scholarly journals Measurement of Acceleration Response Functions with Scalable Low-Cost Devices. An Application to the Experimental Modal Analysis

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6637
Author(s):  
Alvaro Magdaleno ◽  
Juan Villacorta ◽  
Lara del-Val ◽  
Alberto Izquierdo ◽  
Antolin Lorenzana
Keyword(s):  
Modal Analysis ◽  
Lower Cost ◽  
Low Cost ◽  
Micro Electro Mechanical System ◽  
Response Functions ◽  
Large Structures ◽  
Frequency Domains ◽  
Recorded Data ◽  
Applied Forces

One of the most popular options in the Structural Health Monitoring field is the tracking of the modal parameters, which are estimated through the frequency response functions of the structure, usually in the form of accelerances, which are computed as the ratio between the measured accelerations and the applied forces. This requires the use of devices capable of synchronously recording accelerations at several points of the structure at high sampling rates and the subsequent computational analysis using the recorded data. To this end, this work presents and validates a new scalable acquisition system based on multiple myRIO devices and digital MEMS (Micro-Electro-Mechanical System) accelerometers, intended for modal analysis of large structures. A simple form of this system was presented by the authors in a previous work, showing that a single board with some accelerometers connected to it got to obtain high quality measurements in both time and frequency domains. Now, a larger system composed by several slave boards connected and synchronized to a master one is presented. Delays lower than 100 ns are found between the synchronised channels of the proposed system. For validation purposes, a case study is presented where the devices are deployed on a timber platform to estimate its modal properties, which are compared with the ones provided by a commercial system, based on analog accelerometers, to show that similar results are obtained at a significantly lower cost.

scholarly journals On the denoising of structural vibration response records from low-cost sensors: a critical comparison and assessment

2021 ◽  
Author(s):  
Gabriele Ravizza ◽  
Rosalba Ferrari ◽  
Egidio Rizzi ◽  
Vasilis Dertimanis
Keyword(s):  
Low Cost ◽  
Vibration Response ◽  
Ambient Vibration ◽  
Structural Vibration ◽  
Discrete Wavelet ◽  
Vibration Signals ◽  
Research Fields ◽  
Frequency Domains ◽  
Value Decomposition

AbstractDue to the increasing quest of adopting low-cost sensors in structural health monitoring (SHM) processes, which may lead to detecting signals contaminated by significant levels of noise, the need to devise appropriate and effective denoising strategies, at the post-processing stage, is becoming more and more essential. Among several approaches proposed in the literature, it has been demonstrated that the employment of discrete wavelet transform (DWT) as a multi-rate filter bank, as well as the use of singular value decomposition (SVD), may result to be quite effective in signal denoising within various research fields, as biological, acoustic and mechanical. Here, DWT- and SVD-based denoising techniques are first independently reconsidered and reimplemented, aiming at exploring their optimal calibration in purifying noise-corrupted vibration response signals encountered in civil engineering applications. Then, a systematic performance evaluation is provided within a comparative framework, developed at an increasing level of noise affecting the measurements, in terms of noise-to-signal (N/S) ratio. In the study, two specific classes of synthetic response signals are first considered, namely earthquake and ambient vibration signals, since they may be assumed as representative of more general non-stationary and stationary signal typologies, respectively. To achieve a complete description of the clarified signal, strengths and weaknesses of the two denoising approaches are explored, in both time and frequency domains. The results prove the effectiveness of the analyzed implementations, especially in purifying seismic response signals, while some limitations may arise concerning the treatment of ambient vibration signals, in particular for the DWT-based denoising technique. Finally, a real case study is analyzed, where both denoising approaches are adapted and employed for clarifying acceleration signals detected on a modern short-span railway bridge, with rather satisfactory results, for both techniques.

scholarly journals Damage Detection and Localization from Dense Network of Strain Sensors

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Simon Laflamme ◽  
Liang Cao ◽  
Eleni Chatzi ◽  
Filippo Ubertini
Keyword(s):  
Damage Detection ◽  
Damage Identification ◽  
Low Cost ◽  
Strain Sensors ◽  
Dense Network ◽  
Virtual Sensors ◽  
Large Structures ◽  
Complex Engineering ◽  
Detection And Localization

Structural health monitoring of large systems is a complex engineering task due to important practical issues. When dealing with large structures, damage diagnosis, localization, and prognosis necessitate a large number of sensors, which is a nontrivial task due to the lack of scalability of traditional sensing technologies. In order to address this challenge, the authors have recently proposed a novel sensing solution consisting of a low-cost soft elastomeric capacitor that transduces surface strains into measurable changes in capacitance. This paper demonstrates the potential of this technology for damage detection, localization, and prognosis when utilized in dense network configurations over large surfaces. A wind turbine blade is adopted as a case study, and numerical simulations demonstrate the effectiveness of a data-driven algorithm relying on distributed strain data in evidencing the presence and location of damage, and sequentially ranking its severity. Numerical results further show that the soft elastomeric capacitor may outperform traditional strain sensors in damage identification as it provides additive strain measurements without any preferential direction. Finally, simulation with reconstruction of measurements from missing or malfunctioning sensors using the concepts of virtual sensors and Kriging demonstrates the robustness of the proposed condition assessment methodology for sparser or malfunctioning grids.

