scholarly journals Failure evaluation of composite concrete using an acoustic emissions technique

2021 ◽  
Vol 1067 (1) ◽  
pp. 012071
Author(s):  
Safaa Kh Al-Jumaili ◽  
Ahmad K Jassim ◽  
Dhia C Ali
1999 ◽  
Vol 24 (4) ◽  
pp. 377-383
Author(s):  
G. A. van zanten ◽  
A. van de sande ◽  
M. P. brocaar

2021 ◽  
Author(s):  
Jian Xiao ◽  
Phillip Liu ◽  
D.C. Pham ◽  
Jim Lua ◽  
Shenal Perera ◽  
...  

2020 ◽  
Vol 12 (05) ◽  
pp. 2050051
Author(s):  
Khawla Essassi ◽  
Jean-Luc Rebiere ◽  
Abderrahim El Mahi ◽  
Mohamed Amine Ben Souf ◽  
Anas Bouguecha ◽  
...  

In this research contribution, the static behavior and failure mechanisms are developed for a three-dimensional (3D) printed dogbone, auxetic structure and sandwich composite using acoustic emissions (AEs). The skins, core and whole sandwich are manufactured using the same bio-based material which is polylactic acid reinforced with micro-flax fibers. Tensile tests are conducted on the skins and the core while bending tests are conducted on the sandwich composite. Those tests are carried out on four different auxetic densities in order to investigate their effect on the mechanical and damage properties of the materials. To monitor the invisible damage and damage propagation, a highly sensitive AE testing method is used. It is found that the sandwich with high core density displays advanced mechanical properties in terms of bending stiffness, shear stiffness, facing bending stress and core shear stress. In addition, the AE data points during testing present an amplitude range of 40–85[Formula: see text]dB that characterizes visible and invisible damage up to failure.


Author(s):  
Álvaro Carrasco ◽  
Franco Méndez ◽  
Félix Leaman ◽  
Cristián Molina Vicuña

2020 ◽  
Vol 6 (3) ◽  
pp. 571-574
Author(s):  
Anna Schaufler ◽  
Alfredo Illanes ◽  
Ivan Maldonado ◽  
Axel Boese ◽  
Roland Croner ◽  
...  

AbstractIn robot-assisted procedures, the surgeon controls the surgical instruments from a remote console, while visually monitoring the procedure through the endoscope. There is no haptic feedback available to the surgeon, which impedes the assessment of diseased tissue and the detection of hidden structures beneath the tissue, such as vessels. Only visual clues are available to the surgeon to control the force applied to the tissue by the instruments, which poses a risk for iatrogenic injuries. Additional information on haptic interactions of the employed instruments and the treated tissue that is provided to the surgeon during robotic surgery could compensate for this deficit. Acoustic emissions (AE) from the instrument/tissue interactions, transmitted by the instrument are a potential source of this information. AE can be recorded by audio sensors that do not have to be integrated into the instruments, but that can be modularly attached to the outside of the instruments shaft or enclosure. The location of the sensor on a robotic system is essential for the applicability of the concept in real situations. While the signal strength of the acoustic emissions decreases with distance from the point of interaction, an installation close to the patient would require sterilization measures. The aim of this work is to investigate whether it is feasible to install the audio sensor in non-sterile areas far away from the patient and still be able to receive useful AE signals. To determine whether signals can be recorded at different potential mounting locations, instrument/tissue interactions with different textures were simulated in an experimental setup. The results showed that meaningful and valuable AE can be recorded in the non-sterile area of a robotic surgical system despite the expected signal losses.


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