◽  
Edén Bojórquez ◽  
Juan Bojórquez ◽  
Robespierre Chávez ◽  
...  
Keyword(s):  
Structural Model ◽  
Numerical Study ◽  
Mass Matrix ◽  
Structural Modeling ◽  
Seismic Intensity ◽  
Steel Buildings ◽  
Moment Frames ◽  
Axial Loads ◽  
Study Results ◽  
Mdof Systems

The response of steel moment frames is estimated by first considering that the mass matrix is the concentrated type (ML) and then consistent type (MC). The effect of considering more than one element per beam is also evaluated. Low-, mid- and high-rise frames, modeled as complex-2D-MDOF systems, are used in the numerical study. Results indicate that if ML is used, depending upon the response parameter under consideration, the structural model, the seismic intensity and the structural location, the response can be significantly overestimated, precisely calculated, or significantly underestimated. Axial loads at columns, on an average basis, are significantly overestimated (up to 60%), while lateral drifts and flexural moments at beams are precisely calculated. Inter-story shears and flexural moments at columns, on average, are underestimated by up to 15% and 35%, respectively; however, underestimations of up to 60% can be seen for some individual strong motions. Similarly, if just one element per beam is used in the structural modeling, inter-story shears and axial loads on columns are overestimated, on average, by up to 21% and 95%, respectively, while the lateral drifts are precisely calculated. Flexural moments at columns and beams can be considerably underestimated (on average up to 14% and 35%, respectively), but underestimations larger than 50% can be seen for some individual cases. Hence, there is no error in terms of lateral drifts if ML or one element per beam is used, but significant errors can be introduced in the design due to the overestimation and underestimation of the design forces. It is strongly suggested to use MC and at least two elements per beam in the structural modeling.

Amplified Seismic Loads in Steel Moment Frames

2016 ◽  
Vol 847 ◽  
pp. 222-232
Author(s):  
Bora Aksar ◽  
Selcuk Dogru ◽  
Bulent Akbas ◽  
Jay Shen ◽  
Onur Seker ◽  
...  
Keyword(s):  
Lateral Displacement ◽  
Ground Motions ◽  
Time History ◽  
Load Level ◽  
Steel Buildings ◽  
Moment Frames ◽  
Axial Loads ◽  
Steel Moment Resisting Frames ◽  
Moment Resisting Frames ◽  
Moment Resisting

This study focuses on exploring the seismic axial loads for columns in steel moment resisting frames (SMRFs) under strong ground motions. For this purpose, the increases in axial loads are investigated at the maximum lateral load level and the corresponding lateral displacement. The results are presented in terms of maximum amplification factors (Ω0) of all frame columns under the selected ground motions and axial load-moment levels in columns. four typical steel moment resisting frames representing typical low, medium and high rise steel buildings are designed based on the seismic design requirement in ASCE 7-10 and AISC 341-10 . An ensemble of ground motions range from moderate to severe are selected to identify the seismic response of each frames. Two sets of ground motions corresponding to 10% and 2% probability of exceedance are used in nonlinear dynamic time history analyses.

Structural Modeling of Institute of Entrepreneurship in Russia

2019 ◽  
pp. 34-48
Author(s):  
Svetlana L. Sazanova
Keyword(s):  
Global Economy ◽  
Structural Model ◽  
Institutional Environment ◽  
Small And Medium Enterprises ◽  
Structural Modeling ◽  
Entrepreneurial Activity ◽  
Pattern Modeling ◽  
Medium Enterprises ◽  
The Impact ◽  
The Relationship

Entrepreneurship plays an important role in the modern global economy; the share of products of small and medium enterprises in the gross product and exports not only of the developed but also of developing countries is growing. Innovation processes cover all sectors of the economy, and more and more people are involved in entrepreneurial activity, which contributes to the penetration of entrepreneurial thinking and business values in all areas of the socioeconomic life of society. The Institute of Entrepreneurship plays an increasingly prominent role in the institutional environment of socio-economic systems. This actualizes the problem of studying the relationship of the institution of entrepreneurship with the institutions of law, culture, management. This requires a methodology that allows you to explore the impact on the institute of entrepreneurship not only economic, but also non-economic factors. The methodology of the “old” institutionalism possesses such a tool, it is structural modeling (pattern modeling), which allows to explore the diversity of interrelationships of the institution of entrepreneurship with other components of the institutional and economic environment. The article explored the features of the development of the institution of entrepreneurship in Russia, established the relationship between the institution of entrepreneurship, values, motives and incentives for entrepreneurial activity, built a structural model of the institution of entrepreneurship based on the methodology of the old institutionalism (pattern modeling). The structural model of the institution of entrepreneurship reveals the relationship between the institution of entrepreneurship, the values of entrepreneurial activity, its motives and incentives; as well as the relationship between the institution of entrepreneurship with the institutions of governance, cultural and religious institutions, legal institutions and society.