Low Temperature Fault Isolation Using Soft Defect Localization

2012 ◽  
Author(s):  
Kristopher D. Staller
Keyword(s):  
Low Temperatures ◽  
Laser Scanning ◽  
Low Cost ◽  
Fault Isolation ◽  
Laser Scanning Microscopy ◽  
Cold Temperature ◽  
Multiple Point ◽  
Defect Localization ◽  
Low Levels

Abstract Cold temperature failures are often difficult to resolve, especially those at extreme low levels (< -40°C). Momentary application of chill spray can confirm the failure mode, but is impractical during photoemission microscopy (PEM), laser scanning microscopy (LSM), and multiple point microprobing. This paper will examine relatively low-cost cold temperature systems that can hold samples at steady state extreme low temperatures and describe a case study where a cold temperature stage was combined with LSM soft defect localization (SDL) to rapidly identify the cause of a complex cold temperature failure mechanism.

scholarly journals A Regenerative Business Model with Flexible, Modular and Scalable Processes in A Post-Covid Era: The Case of The Spinning Mesh Disc Reactor (SMDR)

2021 ◽  
Vol 13 (12) ◽  
pp. 6944
Author(s):  
Emma Anna Carolina Emanuelsson ◽  
Aurelie Charles ◽  
Parimala Shivaprasad
Keyword(s):  
Business Model ◽  
Low Cost ◽  
Sustainable Manufacturing ◽  
Sustainable Business ◽  
Capital Costs ◽  
Implementing Change ◽  
Chemical Manufacturing ◽  
Manufacturing Techniques ◽  
Flexible Operation

With stringent environmental regulations and a new drive for sustainable manufacturing, there is an unprecedented opportunity to incorporate novel manufacturing techniques. Recent political and pandemic events have shown the vulnerability to supply chains, highlighting the need for localised manufacturing capabilities to better respond flexibly to national demand. In this paper, we have used the spinning mesh disc reactor (SMDR) as a case study to demonstrate the path forward for manufacturing in the post-Covid world. The SMDR uses centrifugal force to allow the spread of thin film across the spinning disc which has a cloth with immobilised catalyst. The modularity of the design combined with the flexibility to perform a range of chemical reactions in a single equipment is an opportunity towards sustainable manufacturing. A global approach to market research allowed us to identify sectors within the chemical industry interested in novel reactor designs. The drivers for implementing change were identified as low capital cost, flexible operation and consistent product quality. Barriers include cost of change (regulatory and capital costs), limited technical awareness, safety concerns and lack of motivation towards change. Finally, applying the key features of a Sustainable Business Model (SBM) to SMDR, we show the strengths and opportunities for SMDR to align with an SBM allowing for a low-cost, sustainable and regenerative system of chemical manufacturing.

Directed earned value management based on ordered fuzzy numbers

2021 ◽  
pp. 1-14
Author(s):  
Seyed Taha Hossein Mortaji ◽  
Siamak Noori ◽  
Morteza Bagherpour
Keyword(s):  
Fuzzy Numbers ◽  
Lower Cost ◽  
Project Managers ◽  
Value Management ◽  
Monitoring And Control ◽  
Earned Value ◽  
Earned Value Management ◽  
Project Monitoring ◽  
And Control

Earned value management is well-known as the most efficient method of project monitoring and control providing relatively reliable information about the project performance. However, this method requires accurate estimates of the progress of project activities, which are always associated with uncertainties that, if ignored or not addressed well, lead to incorrect results. To address this issue, the application of multi-valued logic, in particular fuzzy logic, in earned value management has recently attracted a lot of attention both in practice and research. This paper introduces directed earned value management (DEVM) in which ordered fuzzy numbers are used to express the so-called uncertainties as well as to capture more information about the trend of the project progress. To evaluate the performance of the proposed method, several numerical examples and a case study are presented. The results reveal that compared to the existing methods, DEVM has a lower computational complexity. Also, it doesn’t suffer from the overestimation effect and as a result, it has a higher ability to express project-specific dynamics. In sum, the proposed method allows project managers to make informed decisions that lead to taking preventive and corrective actions promptly and at a lower cost.

A novel adaptable isometric strength analysis and exercise development system design

2021 ◽  
pp. 095441192110155
Author(s):  
Murat Fidan ◽  
Alper Bayrak ◽  
Umid Karli
Keyword(s):  
System Design ◽  
Lower Cost ◽  
Electronic Circuit ◽  
Force Measurement ◽  
Low Cost ◽  
Computer Software ◽  
Isometric Strength ◽  
Strength Analysis ◽  
Strength Measurement ◽  
Development System

In this study, a low-cost and adaptable isometric strength measurement and exercise development system are described. The implemented system consists of mechanical structure, force measurement sensor, electronic circuit, and computer software. Isometric-isotonic (via spring resistance) strength analysis and various exercise programs can be applied with the system. The developed system has a lower cost compared to its counterparts in the literature and has a structure that can be adapted to different machines and measuring methods. The operability and reliability of the isometric strength measurement and exercise development system have been proven by calibration tests.

scholarly journals Comparative Analysis of Low-Cost GNSS OEM Board K706 AND BX316 (Case Study: Bulusidokare Village Sidoarjo Regency)

2021 ◽  
Vol 731 (1) ◽  
pp. 012024
Author(s):  
M N Cahyadi ◽  
E Y Handoko ◽  
R Mardiyanto ◽  
I M Anjasmara ◽  
Khomsin ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Low Cost
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