scholarly journals Seismic Protection of RC Buildings by Polymeric Infill Wall-Frame Interface

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1577
Author(s):  
Ahmet Tugrul Akyildiz ◽  
Alicja Kowalska-Koczwara ◽  
Łukasz Hojdys
Keyword(s):  
Three Dimensional ◽  
Mode Shapes ◽  
Dimensional Structure ◽  
Seismic Loads ◽  
Rc Buildings ◽  
Infill Wall ◽  
Infill Walls ◽  
Rc Frames ◽  
Out Of Plane ◽  
Real Size

This paper is aimed at investigating the usage of flexible joints in masonry infilled walls surrounded by reinforced concrete (RC) frames. For this purpose, a real-size specimen was numerically created and exposed to the seismic loads. In order to evaluate both in-plane and out-of-plane performances of the infill walls, the system was chosen as a box shaped three-dimensional structure. In total, three different one-story constructions, which have single bays in two perpendicular directions, were modeled. The first type is the bare-frame without the infill walls, which was determined as a reference system. The second and third types of buildings are conventional mortar joint and PolyUrethane Flexible Joint (PUFJ) implemented ones, respectively. The influence of these joints on the material level are investigated in detail. Furthermore, general building dynamic characteristics were extracted by means of acceleration and displacement results as well as frequency domain mode shapes. Analyses revealed that PUFJ implementation on such buildings has promising outcomes and helps to sustain structural stability against the detrimental effects of earthquakes.

Progressive Collapse Analysis of Reinforced Concrete Frames with Unreinforced Masonry Infill Walls considering In-Plane/Out-of-Plane Interaction

2015 ◽  
Vol 31 (2) ◽  
pp. 921-943 ◽  
Author(s):  
Khalid M. Mosalam ◽  
Selim Günay
Keyword(s):  
Reinforced Concrete ◽  
Shear Failure ◽  
Progressive Collapse ◽  
Unreinforced Masonry ◽  
Concrete Frames ◽  
Infill Wall ◽  
Infill Walls ◽  
Rc Frames ◽  
Out Of Plane ◽  
Plane Interaction

Reinforced concrete (RC) frames with unreinforced masonry (URM) infill walls are commonly used in seismic regions around the world. It is recognized that many buildings of this type perform poorly during earthquakes. Therefore, proper modeling of the infill walls and their effect on RC frames is essential to evaluate the seismic performance of such buildings and to select adequate retrofit methods. Using damage observations of RC buildings with URM infill walls from recent earthquakes, this paper presents a new approach to consider in-plane/out-of-plane interaction of URM infill walls in progressive collapse simulations. In addition, the infill wall effect to induce shear failure of columns is simulated with a nonlinear shear spring modeling approach. The research endeavor is accompanied by implementation of the developed modeling aspects in the publicly available open-source computational platform OpenSees for immediate access by structural engineers and researchers.

scholarly journals Effects of mortar compressive strength on out of plane response of unreinforced masonry walls

2021 ◽  
Vol 20 (2) ◽  
pp. 371-381
Author(s):  
Atabak Pourmohammad Sorkhab ◽  
◽  
Mesut Küçük ◽  
Ali Sari ◽  
◽  
...  
Keyword(s):  
Energy Dissipation ◽  
Unreinforced Masonry ◽  
Infill Wall ◽  
Infill Walls ◽  
Clay Bricks ◽  
Mortar Strength ◽  
Load Carrying ◽  
Out Of Plane ◽  
Structural Behaviors ◽  
Major Crack

In this study, the out-of-plane response of infill walls that are widely used in Turkey and the surrounding regions were experimentally investigated. Several out-of-plane wall tests were performed in the laboratory, with the walls specimens produced with lateral hollow clay bricks (LHCB) and different mortar qualities. The walls were tested in their out-of-plane (OOP) direction under static load conditions and evaluated based on the load-bearing and energy dissipation capacities, crack propagations, mortar strengths, and initial stiffnesses. These walls are experimentally investigated to understand the effects of the mortar strength on the infill wall structural behaviors and to assess the effectiveness of the out-of-plane strength formulations. It was found that when the mortar strength is low, the first major crack occurs at the mortar, however, because of the arch mechanism efficiency in this situation the OOP load-carrying and energy dissipation capacities of unreinforced walls can be significantly increased. When the first major crack in the wall occurs in the brick itself, the arc mechanism is provided with delicate sections in the brick, which leads to strength decreasing in the walls. In this case, excessive deviations occur in the out-of-plane strength formulations estimates. This study shows that the arc mechanism, the damage start region and progress can change significantly unreinforced masonry (URM) infill walls behaviors.

