Analytical Study of Seismic Progressive Collapse in a Steel Moment Frame Building

2012 ◽  
Vol 446-449 ◽  
pp. 102-108
Author(s):  
Niloofar Parsaeifard ◽  
Fariborz Nateghi Alahi
Keyword(s):  
Progressive Collapse ◽  
Three Dimensional ◽  
The Other ◽  
Nonlinear Static Analysis ◽  
Collapse Mechanism ◽  
Three Dimensional Model ◽  
Steel Moment Frame ◽  
Collapse Potential ◽  
Frame Building ◽  
Ductile Behavior

Progressive collapse is defined as total or remarkable partial collapse of structure following the damage occurred at a small portion of the structure. In most cases, the study is focused on progressive collapse of structures due to explosion, vehicle impact, fire and other man-made hazards; with less attention on progressive collapse mechanism of structure due to earthquake. Although the post earthquake inspections show that structural elements, mostly columns in the corner of the plan, can be severely damaged during earthquake. If neighboring columns are not properly designed to resist and redistribute the additional gravity load that is imposed by the column loss, partial collapse of the structure will occur; which would lead to progressive collapse of the structure. In this regard, progressive collapse potential of a moment resisting steel building is investigated via analytical procedure under earthquake action. In this research, a corner-column of the building was weakened intentionally to navigate the damage toward a certain part of the structure. Then, nonlinear static analysis is carried out on the three dimensional model of the building and the total behavior of the structure is studied. The results indicate that after the failure of the corner-column, the lateral resistance of the frame in which the removed (failed) column was located decreases, and the failure of the other columns occurs. Large plastic deformations and the failure of the other members could cause progressive collapse in the whole structure and the expected ductile behavior of the structure would not be observed.

scholarly journals Epistemicism and modality

2016 ◽  
Vol 46 (4-5) ◽  
pp. 803-835 ◽  
Author(s):  
Juhani Yli-Vakkuri
Keyword(s):  
Model Theory ◽  
Three Dimensional ◽  
The Other ◽  
Object Language ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Metaphysical Necessity ◽  
Actuality Operator

AbstractWhat kind of semantics should someone who accepts the epistemicist theory of vagueness defended in Timothy Williamson's Vagueness (1994) give a definiteness operator? To impose some interesting constraints on acceptable answers to this question, I will assume that the object language also contains a metaphysical necessity operator and a metaphysical actuality operator. I will suggest that the answer is to be found by working within a three-dimensional model theory. I will provide sketches of two ways of extracting an epistemicist semantics from that model theory, one of which I will find to be more plausible than the other.

Nonlinear Static Analysis for Progressive Collapse Potential of RC Building

2011 ◽  
Vol 94-96 ◽  
pp. 146-152 ◽  
Author(s):  
Tie Cheng Wang ◽  
Zhi Ping Li
Keyword(s):  
Static Analysis ◽  
Progressive Failure ◽  
Progressive Collapse ◽  
Frame Structure ◽  
Nonlinear Static Analysis ◽  
Collapse Potential ◽  
Concrete Frame ◽  
Rc Building ◽  
Edge Span ◽  
Nonlinear Static

In this study, the progressive collapse potential of a 10-storey concrete frame structure was investigated using nonlinear static analysis. 15 different cases were considered and their performances were compared with each other. From the nonlinear static analysis results, most of longitudinal beams in upper floors and slabs above the failure column would collapse as the results of removing an exterior column, no beams and slabs would collapse when an interior column at ground floor was removed, and only the short-span beams in superstructure would collapse when an interior column in upper floors was removed. Tie force reinforcement along floors and beams of edge span can be used to avoid the progressive failure of floors, after failure of particular column.

