scholarly journals Elastic Properties Estimation of Masonry Walls through the Propagation of Elastic Waves. An Experimental Investigation

2021 ◽  
Vol 11 (19) ◽  
pp. 9091
Author(s):  
Jacopo Marazzani ◽  
Nicola Cavalagli ◽  
Vittorio Gusella
Keyword(s):  
Elastic Waves ◽  
Structural Parameters ◽  
Masonry Walls ◽  
Artistic Value ◽  
Masonry Material ◽  
Historical Masonry ◽  
The Impact ◽  
Propagation Of Elastic Waves ◽  
Non Destructive

Structural identification is one of the most important steps when dealing with historic buildings. Knowledge of the parameters, which define the mechanical properties of these kinds of structures, is fundamental in preparing interventions aimed at their restoration and strengthening, especially if they have suffered damage due to strong events. In particular, by using non-destructive techniques it is possible to estimate the mechanical characteristics of load-bearing structures without compromising the artistic value of the monumental buildings. In this paper, after recalling the main theoretical aspects, the use of elastic waves propagation through impact tests for the characterization of the masonry walls of a monumental building is described. The impact test allowed us to estimate the elastic characteristics of the homogeneous solid equivalent to masonry material. This confirms the great potential of the non-destructive diagnostics suitable for analyzing important structural parameters without affecting the preservation of historical masonry structures.

scholarly journals Sonic and Impact Test for Structural Assessment of Historical Masonry

2019 ◽  
Vol 9 (23) ◽  
pp. 5148 ◽  
Author(s):  
Alessandro Grazzini
Keyword(s):  
Impact Test ◽  
Structural Parameters ◽  
Historical Masonry ◽  
2016 Amatrice Earthquake ◽  
The Impact ◽  
Santa Maria ◽  
Non Destructive ◽  
Non Destructive Techniques

Diagnostics is a very important tool of knowledge in the field of historical buildings. In particular, non-destructive techniques allow to deepen the study of the mechanical characteristics of the historical walls without compromising the artistic value of the monumental building. A case study of the use of sonic and impact tests was described, performed using the same instrumented hammer, for the characterization of the masonry walls at the Sanctuary of Santa Maria delle Grazie at Varoni, one of the churches damaged in the 2016 Amatrice earthquake. Sonic tests showed the presence of a discontinous masonry texture, as well as confirming the ineffectiveness of the strengthening work made by injections of lime mortar. The impact test allowed us to obtain the elastic modulus of the omogeneous stones of the masonry. The results obtained from the non-destructive techniques were confirmed by the flat jacks test carried out on the building, confirming the great potential of the non-destructive diagnostics suitable for analyzing important structural parameters without affecting the preservation of historical masonry structures.

scholarly journals Tube-Jack Testing for Irregular Masonry Walls: First Studies

2010 ◽  
Vol 133-134 ◽  
pp. 229-234 ◽  
Author(s):  
Luís F. Ramos ◽  
Ziba Sharafi
Keyword(s):  
Stress Level ◽  
Local Stress ◽  
Testing System ◽  
Masonry Walls ◽  
Advantages And Disadvantages ◽  
Masonry Material ◽  
Historical Masonry ◽  
Preliminary Research ◽  
Non Destructive ◽  
Destructive Methods

One of the most well-known non-destructive methods for inspection and diagnosis in historical masonry walls is the flat-jack testing. Although it gives qualitative and valuable results about the local stress level and the deformability of the masonry material, when testing on irregular masonry walls, or walls with larger stone units, experimental and practical problems might occur, leading to inaccurate or useless results. In addition, the testing apparatus is labor, with difficulties in sawing task. Another limitation is the difficulty to test multi-leaves walls. To overturn these problems and to achieve more reliable information, an enhanced type of jacks is proposed in the paper. The new testing system consists of tube-jacks instead of the usual flat-jacks. As part of the preliminary research, analyses with FE models to simulate the differences between the conventional and the enhanced method are presented in the paper. The advantages and disadvantages of both methods are discussed and further research steps are presented.