In-Plane Vibration Modes of Arbitrarily Thick Disks

1997 ◽  
Author(s):  
Kevin I. Tzou ◽  
Jonathan A. Wickert ◽  
Adnan Akay
Keyword(s):  
Natural Frequencies ◽  
Arbitrary Dimension ◽  
Three Dimensional ◽  
Mode Shapes ◽  
Vibration Modes ◽  
Three Dimensional Model ◽  
Bending Vibration ◽  
Annular Disk ◽  
Out Of Plane ◽  
Plane Bending

Abstract The three-dimensional vibration of an arbitrarily thick annular disk is investigated for two classes of boundary conditions: all surfaces traction-free, and all free except for the clamped inner radius. These two models represent limiting cases of such common engineering components as automotive and aircraft disk brakes, for which existing models focus on out-of-plane bending vibration. For a disk of significant thickness, vibration modes in which motion occurs within the disk’s equilibrium plane can play a substantial role in setting its dynamic response. Laboratory experiments demonstrate that in-plane modes exist at frequencies comparable to those of out-of-plane bending even for thickness-to-diameter ratios as small as 10−1. The equations for three-dimensional motion are discretized through the Ritz technique, yielding natural frequencies and mode shapes for coupled axial, radial, and circumferential deformations. This treatment is applicable to “disks” of arbitrary dimension, and encompasses classical models for plates, bars, cylinders, rings, and shells. The solutions so obtained converge in the limiting cases to the values expected from the classical theories, and to ones that account for shear deformation and rotary inertia. The three-dimensional model demonstrates that for geometries within the technologically-important range, the natural frequencies of certain in- and out-of-plane modes can be close to one another, or even identically repeated.

SEISMIC BEHAVIOR OF UNREINFORCED CONCRETE MASONRY INFILL WALLS

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ziad Azzi ◽  
Caesar Abi Shdid
Keyword(s):  
Reinforced Concrete ◽  
Ground Motion ◽  
Element Model ◽  
Reinforced Concrete Frame ◽  
Infill Wall ◽  
Infill Walls ◽  
Existing Building ◽  
Masonry Infill ◽  
Masonry Infill Walls ◽  
Out Of Plane

The majority of new and existing building inventories in the Middle East consist of reinforced concrete skeletal structures with outer shells composed of unreinforced masonry infill walls. In the absence of any mandatory seismic design requirements, these buildings will sustain catastrophic damage when exposed to high seismic activity. Investigating the behavior of such infill walls when exposed to ground motion is therefore an important topic. Experimental tests using shake table out-of-plane ground motion of the 1940 El Centro earthquake displacement are conducted on 3:10 scaled specimens of a single story reinforced concrete frame with a masonry infill wall in between. The test specimens are constructed with the same materials and construction practices commonly used in the region. Displacements and strains are compared with a finite element model of the frame. Moreover, the observed overall behavior of the infill is compared to that of the computer model. The recorded strains in the mortar joints exceeded cracking limits, whereas the overall stability of the wall in out-of-plane bending was not compromised. Recommendations on the use of these structural elements are formulated.

