scholarly journals In-situ seismic verification of non-structural components of unreinforced masonry buildings

2017 ◽  
Vol 19 (1) ◽  
pp. 44-58 ◽  
Author(s):  
Hossein Derakhshan ◽  
Wade D. Lucas ◽  
Michael C. Griffith
Keyword(s):  
Unreinforced Masonry ◽  
Masonry Buildings ◽  
Structural Components

Failure of wall–slab joint in unreinforced masonry building

2016 ◽  
Vol 20 (5) ◽  
pp. 759-771 ◽  
Author(s):  
Feng Lin ◽  
Xiuming Yang ◽  
Keyu Li ◽  
Xianglin Gu ◽  
Xiang Li
Keyword(s):  
Progressive Collapse ◽  
Precast Concrete ◽  
Unreinforced Masonry ◽  
Masonry Building ◽  
Masonry Buildings ◽  
Continuous Cast ◽  
Concrete Floor ◽  
Simply Supported ◽  
Floor Slabs

Investigations on buildings severely damaged due to earthquakes or explosions have indicated that unreinforced masonry buildings with simply supported precast concrete floor slabs exhibit deficiencies in resistance to progressive collapse, compared to unreinforced masonry buildings with continuous cast in situ concrete floor slabs. The collapse mechanisms observed in the two types of unreinforced masonry buildings are closely related to wall–slab joint failure. The purpose of this study is to investigate the failure behavior of wall–slab joints and the effect on the collapse of the two types of unreinforced masonry buildings. Six wall–slab joint specimens and eight grooved wall specimens, induced by partial failure of wall–slab joints, were tested under monotonic vertical and horizontal loading. Numerical models were then developed, verified, and used to perform a parametric study. It was found that the wall–slab joints failed in various modes, that is, slab failure, wall failure, and slab pullout failure. The grooved wall could fail in bending or in compression. Analyses indicated that the collapse of unreinforced masonry buildings with simply supported precast concrete floor slabs develops in both vertical and horizontal directions. However, the collapse of unreinforced masonry buildings with continuous cast in situ concrete floor slabs is prone to develop only in the vertical direction, resulting in improved progressive collapse resistance.

scholarly journals Cyclic Deformation of Microcantilevers Using In-Situ Micromanipulation

2021 ◽  
Author(s):  
A. H. S. Iyer ◽  
M. H. Colliander
Keyword(s):  
Degrees Of Freedom ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Structural Components ◽  
Cyclic Testing ◽  
Phase Boundaries ◽  
Bulk Specimen ◽  
Arbitrary Position ◽  
Three Degrees Of Freedom

Abstract Background The trend in miniaturisation of structural components and continuous development of more advanced crystal plasticity models point towards the need for understanding cyclic properties of engineering materials at the microscale. Though the technology of focused ion beam milling enables the preparation of micron-sized samples for mechanical testing using nanoindenters, much of the focus has been on monotonic testing since the limited 1D motion of nanoindenters imposes restrictions on both sample preparation and cyclic testing. Objective/Methods In this work, we present an approach for cyclic microcantilever bending using a micromanipulator setup having three degrees of freedom, thereby offering more flexibility. Results The method has been demonstrated and validated by cyclic bending of Alloy 718plus microcantilevers prepared on a bulk specimen. The experiments reveal that this method is reliable and produces results that are comparable to a nanoindenter setup. Conclusions Due to the flexibility of the method, it offers straightforward testing of cantilevers manufactured at arbitrary position on bulk samples with fully reversed plastic deformation. Specific microstructural features, e.g., selected orientations, grain boundaries, phase boundaries etc., can therefore be easily targeted.

An experimental and numerical contribution for understanding the in-situ shear behaviour of unreinforced masonry

2021 ◽  
pp. 103389
Author(s):  
Pratik N. Gajjar ◽  
Elena Gabrielli ◽  
Dafne Carolina Martin-Alarcon ◽  
João M. Pereira ◽  
Paulo B. Lourenço ◽  
...  
Keyword(s):  
Unreinforced Masonry ◽  
Shear Behaviour

Claudin-2 is selectively expressed in proximal nephron in mouse kidney

2001 ◽  
Vol 281 (5) ◽  
pp. F966-F974 ◽  
Author(s):  
Alissa H. Enck ◽  
Urs V. Berger ◽  
Alan S. L. Yu
Keyword(s):  
Tight Junction ◽  
Large Family ◽  
Mouse Kidney ◽  
High Rate ◽  
Structural Components ◽  
Water Reabsorption ◽  
Junction Protein ◽  
Confocal Images ◽  
Leaky Epithelium

First published August 15, 2001; 10.1152/ajprenal.00021.2001.—The proximal nephron possesses a leaky epithelium with unique paracellular permeability properties that underlie its high rate of passive NaCl and water reabsorption, but the molecular basis is unknown. The claudins are a large family of transmembrane proteins that are part of the tight junction complex and likely form structural components of a paracellular pore. To localize claudin-2 in the mouse kidney, we performed in situ hybridization using an isoform-specific riboprobe and immunohistochemistry using a polyclonal antibody directed against a COOH-terminal peptide. Claudin-2 mRNA and protein were found throughout the proximal tubule and in the contiguous early segment of the thin descending limb of long-looped nephrons. The level of expression demonstrated an axial increase from proximal to distal segments. In confocal images, the subcellular localization of claudin-2 protein coincided with that of the tight junction protein ZO-1. Our findings suggest that claudin-2 is a component of the paracellular pathway of the most proximal segments of the nephron and that it may be responsible for their uniquely leaky permeability properties.

Distributed Modal Voltages of Nonlinear Paraboloidal Shells With Distributed Neurons

2004 ◽  
Vol 126 (1) ◽  
pp. 47-53 ◽  
Author(s):  
H. S. Tzou ◽  
J. H. Ding
Keyword(s):  
Dynamic Responses ◽  
Dynamic State ◽  
Structural Components ◽  
Shells Of Revolution ◽  
Membrane Component ◽  
Fully Integrated ◽  
In Situ Sensors ◽  
Membrane Components ◽  
Paraboloidal Shell

Effective health monitoring and distributed control of advanced structures depends on accurate measurements of dynamic responses of elastic structures. Conventional sensors used for structural measurement are usually add-on “discrete” devices. Lightweight distributed thin-film piezoelectric neurons fully integrated (laminated or embedded) with structural components can serve as in-situ sensors monitoring structure’s dynamic state and health status. This study is to investigate modal voltages and detailed signal contributions of linear or nonlinear paraboloidal shells of revolution laminated with piezoelectric neurons. Signal generation of distributed neuron sensors laminated on paraboloidal shells is defined first, based on the open-voltage assumption and Maxwell’s principle. The neuron signal of a linear paraboloidal shell is composed of a linear membrane component and a linear bending component; the signal of a nonlinear paraboloidal shell is composed of nonlinear and linear membrane components and a linear bending component due to the von Karman geometric nonlinearity. Signal components and distributed modal voltages of linear and nonlinear paraboloidal shells with various curvatures and thickness are investigated.

Sign in / Sign up

Export Citation Format

Share Document