Health Monitoring of Medieval Masonry Towers by an Acoustic Emission Approach

2019 ◽  
Vol 817 ◽  
pp. 586-593
Author(s):  
Giuseppe Lacidogna ◽  
Gianni Niccolini ◽  
Alberto Carpinteri
Keyword(s):  
Acoustic Emission ◽  
Health Monitoring ◽  
Masonry Wall ◽  
Masonry Buildings ◽  
Earthquake Occurrence ◽  
Structural Element ◽  
Natural Time ◽  
Non Destructive

Non-destructive tests were performed to assess cracking evolution in two medieval masonry buildings, Sineo and Asinelli towers rising respectively in the Cities of Alba and Bologna, in Italy. As regards the case study of Alba, in situ compressive flat-jack tests on small-sized elements of the tower were conducted in conjunction with acoustic emission (AE) monitoring. At the same time, crack patterns taking place in large volumes of the tower were likewise monitored through the AE technique.As for the case study of Bologna, a masonry wall of the Asinelli tower was monitored during a period of intense seismic activity. The observed correlation between the AE activity in the monitored structural element and local earthquakes points out a significant dependence of deterioration processes in the tower on the action of nearby earthquakes.In both cases, the trends of two evolutionary parameters, the b-value and the natural time (NT) variance κ1, were derived from the AE time series to identify the approach of the monitored structures to a critical state in relation to the earthquake occurrence.

scholarly journals Conservation through knowledge: the case study of Parma Botanic Garden

2021 ◽  
Vol 1203 (2) ◽  
pp. 022047
Author(s):  
Lia Ferrari
Keyword(s):  
18Th Century ◽  
Existing Buildings ◽  
Botanic Garden ◽  
Complex Process ◽  
Critical Interpretation ◽  
Object Material ◽  
The University ◽  
Non Destructive

Abstract In the restoration field it is well known that the preservation of cultural heritage stands on a deep comprehension of the architectural object, material expression of a complex system made of cultural, technological, historical, social and economic issues. The knowledge of such meaningful structures requires the identification of both typological features and peculiar characteristics, within an interactive dialogue between contributions from different disciplines. Thus, the study of existing buildings is a complex process that needs to be planned: that means conceived, organized and realized with a critical method. The paper aims to show an example of this approach by presenting the knowledge path followed for the analysis of the Botanic Garden in Parma, Italy. This green area is located in the south of the city and hosts several buildings including the school of botany and the elegant greenhouse, built at the end of the 18th century. Recently, the restoration of the architectural complex has been proposed, aiming at its valorisation. The design process was supported by the studies and the analysis of the existing buildings carried out by the research group in Restoration of the University of Parma. In the specific, the constructive phases have been investigated through historical archive researches whereas the current structural systems have been studied through the geometric survey. Moreover, in-situ inspections allowed to define materials, deepening the knowledge of structural elements and their state of conservation. Finally, the survey of the crack pattern and decay allows to highlight vulnerabilities and mechanisms of collapse. In this way, it has been possible to understand the architectural structure thanks to the comparison between all data collected. On the other hand, in order to respect the historical construction, these analyses are required to reach a satisfying level of detail with the minimum action on the material construction, preferring non-destructive investigations. This approach entails assumptions and uncertainties that could be managed thanks to a critical interpretation of the results. Thus, the case study of Parma Botanic Garden shows the importance of planning the knowledge path with awareness in order to progressively deepen the comprehension with an interactive dialogue between the architectural object and the restoration issue.

Load-Bearing Capacity Determination of Historic Masonry Structures

2014 ◽  
Vol 923 ◽  
pp. 81-84 ◽  
Author(s):  
Jiří Witzany ◽  
Tomáš Čejka ◽  
Radek Zigler
Keyword(s):  
Mechanical Characteristics ◽  
Masonry Wall ◽  
Probabilistic Methods ◽  
Laboratory Research ◽  
Historic Masonry ◽  
Historical Masonry ◽  
Non Destructive ◽  
Physical And Mechanical Characteristics

The experimental, in-situ and laboratory research has manifested a relatively large variance of the physical and mechanical characteristics of historical masonry found e.g. within a masonry wall, a massive masonry pillar etc. Artical presents the evaluation of the experimentally determined physical and mechanical characteristics of masonry members and the binder obtained by sampling specimens and by non-destructive measurements relies on the application of appropriate probabilistic methods.

scholarly journals Mechanical and Typological Characterization of Traditional Stone Masonry Walls in Old Urban Centres: A Case Study in Viseu, Portugal