scholarly journals Impact of Crystalline Orientation on the Switching Field in Barium Titanate Using Piezoresponse Force Spectroscopy

2014 ◽  
Vol 1652 ◽  
Author(s):  
Nikhil K. Ponon ◽  
Daniel J. R. Appleby ◽  
Erhan Arac ◽  
Kelvin S. K. Kwa ◽  
Jonathan P. Goss ◽  
...  
Keyword(s):  
Electric Field ◽  
Phase Change ◽  
Crystal Orientation ◽  
Force Spectroscopy ◽  
Ferroelectric Domain ◽  
Switching Field ◽  
The Impact ◽  
Non Destructive ◽  
Domain Level

ABSTRACTUnderstanding crystal orientation at the ferroelectric domain level, using a non destructive technique, is crucial for the design and characterization of nano-scale devices. In this study, piezoresponse force spectroscopy (PFS) is used to identify ferroelectric domain orientation. The impact of crystal orientation on the switching field of ferroelectric BaTiO3 is also investigated at the domain level. The preferential domain orientations for BaTiO3 thin films prepared by pulsed laser deposition (PLD) in this study are [001], [101] and [111]. They have been mapped onto PFS spectra to show three corresponding switching fields of 460, 330 and 120 kV/cm respectively. In addition, the electric field at which the enhanced piezoresponse occurs was found to vary, due to a phase change. The polarization reversal occurs via a 2-step process (rotation and switching) for [101] and [111] orientations. The piezoresponse enhancement is absent for the [001] (pure switching) domains. The results demonstrate that an electric field induced phase change causes the [101] and [111] domains to reverse polarization at a lower field than the [001] domain.

Durability of a ventilated stone facade: A case study of a limestone facade affected by the corrosion of the anchorage system

2020 ◽  
Author(s):  
Vera Pires de Almeida Ribeiro
Keyword(s):  
Chemical Characterization ◽  
Masonry Walls ◽  
Concrete Walls ◽  
Reinforced Concrete Walls ◽  
Correct Execution ◽  
Anchoring System ◽  
Ventilated Facade ◽  
Non Destructive

<p>The mechanical behavior of a natural stone ventilated facade is inevitably based on the correct execution of both anchoring elements, stone cladding and enclosure support, either with brick masonry walls or reinforced concrete walls. In the case studied in the present work, the origin of the damages on the facade of a building located in Lisbon has been analyzed, where stone detachments were starting to occur. This enclosure is a ventilated facade cladded with Portuguese limestone Lioz slabs. Non-destructive borescope analysis of the metallic anchoring system employed was performed, as well as X-Ray fluorescence laboratory analysis (FRX) for chemical characterization of the anchoring material. Results obtained demonstrated the problem cause on the stone facade due to incorrect metallic anchoring selection and poor execution combined with stress corrosion effect, especially for slabs with larger dimensions.</p>

Influences of an Initial Micro Gap on Wave Transmission

2010 ◽  
Vol 29-32 ◽  
pp. 2662-2667
Author(s):  
Xiao Yun Chen ◽  
Gui Lan Yu
Keyword(s):  
Elastic Waves ◽  
Frictional Contact ◽  
Superposition Method ◽  
Energy Partition ◽  
Non Destructive Evaluation ◽  
Analysis Technique ◽  
Fourier Analysis Technique ◽  
Propagation Of Elastic Waves ◽  
Non Destructive ◽  
Gap Width

The propagation of elastic waves through a micro gap considering frictional contact is investigated in the present paper. Using the Fourier analysis technique and corrective solution superposition method, the problem is solved analytically. Special examples for identical materials are discussed in detail. The results show that the initial gap width has significant influences on the harmonics and energy partition and their relations may be effective on non-destructive evaluation of a pre-existing gap.