scholarly journals Factors Affecting the Lut Desert Tourism in Iran: Developing an Interpretive-Structural Model

2021 ◽  
Vol 13 (13) ◽  
pp. 7245
Author(s):  
Beniamino Murgante ◽  
Mohammad Eskandari Sani ◽  
Sara Pishgahi ◽  
Moslem Zarghamfard ◽  
Fatemeh Kahaki
Keyword(s):  
Sampling Method ◽  
Structural Model ◽  
Tourism Development ◽  
Cost Effective ◽  
Structural Modeling ◽  
Interpretive Structural Modeling ◽  
Factors Affecting ◽  
Purposive Sampling ◽  
Interpretive Structural Model ◽  
Lut Desert

The Lut desert is one of the largest and most attractive deserts in Iran. The value of desert tourism remains unclear for Iran’s economy and has only recently been taken into consideration by the authorities, although its true national and international value remains unclear. This study was aimed at investigating the factors that influence tourism development in the Lut desert. Data collected through the purposive sampling method was analyzed using Interpretive Structural Modeling and the MICMAC Analysis. According to the results, cost-effective travel expenses, security, and safety provided in the desert, together with appropriate media advertising and illustration of the Lut desert (branding) are the leading factors that influence tourism in the Lut desert in Iran. This paper highlighted the importance of desert tourism, especially in this region.

A Numerical Study of Turbulent Boundary Layer Flow Over a Flat Surface With a Single Dimple

2000 ◽  
Author(s):  
Mark E. Kithcart ◽  
David E. Klett
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Boundary Layer Flow ◽  
Flat Surface ◽  
Numerical Study ◽  
Heat Transfer Augmentation ◽  
Study Results ◽  
Turbulent Boundary Layer Flow ◽  
Layer Flow

Abstract Turbulent boundary layer flow over a flat surface with a single dimple has been investigated numerically using the FLUENT CFD software package, and compared to an experiment by Ezerskii and Shekhov [1989], which studied the same configuration. The impetus for this work developed as a result of previous studies. Kithcart and Klett [1996], and Afanas’yev and Chudnovskiy [1992], showed that dimpled surfaces enhance heat transfer comparably to surfaces with protrusion roughness elements, but with a much lower drag penalty. However, the actual physical mechanisms involved in this phenomena were only partially known prior this study. Results obtained numerically are in good agreement with the experiment, most notably the confirmation of the existence of a region of enhanced heat transfer created by interaction of the flow with the dimple. In particular, the simulation indicates that heat transfer augmentation is a consequence of the development of a stagnation flow region within the dimple geometry, and the existence of coherent vortical structures which create a periodic flow-field within and immediately downstream of the dimple. This periodicity appears to govern the magnitude of the heat transfer augmentation.

Frequency selective antenna radome based on metal-dielectric gratings and perforated screens

Antennas ◽  
2021 ◽  
Author(s):  
A. O. Kasyanov
Keyword(s):  
Antenna Arrays ◽  
Electromagnetic Compatibility ◽  
Numerical Study ◽  
Numerical Data ◽  
Microwave Antenna ◽  
Frequency Selective Surfaces ◽  
Radio Electronic ◽  
Dielectric Gratings ◽  
Study Results ◽  
Frequency Selective

This article is devoted to the analysis of numerical study results of printed frequency selective surfaces scattering characteristics. It has been shown that these frequency selective surfaces may be used as antenna radomes. Numerical results have been obtained by full-wave simulation of frequency-selective surfaces with dielectric covers. The numerical research results of the scattering characteristics of printed frequency selective surfaces as antenna radomes based on metal-dielectric gratings and thick perforated screens have been presented. A comprehensive numerical study of microwave frequency selective surfaces based on multi-element multilayer printed reflectarrays and thick perforated screens has been carried out. Constructive solutions for metal-dielectric structures in integral design, realizing the functions of frequency selective surfaces, have been found. These solutions are based on performed numerical studies. The problems of constructive implementation of multilayer planar spatially selective as frequency selective surfaces have been considered. These frequency selective surfaces are integrated into radiation systems of modern multi-element printed phased arrays. The problems connected with creation of such arrays have been also considered. The numerical simulation results for frequency selective surfaces based on metal gratings with dielectric covers have been obtained. These results can be used to select the most rational options for the topology of metal-dielectric gratings. Such solutions may be useful for design of multifunctional radomes in microwave antenna systems. Based on the obtained numerical data, the possibilities of using flat gratings as frequency selective surfaces in the composition of antenna radomes have been considered. The spatial frequency-selective structures proposed in this work are performed as multi-planar printed gratings. These gratings are designed to ensure electromagnetic compatibility of closely spaced radio electronic sets. These radio electronic sets operate in close frequency ranges. They contain antenna arrays. These arrays are placed under the antenna radomes.

