Frequency characteristic analysis on acoustic emission of mortar using cement-based piezoelectric sensors

2011 ◽  
Vol 8 (3) ◽  
pp. 321-341 ◽  
Author(s):  
Youyuan Lu ◽  
Zongjin Li
Keyword(s):  
Acoustic Emission ◽  
Frequency Characteristic ◽  
Piezoelectric Sensors ◽  
Characteristic Analysis

scholarly journals Monitoring of Changes Signal Acoustic Emission Signals Using Waveguides

2017 ◽  
Vol 65 (4) ◽  
pp. 1317-1322 ◽  
Author(s):  
Jaroslav Začal ◽  
Petr Dostál ◽  
Michal Šustr ◽  
David Dobrocký
Keyword(s):  
Experimental Study ◽  
Stainless Steel ◽  
Acoustic Emission ◽  
Signal Detection ◽  
Piezoelectric Sensors ◽  
Material Surface ◽  
Medium Density ◽  
Medium Density Fibreboard ◽  
Ae Signal ◽  
Signal Dampening

This paper is focused on possibilities of acoustic emission (AE) signal detection from material surface through waveguide for commonly used piezoelectric sensors. It also considers the experimental study of enhanced detection of occurrence of signal guided through waveguide corpus, its changes and deformities. Aim of this work is verification of several waveguide setup possibilities for maximization of AE signal detection in practice. For this purpose, multiple waveguide setups were manufactured from stainless steel and aluminium alloy. Hsu‑Nielson pen test was utilized for signal actuation. Results demonstrate the differences between measured AE signal with and without employment of waveguide (changes in signal course through different materials and shapes), as well as magnitude of signal dampening and amplification necessary for veritable signal interpretation. Measurements were conducted on agglomerated composite of medium density fibreboard (MDF).

Hardware Trojan Detection Technique Using Frequency Characteristic Analysis of Path Delay in Application Specific Integrated Circuits

2020 ◽  
Vol 10 (2) ◽  
pp. 36-43
Author(s):  
Ha Thai Tran ◽  
Phuc Van Hoang ◽  
Tuan Ngoc Do ◽  
Duong Hai Nguyen
Keyword(s):  
Integrated Circuits ◽  
Frequency Characteristic ◽  
Integrated Circuit ◽  
Hardware Security ◽  
Hardware Trojan ◽  
Path Delay ◽  
Characteristic Analysis ◽  
Hardware Trojan Detection ◽  
Ic Manufacturing ◽  
Application Specific

 Abstract—  Since the last decade, hardware Trojan (HT) have become a serious problem for hardware security because of outsourcing trends in Integrated Circuit (IC) manufacturing. As the fabrication of IC is becoming very complex and costly, more and more chipmakers outsource their designs or parts of the fabrication process. This trend opens a loophole in hardware security, as an untrusted company could perform malicious modifications to the golden circuit at design or fabrication stages. Therefore, assessing risks and proposing solutions to detect HT are very important tasks. This paper presents a technique for detecting HT using frequency characteristic analysis of path delay. The results show that measuring with the frequency step of 0.016 MHz can detect a HT having the size of 0.2% of the original design.Tóm tắt— Từ thập niên 2010, Trojan phần cứng (HT) đã trở thành một vấn đề nghiêm trọng đối với bảo mật phần cứng, do xu hướng thuê sản xuất mạch tích hợp (Integrated Circuit - IC). Khi quá trình chế tạo IC trở nên phức tạp và tốn kém, ngày càng nhiều nhà sản xuất chip lựa chọn phương án thuê lại một phần hoặc toàn bộ thiết kế IC. Xu hướng này tạo ra lỗ hổng trong bảo mật phần cứng, vì một công ty không đáng tin cậy có thể thực hiện các sửa đổi độc hại vào trong mạch nguyên bản ở giai đoạn thiết kế hoặc chế tạo. Do đó, đánh giá rủi ro và đề xuất giải pháp phát hiện HT là một trong những nhiệm vụ hết sức quan trọng. Bài báo này trình bày một giải pháp phát hiện HT sử dụng phân tích đặc tính tần số của độ trễ đường truyền tín hiệu. Kết quả cho thấy, thực hiện khảo sát với bước tần số 0,016 MHz có thể phát hiện được HT có kích thước 0,2% so với thiết kế ban đầu. 

