Characterization of mode selective actuator and sensor systems for Lamb wave excitation

2012 ◽  
Author(s):  
Daniel Schmidt ◽  
Christoph Heinze ◽  
Wolfgang Hillger ◽  
Artur Szewieczek ◽  
Michael Sinapius ◽  
...  
Keyword(s):  
Lamb Wave ◽  
Sensor Systems ◽  
Wave Excitation

Ультразвуковой контроль сварного шва тонкостенной титановой оболочки с индикатором непровара

2021 ◽  
pp. 24-32
Author(s):  
Р.Р. Исхужин ◽  
В.Н. Борисов ◽  
В.Г. Атавин ◽  
А.А. Узких ◽  
К.К. Хафизова
Keyword(s):  
Lamb Wave ◽  
Digital Filters ◽  
Ultrasonic Inspection ◽  
Study Data ◽  
Ultrasonic Waves ◽  
Incomplete Fusion ◽  
Thin Wall ◽  
Wave Excitation ◽  
Great Efficiency ◽  
Metallographic Study

The work considers the methodology of weld ultrasonic inspection of thin-wall (0.6 mm) titanium alloy shells. The paper also presents a review of publications on Lamb wave excitation and propagation, and on applications of ultrasonic inspection of thin-wall weldments. The problem of adhesion detection was successfully solved (weld zones with incomplete fusion conduct ultrasonic waves well, but do not provide mechanical strength). Angular groove is proposed as an indication of incomplete fusion in the weld. We analyzed different propagation modes of Lamb wave in the material and selected optimum inspection parameters. Wavelet analysis and precise digital filters with small increment provided great efficiency. Inspection results of corrupted weld and defect-free regions were analyzed. The results of ultrasonic scanning were compared to metallographic study data.

Influence of a delamination on Lamb wave excitation by a nearby piezoelectric transducer

2020 ◽  
pp. 1045389X2091997 ◽  
Author(s):  
Alisa N Shpak ◽  
Mikhail V Golub ◽  
Inka Mueller ◽  
Artem Eremin ◽  
Jens Kathol ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Piezoelectric Transducer ◽  
Lamb Wave ◽  
Lamb Waves ◽  
Boundary Integral ◽  
Experimental Investigations ◽  
Wave Excitation ◽  
Damage Scenarios ◽  
Active Sensor ◽  
Piezoelectric Wafer

This article presents the results of theoretical and experimental investigations of characteristic changes of Lamb wave excitation and scattering by a strip-like horizontal delamination in a layered elastic waveguide for Lamb waves induced by a piezoelectric wafer active sensor. The boundary integral equation method is used to describe wave propagation in an infinite layered waveguide with a delamination, while the frequency domain spectral element method is employed to model the dynamic behaviour of the piezoelectric wafer active sensor, which allows to simulate debonding between the piezoelectric wafer active sensor and the waveguide. Experimental investigations of the dynamic interaction of the piezoelectric wafer active sensor with a layered plate containing a horizontal delamination is conducted for several damage scenarios, showing a good agreement with the results obtained using the developed mathematical model. The obtained mathematical model is employed to analyse alteration of the piezo-induced Lamb waves including modes’ decomposition due to delamination. The conversion and/or conservation of the Lamb waves on account of a delamination is investigated. The electro-mechanical impedance of the piezoelectric transducer and the stress intensity factors of a delamination are analysed in dependence on the delamination location.

Tolerancing and characterization of curved image sensor systems

2020 ◽  
Vol 59 (28) ◽  
pp. 8814
Author(s):  
F. Zuber ◽  
B. Chambion ◽  
C. Gaschet ◽  
S. Caplet ◽  
S. Nicolas ◽  
...  
Keyword(s):  
Image Sensor ◽  
Sensor Systems

Structure Design, Kinematics and Grasp Constraint of a Metamorphic Robotic Hand for Meat Deboning Operation

2013 ◽  
Author(s):  
Guowu Wei ◽  
Vahid Aminzadeh ◽  
Evangelos Emmanouil ◽  
Jian S. Dai
Keyword(s):  
Closed Form ◽  
Structure Design ◽  
Robotic Hand ◽  
Meat Industry ◽  
Sensor Systems ◽  
Level Control ◽  
Closed Form Solutions ◽  
Low Level ◽  
Structure And Design

A four-fingered metamorphic robotic hand with a reconfigurable palm is presented in this paper with the application in deboning operation of meat industry. This robotic hand has a reconfigurable palm that generates changeable topology and augments dexterity and versatility for the hand. Mechanical structure and design of the robotic hand are presented and based on mechanism decomposition, kinematics of the metamorphic hand is investigated with closed-form solutions leading to the workspace characterization of the robotic hand. Based on the kinematics of the four-fingered metamorphic hand, utilizing product-of-exponentials formula, grasp map and grasp constraint of the hand are then formulated revealing the grasp robustness and manipulability performed by the metamorphic hand. A prototype of the four-fingered metamorphic hand is consequently fabricated and integrated with low level control and sensor systems leading to a scenario of applying the hand in the field of meat industry for deboning operation.

Sign in / Sign up

Export Citation Format

Share Document