Intensity Change of Binary Tropical Cyclones in an Idealized Three-Dimensional Model

2020 ◽  
Author(s):  
Haoyan Liu
Keyword(s):  
Tropical Cyclones ◽  
Three Dimensional ◽  
Vertical Wind Shear ◽  
Separation Distance ◽  
Horizontal Resolution ◽  
The Other ◽  
Intensity Change ◽  
Asymmetric Structure ◽  
Three Dimensional Model ◽  
Initial Separation

<p>This study investigates the intensity change of binary tropical cyclones (TCs) under the influence of their mutual interaction in an idealized three-dimensional full-physics numerical model with a finest horizontal resolution of 3 km. The two identical TCs merge within the initial separation distance of 600 km.</p><p>Due to the interaction between binary TCs, the intensity evolution presents two weakening stages and an unchanged stage between them. Such intensity change of each one in binary TCs is correlated to the upper-layer vertical wind shear (VWS) caused by the other TC. During the first stage, the upper-layer anticyclone (ULA) of one TC results in the upper-layer VWS and ventilates the warm core of the other TC above the outflow layer, which causes the intensity of the binary TCs decreasing. During the second stage, as the ULA stretches downward and outward, the upper-layer VWS changes to the opposite direction, along with the intensity decreasing first and then increasing. Meanwhile, the intensity of the binary TCs stays unchanged. In the last stage, the binary TCs weaken again as the upper-layer VWS increases to some extent except the merging cases. When the two TCs approach each other before merging, the upper-layer VWS in one TC is almost caused by the upper-layer cyclone and outflow of the other, which induces highly asymmetric structure and weakens the vortex. In addition, the horizontal size of the ULA quantified by the Rossby radius of deformation seems to be a critical separation distance of binary TCs, exceeding which the VWS is small enough to influence the intensity.</p>

Computational simulation of steel moment frame to resist progressive collapse in fire

2016 ◽  
Vol 7 (4) ◽  
pp. 286-305 ◽  
Author(s):  
Ha Nguyen ◽  
Ann E. Jeffers ◽  
Venkatesh Kodur
Keyword(s):  
Experimental Data ◽  
Large Scale ◽  
Progressive Collapse ◽  
Computational Simulation ◽  
Three Dimensional ◽  
Fe Model ◽  
Moment Frame ◽  
Steel Moment Frame ◽  
Fixed Temperature ◽  
Content Type

Purpose This paper aims to address a need for improving the structural resilience to multi-hazard threats including fire and progressive collapse caused by the loss of a column. Design/methodology/approach The focus is on a steel moment frame that uses welded-unreinforced flange-bolted web connections between the beams and columns. A three-dimensional finite element (FE) model was created in ABAQUS with temperature-dependent properties for steel based on the Eurocode. The model was validated against experimental data at ambient and elevated temperature. Findings The failure mechanisms in the FE model were consistent with experimental observations. Two scenarios were considered: fixed load with increasing temperature (i.e. simulating column failure prior to fire) and fixed temperature with increasing load (i.e. simulating column failure during fire). Originality/value A macro element (or component-based) model was also introduced and validated against the FE model and the experimental data, offering the possibility of analyzing large-scale structural systems with reasonable accuracy and improved computational efficiency.

A New Cylinder Profile of Double-Action Sliding Vane Compressor and its Three Dimensional Model Based on SolidWorks

2011 ◽  
Vol 105-107 ◽  
pp. 2263-2266
Author(s):  
Chun Hui Lu
Keyword(s):  
Three Dimensional ◽  
The Other ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Working Chamber ◽  
Model Based ◽  
Chamber Volume ◽  
Profile Equation ◽  
Compressor Design

Profile is the most important base in double-action compressor design. Different cylinder profile decides different working chamber volume in double-action sliding vane compressor. Five equations of cylinder profile were researched by calculating the working chamber volumes and a new cylinder profile equation of double-action sliding vane compressor was composed to get larger chamber. In same condition with the other equations, the working chamber volume of new profile is bigger than the old profiles over 20 percent while it has no change in the moving and friction characters. And a three dimensional model based on SolidWorks of a new profile was done. Finally, it was assembled successfully in computer to check the design.

scholarly journals A slip law for hard-bedded glaciers derived from observed bed topography

2021 ◽  
Vol 7 (20) ◽  
pp. eabe7798
Author(s):  
Christian Helanow ◽  
Neal R. Iverson ◽  
Jacob B. Woodard ◽  
Lucas K. Zoet
Keyword(s):  
Sea Level ◽  
Slip Velocity ◽  
Water Pressure ◽  
Three Dimensional ◽  
Ice Sheet ◽  
The Other ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Bed Topography ◽  
Process Based Models