Analysis of interaction among the barriers to 5S implementation using interpretive structural modeling approach

2017 ◽  
Vol 24 (7) ◽  
pp. 1834-1853 ◽  
Author(s):  
Rajesh Attri ◽  
Bhupender Singh ◽  
Sunil Mehra
Keyword(s):  
Structural Equation ◽  
Structural Model ◽  
Structural Modeling ◽  
Equation Modeling ◽  
Successful Implementation ◽  
Interpretive Structural Modeling ◽  
Content Type ◽  
Modeling Approach ◽  
Manufacturing Organizations ◽  
Top Management Commitment

Purpose The purpose of this paper is to ascertain and analyze the interactions among different barriers of 5S implementation in manufacturing organizations. Design/methodology/approach In this paper, 15 barriers affecting the implementation of 5S in manufacturing organizations have been identified from literature analysis and discussion with academic and industrial experts. Afterwards, identified barriers were validated by using nation-wide questionnaire-based survey. Then, interpretive structural modeling (ISM) approach has been utilized to find out the interaction among the identified barriers in order to develop hierarchy-based model. Findings The research identifies several key barriers which have high driving power and weak dependence power. In this concern, these barriers entail extreme care and handling for successful implementation of 5S. Financial constraints, lack of top management commitment, and no proper vision and mission are found to be the key barriers. Research limitations/implications The developed ISM model is based on experts’ opinion. This developed hierarchy-based model requires further validation by using structural equation modeling approach or by performing detailed case studies. Originality/value In this paper, ISM-based structural model has been recommended for Indian manufacturing organizations, which is a novel exertion in the area of 5S implementation.

scholarly journals Effect of Soil Classification on Seismic Behavior of SMFs considering Soil-Structure Interaction and Near-Field Earthquakes

2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Shahrokh Shahbazi ◽  
Iman Mansouri ◽  
Jong Wan Hu ◽  
Armin Karami
Keyword(s):  
Soil Structure ◽  
Near Field ◽  
Free Field ◽  
Soil Structure Interaction ◽  
Nonlinear Time History Analysis ◽  
Type Ii ◽  
Steel Buildings ◽  
Moment Frames ◽  
Structure Interaction ◽  
Soil Flexibility

Seismic response of a structure is affected by its dynamic properties and soil flexibility does not have an impact on it when the bottom soil of foundation is supposedly frigid, and the soil flexibility is also ignored. Hence, utilizing the results obtained through fixed-base buildings can lead to having an insecure design. Being close to the source of an earthquake production causes the majority of earthquake’s energy to reach the structure as a long-period pulse. Therefore, near-field earthquakes produce many seismic needs so that they force the structure to dissipate output energy by relatively large displacements. Hence, in this paper, the seismic response of 5- and 8-story steel buildings equipped with special moment frames (SMFs) which have been designed based on type-II and III soils (according to the seismic code of Iran-Standard 2800) has been studied. The effects of soil-structure interaction and modeling of the panel zone were considered in all of the two structures. In order to model radiation damping and prevent the reflection of outward propagating dilatational and shear waves back into the model, the vertical and horizontal Lysmer–Kuhlemeyer dashpots as seen in the figures are adopted in the free-field boundary of soil. The selected near- and far-field records were used in the nonlinear time-history analysis, and structure response was compared in both states. The results obtained from the analysis showed that the values for the shear force, displacement, column axial force, and column moment force on type-III soil are greater than the corresponding values on type-II soil; however, it cannot be discussed for drift in general.