scholarly journals Chemistry for Audio Heritage Preservation: A Review of Analytical Techniques for Audio Magnetic Tapes

Heritage ◽  
2019 ◽  
Vol 2 (2) ◽  
pp. 1551-1587
Author(s):  
Federica Bressan ◽  
Richard L. Hess ◽  
Paolo Sgarbossa ◽  
Roberta Bertani
Keyword(s):  
Analytical Techniques ◽  
Video Data ◽  
Cultural Resources ◽  
Chemical Identification ◽  
Heritage Preservation ◽  
The World ◽  
Instrumental Approaches ◽  
The Impact ◽  
Non Destructive

Vast and important cultural resources are entrusted to magnetic tape around the world, but they are susceptible to degradation, which may lead to severe replay problems. Audio magnetic tapes are complex and multicomponent devices containing organic compounds and metal systems, which can be potential catalysts for many degradative reactions in the presence of water, light, or heating. The aim of this review is to collect the literature concerning the analytical determinations and instrumental approaches that can achieve the chemical identification of the components in the tape and the degradation state. Thus, a combination of destructive (such as acetone extraction) and non-destructive techniques (such as ATR FTIR spectroscopy) have been proposed, together with SEM, ESEM, XRD and TGA analyses to assess the chemical and physical characterization of the tape with the purpose to individualize restoration treatments and optimize conditions for preservation. The impact of the studies reviewed in this paper may go beyond audio, being potentially relevant to video, data, instrumentation, and logging tapes.

Characterization of Carbonatation Rate of Alkali-Activated Blast Furnace Slag in Various Environments

2021 ◽  
Vol 325 ◽  
pp. 40-46
Author(s):  
Richard Dvořák ◽  
Petr Hrubý ◽  
Libor Topolář
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Destructive Testing ◽  
Time Intervals ◽  
Impact Echo ◽  
The Impact ◽  
Non Destructive ◽  
Furnace Slag ◽  
Alkali Activated

Carbonatation represents one of the potential degradation processes whose can negatively affect the service life of constructions based on the inorganic binders. The carbonatation depth of the constructions when exposed to various environments is significantly dependent on the existing conditions. The most crucial parameters are the partial pressure of carbon dioxide and humidity. There were selected four environments for the deposition of samples made of the alkali-activated blast furnace slag mortars (exterior, interior, water and CO2 chamber) in this study. These types of environments guarantee the variation of desired parameters influencing the carbonatation rate. The progress of carbonatation was evaluated with a selected technique in time intervals of 28; 56 and 84 days of the sample's exposition to the selected environments. The characterization was done using the destructive techniques (compressive and flexural strength, phenolphthalein method) as well as the non-destructive one like the Impact-Echo or the Ultrasound time passage measurement. The combination of these techniques allows to determine and evaluate the progress of carbonation without the destructive testing of the samples which is necessary for the real applications of these materials.

Characterization of the Pressure Wave Emitted From Implosion of Submerged Cylindrical Shell Structures

2012 ◽  
Author(s):  
Michael D. Shields ◽  
Pawel Woelke ◽  
Najib N. Abboud
Keyword(s):  
Pressure Wave ◽  
Pressure Pulse ◽  
Peak Pressure ◽  
Structural Parameters ◽  
Shell Structures ◽  
High Fidelity ◽  
Pressure Waves ◽  
Structural Configurations ◽  
The Impact

Buckling of submerged cylindrical shells is a sudden and rapid implosion which emits a high pressure pulse that may be damaging to nearby structures. The characteristics of this pressure pulse are dictated by various parameters defining the shell structure such as the length to diameter ratio, shell thickness, material, and the existence and configuration of internal stiffeners. This study examines, through the use of high fidelity coupled fluid-structure finite element computations, the impact of various structural parameters on the resulting pressure wave emanating from the implosion. The results demonstrate that certain structural configurations produce pressure waves with higher peak pressure and impulse thereby enhancing the potential for damage to nearby structures.

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