Buildings ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 18 ◽  
Author(s):  
José Carlos Domingues ◽  
Tiago Miguel Ferreira ◽  
Romeu Vicente ◽  
João Negrão
Keyword(s):  
Safety Evaluation ◽  
Stone Masonry ◽  
Masonry Walls ◽  
Masonry Buildings ◽  
Existing Buildings ◽  
Urban Center ◽  
In Situ Characterization

Essential for any intervention in existing buildings, a thorough knowledge of both structural and material characteristics is even more important in the case of traditional stone masonry buildings, due both to the variability of this technology’s properties and the degradation buildings might have sustained. In Portugal, a number of in situ and laboratory experimental campaigns has allowed us in recent years to expand the knowledge on the mechanical properties of stone masonry walls. Nevertheless, the existence of different wall typologies built with the same material necessitates that this characterization takes into account the various regional constructive cultures. This paper presents the results obtained through an in-situ characterization campaign carried out in the old urban center of Viseu, for which there is no information available in the literature. Granite stone masonry walls of two different buildings were analyzed and characterized considering their geometrical and material features, contributing to the identification of stone masonry typologies present in the city’s old urban center. Flat-jack testing yielded resistance and deformability parameters to be used both in safety evaluation and intervention design. The properties obtained can be said to be consistent with those deriving from other experimental campaigns, conducted in granite walls of different typologies, throughout the country. Simultaneously, relevant conclusions about the use of flat-jacks to characterize this type of stone masonry were drawn.

scholarly journals Mathematical Modelling Of The Bridges Structural Monitoring I

2015 ◽  
Vol 5 (1) ◽  
pp. 83-90
Author(s):  
G.M.T. Rădulescu ◽  
A.T.G. Rădulescu ◽  
M.V.G. Rădulescu ◽  
Sanda Naş
Keyword(s):  
Mathematical Modelling ◽  
Mathematical Models ◽  
Health Monitoring ◽  
Static Condition ◽  
Structural Monitoring ◽  
Monitoring Systems ◽  
Structural Element ◽  
Steel Temperature ◽  
Or Manager

Abstract Structural Health Monitoring is an extremely complex and relatively expensive activity, and the current offer of tools, methods and technologies is varied, which can lead to a virtually high number of structural monitoring systems that can be customized for each case. In time, the monitoring of bridges became the engine for the development of SHM tools, methods and technologies, or manager monitoring systems. The case study, in continuous quasi-static condition, was performed on Incheon Grand Bridge South Korea. Tracking the behaviour of an objective under the influence of sunshine is performed by VCE Vienna Consulting Engineers ZT GmbH. This paper presents the effect of sunshine on a steel structural element, the first lamella front North line, by comparing data pairs that reflect the cause: steel temperature and the effect: the movement of a sensor mounted on the structural element. The analysis was performed using several software dedicated to mathematical modelling, trying to establish different mathematical models that can be tested and validated.

scholarly journals Challenges and Accomplishments in Mechanical Testing Instrumented by In Situ Techniques: Infrared Thermography, Digital Image Correlation, and Acoustic Emission

2021 ◽  
Vol 11 (15) ◽  
pp. 6718
Author(s):  
Aleksander Sendrowicz ◽  
Aleksander Omholt Myhre ◽  
Seweryn Witold Wierdak ◽  
Alexei Vinogradov
Keyword(s):  
Acoustic Emission ◽  
Digital Image Correlation ◽  
Mechanical Testing ◽  
Digital Image ◽  
Image Correlation ◽  
Deformation And Fracture ◽  
Fracture Of Materials ◽  
Non Destructive ◽  
Fracture Processes

A current trend in mechanical testing technologies is to equip researchers and industrial practitioners with the facilities for non-destructive characterisation of the deformation and fracture processes occurring on different scales. The synergistic effect of such a combination of destructive and non-destructive techniques both widens and deepens existing knowledge in the field of plasticity and fracture of materials and provides the feedback sought to develop new non-destructive testing approaches and in situ monitoring techniques with enhanced reliability, accuracy and a wider scope of applications. The macroscopic standardised mechanical testing is still dominant in the research laboratories and industrial sector worldwide. The present paper reviews multiple challenges commonly faced by experimentalists, aiming at enhancing the capability of conventional mechanical testing by a combination of contemporary infrared thermography (IRT), rapid video imaging (RVI) with non-contact strain mapping possibilities enabled by the digital image correlation (DIC) method, and the acoustic emission (AE) technique providing unbeatable temporal resolution of the stochastic defect dynamics under load. Practical recommendations to address these challenges are outlined. A versatile experimental setup uniting the unique competencies of all named techniques is described alone with the fascinating possibilities it offers for the comprehensive characterisation of damage accumulation during plastic deformation and fracture of materials. The developed toolbox comprising practical hardware and software solutions brings together measuring technologies, data, and processing in a single place. The proposed methodology focuses on the characterisation of the thermodynamics, kinematics and dynamics of the deformation and fracture processes occurring on different spatial and temporal scales. The capacity of the proposed combination is illustrated using preliminary results on the tensile and fatigue behaviour of the fcc Inconel-625 alloy used as a representative example. Dissipative processes occurring in this alloy are assessed through the complex interplay between the released heat, acoustic emission waves, and expended and stored elastic energy.