Seismic Performance Assessment of Existing Steel Buildings: A Case Study

2018 ◽  
Vol 763 ◽  
pp. 1067-1076 ◽  
Author(s):  
Luigi di Sarno ◽  
Fabrizio Paolacci ◽  
Anastasios G. Sextos
Keyword(s):  
Numerical Study ◽  
Central Italy ◽  
Steel Structures ◽  
Eurocode 8 ◽  
Building Structures ◽  
Steel Buildings ◽  
Seismic Performance Assessment ◽  
Masonry Infills ◽  
Main Shocks

Numerous existing steel framed buildings located in earthquake prone regions world-wide were designed without seismic provisions. Slender beam-columns, as well as non-ductile beam-to-column connections have been employed for multi-storey moment-resisting frames (MRFs) built before the 80’s. Thus, widespread damage due to brittle failure has been commonly observed in the past earthquakes for steel MRFs. A recent post-earthquake survey carried out in the aftermath of the 2016-2017 Central Italy seismic swarm has pointed out that steel structures may survive the shaking caused by several main-shocks and strong aftershocks without collapsing. Inevitably, significant lateral deformations are experienced, and, in turn, non-structural components are severely damaged thus inhibiting the use of the steel building structures. The present papers illustrates the outcomes of a recent preliminary numerical study carried out for the case of a steel MRF building located in Amatrice, Central Italy, which experienced a series of ground motion excitations suffering significant damage to the masonry infills without collapsing. A refined numerical model of the sample structure has been developed on the basis of the data collected on site. Given the lack of design drawings, the structure has been re-designed in compliance with the Italian regulations imposed at the time of construction employing the allowable stress method. The earthquake performance of the case study MRF has been then investigated through advanced nonlinear dynamic analyses and its structural performance has been evaluated according to Eurocode 8-Part 3 for existing buildings. The reliability of the codified approaches has been evaluated and possible improvements emphasized.

scholarly journals Structural Modeling and Analysis of Pregnancy-Associated Glycoprotein-1 of Buffalo (Bubalus bubalis)

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Jerome Andonissamy ◽  
S. K. Singh ◽  
S. K. Agarwal
Keyword(s):  
Protein Structure ◽  
Active Sites ◽  
Structural Model ◽  
Protein Structures ◽  
Structural Modeling ◽  
Bubalus Bubalis ◽  
High Energy ◽  
Docking Studies ◽  
Modeling And Analysis ◽  
Structural Conformity

The present study was conducted to design and analyze the structural model of buffalo pregnancy-associated glycoprotein-1 (PAG-1) using bioinformatics. Structural modeling of the deduced buffalo PAG-1 protein was done using PHYRE, CONSURF servers and its structure was subsequently constructed using MODELLER 9.9 and PyMOL softwares Buffalo PAG-1 structural conformity was analyzed using PROSA, WHATIF, and 3D-PSSM servers. Designed buffalo PAG-1 protein structure on BLAST analysis retrieved protein structures belonging to aspartic proteinase family. Moreover in silico analysis revealed buffalo PAG-1 protein retained bilobed structure with pepstatin-binding clefts near the active sites by docking studies with pepstatin A using PatchDock server. Structural studies revealed that the amino and carboxy terminal containing aspartic residues are highly conserved and buried within the protein structure. Structural conformity studies showed that more than 90% of the residues lie inside favored and allowed regions. It was also deduced that buffalo PAG-1 possesses low and high energy zones with a very low threshold for proteolysis ascertaining the stableness of the buffalo PAG-1 protein structure. This study depicts the structural conformity and stability of buffalo PAG-1 protein.

Design Optimization of Machine Structures Based on Multiphase Structural Modeling of Ideal, Intermediate, and Detailed Models

1990 ◽  
Author(s):  
Masataka Yoshimura
Keyword(s):  
Machine Tool ◽  
Design Optimization ◽  
Structural Model ◽  
Structural Modeling ◽  
Optimization Method ◽  
Ideal Model ◽  
Detailed Model ◽  
Intermediate Model ◽  
The Ideal

Abstract This paper proposes a design optimization method consisting of the multiphase structural modeling of ideal, intermediate, and detailed models for machine structures. In this method, the ideal characteristics are first obtained for a specific ideal model. Then, the detailed designs are determined so that the characteristics in the detailed model are as close to the ideal characteristics as possible. For easily and surely obtaining the final detailed designs, an intermediate model is introduced between the ideal model and the detailed model. This method not only effectively generates optimum detailed designs of machine structures but also brings about an easy realization of the optimum characteristics in practical manufactured machine products. The proposed method is applied to a machine-tool structural model for demonstrating the effectiveness of the method.

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