Ice-sheet responses to climate warming and associated sea-level rise depend sensitively on the form of the slip law that relates drag at the beds of glaciers to their slip velocity and basal water pressure. Process-based models of glacier slip over idealized, hard (rigid) beds with water-filled cavities yield slip laws in which drag decreases with increasing slip velocity or water pressure (rate-weakening drag). We present results of a process-based, three-dimensional model of glacier slip applied to measured bed topographies. We find that consideration of actual glacier beds eliminates or makes insignificant rate-weakening drag, thereby uniting process-based models of slip with some ice-sheet model parameterizations. Computed slip laws have the same form as those indicated by experiments with ice dragged over deformable till, the other common bed condition. Thus, these results may point to a universal slip law that would simplify and improve estimations of glacier discharges to the oceans.

Numerical Analysis for Progressive Collapse and Protection of Underground Structure under Internal Blast Load

2012 ◽  
Vol 226-228 ◽  
pp. 1039-1044
Author(s):  
Li Tian ◽  
Qi Wang
Keyword(s):  
Progressive Collapse ◽  
Underground Structure ◽  
Three Dimensional ◽  
Simulation Method ◽  
Blast Load ◽  
Three Dimensional Model ◽  
Collapse Resistance ◽  
Explicit Dynamic ◽  
Fluid Interaction ◽  
Middle Column

Dynamic response of an underground structure with the protection of foamed aluminum under internal blast load, compared with that without any protection, has been investigated numerically in this paper. The three dimensional model of the two-storey and two-span underground structure covered with soil around was built with the explicit dynamic analytical software LS-DYNA. The three-stage simulation method （TSSM） is proposed. And the middle column of the structure is covered with foamed aluminum which provides a better protection for the column under the blast load. The solid-fluid interaction algorithm, the erosion algorithm and the stress initialization method are employed in the calculation. It is found that, under the protection of foamed aluminum the collapse resistance of the structure has been improved greatly compared with the structure without any protection.

scholarly journals Pastoraal bidden als samenspraak

2021 ◽  
Vol 64 (1) ◽  
pp. 26-43
Author(s):  
R.J. De Vries
Keyword(s):  
Qualitative Research ◽  
The Netherlands ◽  
Pastoral Care ◽  
Three Dimensional ◽  
The Other ◽  
Practical Significance ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Protestant Church

Presenting the results of a qualitative research on the practice of prayer in pastoral care, this article discusses the questions which most interest ministers in the Protestant Church in the Netherlands. Dialogue − between the pastor and the other, and between the conversation partners and God − is a key issue. The article presents a three-dimensional model of this dialogue and elaborates a theology of pastoral prayer as spiritual fellowship. It then argues that in pastoral care, ministers, with their conversation partners, should pay more attention to the theological quality and the practical significance of dialogue on praying together.

scholarly journals A Survey of Stakeholder Visualization Approaches

2016 ◽  
Vol 2 (1,2) ◽  
Author(s):  
Martin Cenek ◽  
Ondřej Částek
Keyword(s):  
Three Dimensional ◽  
The Other ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Advantages And Disadvantages ◽  
The Third ◽  
Model Based ◽  
The Relationship ◽  
Over Time

The aim of this paper is to present an overview of studies for the representation/visualization of stakeholders with a proposal of our own method of visualization. The following text examines the existing representational methods and at the same time critically evaluates their advantages and disadvantages. In addition, our own proposed approach is also presented.The need to develop visualization methods for use in the concept of stakeholders has been accepted by researchers, and it is possible to encounter number of various alternatives which have been applied more or less successfully. The shared weakness of the majority of the models is that they only represent two main attributes simultaneously. When such models do contain three variables, then the third one is only a complementary aspect of the relationship compared to the two dominant attributes.Our proposed visualisation model based on three Mitchell´s (1997) stakeholder attributes should overcome the before mentioned disadvantage. Also, it takes into account the development over time in accordance with the dynamic of the relationships with the stakeholders. Therefore, the proposed three-dimensional model meets these needs and simultaneously removes the shortcomings of the other models, which are identified in our overview presented in this paper.

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