Cyclic Performance of Two-Story Ductile RC Frames With Infill Walls

2005 ◽  
Author(s):  
Yung-Hsin Yeh ◽  
Wen-I Liao
Keyword(s):  
Model Building ◽  
General Purpose ◽  
Rc Frame ◽  
Building Structures ◽  
Base Shear ◽  
Concrete Frames ◽  
Infill Wall ◽  
Infill Walls ◽  
Rc Frames ◽  
Short Beam

This paper presents the results of the experimental and analytical investigations conducted on four 0.8 scale 2-story one bay ductile reinforced concrete frames with infill nonstructural walls subjected to cyclically increasing loads. The material properties and the member sizes of beams and columns in the four RC frame specimens are identical, but with different types of infill nonstructural wall. These four frames are the pure frame, frame with short column, frame with short beam and frame with wing walls. The four RC frame specimens were designed and constructed according to the general prototype building structures in Taiwan. Test results indicate that the ductility behavior of the frames with infill wall is similar to those of the pure frame. The ultimate base shear strength of the frames with infill walls is higher than those of the pure frame. Analytical results show that the proposed simplified multi-linear beam-column element implemented in a general purpose structural analysis program can accurately simulate the cyclic responses of the RC frame specimen incorporating the elastic flexural stiffness computations suggested by the model building codes.

Surface Micromachined Polysilicon Components Containing Continuous Hinges and Microrivets Used to Realize Three-Dimensional MEMS Structures

2001 ◽  
Vol 687 ◽  
Author(s):  
Edward S. Kolesar ◽  
Matthew D. Ruff ◽  
William E. Odom ◽  
Simon Y. Ko ◽  
Jeffery T. Howard ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Single Layer ◽  
Dimensional Structure ◽  
Plane Rotation ◽  
Arrow Head ◽  
Three Dimensional Structure ◽  
Out Of Plane ◽  
Open Window ◽  
Pass Through ◽  
Glass Reinforcement

AbstractA new polysilicon surface micromachining technique for fabricating and assembling three- dimensional structures has been developed. Single-layer polysilicon elements and laminated polysilicon panels incorporating trapped-glass reinforcement ribs have been successfully fabri- cated on a silicon substrate with robust and continuous hinges that facilitate out-of-plane rotation and assembly. To realize a stable three-dimensional structure, one of the device's elevatable panel components is terminated with an array of open windows, and the mating rotatable element has a matched set of protruding arrowheads/microrivets with flexible barbs that readily flex to facilitate their joining and assembly. Because the arrowhead/microrivet barb tip-to-barb tip sepa- ration is larger than the opening in the mating window, the barbs flex inward as they pass through the open window and then expand to their original shape upon exiting the window, re- sulting in a permanently latched joint and a three-dimensional structure. Three novel arrow- head/microrivet designs have been micromachined to facilitate the latching process, including a simple arrowhead, a high-aspect ratio arrowhead, and a rivet-like structure with a hemispherical shaped cap and a flexible split shank.

Aromatic interactions in proteins, DNA and synthetic receptors

1993 ◽  
Vol 345 (1674) ◽  
pp. 77-85 ◽  
Keyword(s):  
Electrostatic Interactions ◽  
Three Dimensional ◽  
Interaction Model ◽  
Dimensional Structure ◽  
Π Interactions ◽  
Aromatic Stacking ◽  
Dna Base ◽  
Conformational Preferences ◽  
Out Of Plane ◽  
Dna Base Pair

Non-covalent interactions between aromatic molecules (π-π interactions) play a major role in biological molecular recognition. A simple theoretical model which accounts for the geometric properties of π-π interactions is described. The key feature of this model is that it specifically allows for out-of-plane π-electron density in the calculation of electrostatic interactions. Experimental evidence for the validity of the model comes from studies of the geometric distribution of phenylalanine-phenylalanine interactions in protein X-ray crystal structures. The model has also been used to design a synthetic molecular receptor which recognizes p -benzoquinone using H-bonds and edge-to-face π-π interactions. Aromatic stacking interactions provide the crucial link between sequence and three-dimensional structure in double-helical DNA. The π-π interaction model has been used to calculate the conformational preferences of all ten DNA base-pair steps and the results provide new insight into the molecular basis of sequence-dependent DNA structure.