Location of Partial Discharge Source Model Based on Transformer Single-Winding

2014 ◽  
Vol 628 ◽  
pp. 171-176
Author(s):  
Xiao Hui Song ◽  
Xia Feng ◽  
Zhi Zhong Guo ◽  
Jun Feng Di
Keyword(s):  
Frequency Characteristic ◽  
Partial Discharge ◽  
Source Model ◽  
New Method ◽  
Characteristic Analysis ◽  
Software Simulation ◽  
Discharge Source ◽  
Transformer Winding ◽  
Mean And Variance ◽  
Calculation Analysis

This paper presents a new method to locate partial discharge source of transformer single-winding with the transformer single-winding model and Matlab software simulation. This transformer single-winding model is composed of 300m long wire, which is equivalent to the parameter model composed of only capacitors and inductors through the frequency characteristic analysis of transformer winding. In the process of simulation, the bushing and neutral point current of transformer winding are measured when partial discharge occurs in different position. Then we can get position factor related to the current mean and variance measured through calculation, analysis and deduction. Accordingly the position of partial discharge can be found by corresponding relation. This simulation indicates that this method is effective and practical.

scholarly journals Undervoltage Identification in Three Phase Induction Motor Using Low-Cost Piezoelectric Sensors and STFT Technique

Proceedings ◽  
2019 ◽  
Vol 42 (1) ◽  
pp. 72
Author(s):  
Leonardo Carvalho ◽  
Guilherme Lucas ◽  
Marco Rocha ◽  
Claudio Fraga ◽  
Andre Andreoli
Keyword(s):  
Acoustic Emission ◽  
Induction Motor ◽  
Large Scale ◽  
New Technologies ◽  
Low Cost ◽  
Industrial Applications ◽  
Piezoelectric Sensors ◽  
Time Frequency ◽  
Three Phase ◽  
Ae Signals

Three-phase induction motors (IMs) are electrical machines used on a large scale in industrial applications because they are versatile, robust and low maintenance devices. However, IMs are significantly affected when fed by unbalanced voltages. Prolonged operation under voltage unbalance (VU) conditions degrades performance and shortens machine life by producing imbalances in stator currents that abnormally raise winding temperature. With the development of new technologies and research on non-destructive techniques (NDT) for fault diagnoses in IMs, it is relevant to obtain economically accessible, efficient and reliable sensors capable of acquiring signals that allow the identification of this type of failure. The objective of this study is to evaluate the application of low-cost piezoelectric sensors in the acquisition of acoustic emission (AE) signals and the identification of VU through the analysis of short-term Fourier transform (STFT) spectrograms. The piezoelectric sensor makes NDT feasible, as it is an affordable and inexpensive component. In addition, STFT allows time-frequency analyses of acoustic emission signals. In this NDT, two sensors were coupled on both sides of an induction motor frame. The AE signals obtained during the IM operation were processed and the resulting spectrograms were analyzed to identify the different VU levels. After comparing the AE signals for faulty conditions with the signals for the IM operating at balanced voltages, it was possible to obtain a desired identification that confirmed the successful application of low-cost piezoelectric sensors for VU condition detection in three-phase induction machines.

Monitoring of acoustic emission activity using thin wafer piezoelectric sensors

2014 ◽  
Author(s):  
Blaine Trujillo ◽  
Andrei N. Zagrai ◽  
Daniel Meisner ◽  
Sepand Momeni
Keyword(s):  
Acoustic Emission ◽  
Piezoelectric Sensors ◽  
Acoustic Emission Activity ◽  
Emission Activity
Sign in / Sign up

Export Citation Format

Share Document