scholarly journals Acoustic Emission

2021 ◽  
pp. 175-217
Author(s):  
Dimitrios G. Aggelis ◽  
Markus G. R. Sause ◽  
Pawel Packo ◽  
Rhys Pullin ◽  
Steve Grigg ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Health Monitoring ◽  
Crack Nucleation ◽  
Irreversible Processes ◽  
Destructive Testing ◽  
Research And Practice ◽  
Non Invasive ◽  
Recent Trends ◽  
Non Destructive

AbstractAcoustic emission (AE) is one of the most promising methods for structural health monitoring (SHM) of materials and structures. Because of its passive and non-invasive nature, it can be used during the operation of a structure and supply information that cannot be collected in real time through other techniques. It is based on the recording and study of the elastic waves that are excited by irreversible processes, such as crack nucleation and propagation. These signals are sensed by transducers and are transformed into electric waveforms that offer information on the location and the type of the source. This chapter intends to present the basic principles, the equipment, and the recent trends and applications in aeronautics, highlighting the role of AE in modern non-destructive testing and SHM. The literature in the field is vast; therefore, although the included references provide an idea of the basics and the contemporary interest and level of research and practice, they are just a fraction of the total possible list of worthy studies published in the recent years.

Correlation of Acoustic Emission and Corrosion Resistance of Lacquer Coatings on Tin-Free Steel

2015 ◽  
Vol 659 ◽  
pp. 628-632
Author(s):  
Pornsak Srisungsitthisunti ◽  
Siriporn Daopiset ◽  
Noparat Kanjanaprayut
Keyword(s):  
Acoustic Emission ◽  
Corrosion Resistance ◽  
Electrochemical Impedance ◽  
Corrosion Damage ◽  
Corrosion Monitoring ◽  
Metallic Structures ◽  
Crack Monitoring ◽  
Before And After ◽  
Non Destructive

Acoustic emission (AE) is a non-destructive technique which is well known for crack monitoring. Moreover, it has been widely used for corrosion and erosion damage on metallic structures. In this study, AE technique was applied for quick monitoring of corrosion resistance of lacquer coatings on tin free steel and laminated steel for food can-packaging. There were three types of coatings: (A) BPA-NI lacquer, (B) BPA-complied lacquer, and (C) PET lamination. These coatings were investigated in flat-sheet and in deformed sheet. Cathodic disbonding (CD) technique was carried out to cause separation between the coating and the metal substrate and initialize corrosion damage. AE signals was detected immediately with potential excitation, and showed good correlation with coating corrosion resistance during corrosion development. AE count signal matched with resulting current during CD, and proportional to corroded areas. In addition, coatings properties were measured before and after the CD process by electrochemical impedance spectroscopy (EIS). A combination of AE and CD techniques offers an in-situ non-destructive corrosion monitoring of coating quality before and during delamination development, and useful for can-packaging testing.

scholarly journals In Situ Analysis of Plaster Detachment by Impact Tests

2019 ◽  
Vol 9 (2) ◽  
pp. 258 ◽  
Author(s):  
Alessandro Grazzini
Keyword(s):  
In Situ Analysis ◽  
Experimental Methodology ◽  
Historical Buildings ◽  
Architectural Heritage ◽  
Impact Tests ◽  
Innovative Technique ◽  
Non Destructive

The frescoed surfaces of historical buildings may be subject to detachment due to various causes of deterioration. A new non-destructive experimental methodology is described to assess in situ the safety against plaster detachments from historical wall surfaces. Through small and punctual impacts exerted with a specific hammer on the plastered surface it is possible to evaluate the level of the plaster’s detachment. A case study at Palazzo Birago in Turin (Italy) is described to give an example of the application of this innovative technique on frescoed surfaces of historical vaults. The test allows to evaluate the safety of frescoed decorations without affecting the material consistency or creating damage, therefore, making it very suitable in the field of architectural heritage.

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