Response of Mid-Rise Reinforced Concrete Frame Buildings to the 2017 Puebla Earthquake

2019 ◽  
Vol 35 (4) ◽  
pp. 1763-1793 ◽  
Author(s):  
Carlos A. Arteta ◽  
Julian Carrillo ◽  
Jorge Archbold ◽  
Daniel Gaspar ◽  
Cesar Pajaro ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
The United States ◽  
Rc Buildings ◽  
Reinforced Concrete Frame ◽  
Infill Walls ◽  
Concrete Frame ◽  
Soft Story ◽  
Masonry Infills ◽  
Rc Frames ◽  
Ductility Capacity

The response of mid-rise reinforced concrete (RC) buildings in Mexico City after the 2017 Puebla Earthquake is assessed through combined field and computational investigation. The Mw 7.1 earthquake damaged more than 500 buildings where most of them are classified as mid-rise RC frames with infill walls. A multinational team from Colombia, Mexico, and the United States was rapidly deployed within a week of the occurrence of the event to investigate the structural and nonstructural damage levels of over 60 RC buildings with 2–12 stories. The results of the study confirmed that older mid-rise structures with limited ductility capacity may have been shaken past their capacity. To elucidate the widespread damage in mid-rise RC framed structures, the post-earthquake reconnaissance effort is complemented with inelastic modeling and simulation of several representative RC framing systems with and without masonry infill walls. It was confirmed that the addition of non-isolated masonry infills significantly impacts the ductility capacity and increases the potential for a soft-story mechanism formation in RC frames originally analyzed and designed to be bare systems.

Seismicity of East Anatolian of Turkey and Failures of Infill Walls Induced by Major Earthquakes

2021 ◽  
pp. 2150017
Author(s):  
Adem Doğangün ◽  
Burak Yön ◽  
Onur Onat ◽  
Mehmet Emin Öncü ◽  
Serkan Sağıroğlu
Keyword(s):  
Structural Damage ◽  
Fault Zones ◽  
Eastern Region ◽  
Damage Evaluation ◽  
Infill Wall ◽  
Infill Walls ◽  
Out Of Plane ◽  
Major Fault ◽  
Van Earthquakes ◽  
In The Beginning

There are three major fault zones in Turkey scattered around the country known as East Anatolian Fault (EAF), North Anatolian Fault (NAF) and Anatolian-Aegean Subduction Zone (AASZ). Last two decades, EAF has been rather quiescent compared with NAF. However, this quiescence was broken in the beginning of the millennium. The strong shaking was started in 2003 with Bingöl earthquake (Mw = 6.3) and the last earthquake on the EAF is the Sivrice-Elazığ (Mw = 6.8) on January 24, 2020. Strong seismicity of these faults damaged the structures severely and caused death of the habitants. This study aims to present, seismotectonic of the region, general characteristics of the earthquakes and more specifically to report structural damage of infill walls of the structure’s damages caused by these earthquakes. Damage evaluation and identification of the observed infill wall damages due to 2003 Bingöl, 2011 Van earthquakes and January 24, 2020 Sivrice-Elazığ earthquake occurred Turkey’s Eastern region, were presented, and possible solutions were suggested. Moreover, the effects of the infill walls on the behavior of structures under static and dynamic load cases are discussed that experienced in these earthquakes. Damages are classified according to formations such as in-plane or out-of-plane, evaluations and the results obtained from the discussions are presented for each category.

Calculating Size Limitations of Non-Load-Bearing Walls under Seismic Loads

2012 ◽  
Vol 204-208 ◽  
pp. 2646-2652
Author(s):  
Chun Xia Yang ◽  
Qing Qing Liu ◽  
Li Juan Sun ◽  
Jian Guo Liang
Keyword(s):  
Mechanical Properties ◽  
Bearing Capacity ◽  
Thickness Ratio ◽  
Seismic Loads ◽  
Infill Walls ◽  
Load Bearing ◽  
Design Specifications ◽  
Out Of Plane

Infill walls,etc. non-load-bearing walls are vulnerable to fracture when these are subjected to out-of-plane seismic loads. Studies suggest that the overall dimensions of non-load-bearing walls are the important parameters to affect its out-of-plane mechanical properties, but most of these researches are qualitative researches, do not give specific size limitations. This paper based on codes has calculated out-of-plane loads of non-load-bearing walls, then bearing capacity check formulas have been deduced when non-load-bearing walls are subjected to out-of-plane seismic loads, finally the size limitations used in the height-thickness ratio check and seismic check are obtained.The conclusions fill up gaps in research of non-load-bearing walls ,and provide reference for the design specifications of non-load-bearing walls.

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