Inversion of shear properties in ocean sediments from numerical Scholte wave

2011 ◽  
Vol 130 (4) ◽  
pp. 2455-2455
Author(s):  
Zhengliang Cao ◽  
Hefeng Dong
Keyword(s):  
Shear Properties ◽  
Scholte Wave

scholarly journals Microstructure and shear properties of ultrasonic-assisted Sn2.5Ag0.7Cu0.1RExNi/Cu solder joints under thermal cycling

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jianguo Cui ◽  
Keke Zhang ◽  
Di Zhao ◽  
Yibo Pan
Keyword(s):  
Shear Strength ◽  
Thermal Cycling ◽  
Solder Joints ◽  
High Reliability ◽  
Sharp Decrease ◽  
Thermal Shock Test ◽  
Shear Properties ◽  
Equivalent Time ◽  
Ultrasonic Assisted ◽  
Reliability Of Solder Joints

AbstractThrough ultrasonic wave assisted Sn2.5Ag0.7Cu0.1RExNi/Cu (x = 0, 0.05, 0.1) soldering test and − 40 to 125 °C thermal shock test, the microstructure and shear properties of Sn2.5Ag0.7Cu0.1RExNi/Cu solder joints under thermal cycling were studied by the SEM, EDS and XRD. The results show that the Sn2.5Ag0.7Cu0.1RExNi/Cu solder joints with high quality and high reliability can be obtained by ultrasonic assistance. When the ultrasonic vibration power is 88 W, the ultrasonic-assisted Sn2.5Ag0.7Cu0.1RE0.05Ni/Cu solder joints exhibits the optimized performance. During the thermal cycling process, the shear strength of ultrasonic-assisted Sn2.5Ag0.7Cu0.1RExNi/Cu solder joints had a linear relationship with the thickness of interfacial intermetallic compound (IMC). Under the thermal cycling, the interfacial IMC layer of ultrasonic-assisted Sn2.5Ag0.7Cu0.1RExNi/Cu solder joints consisted of (Cu,Ni)6Sn5 and Cu3Sn. The thickness of interfacial IMC of ultrasonic-assisted Sn2.5Ag0.7Cu0.1RExNi/Cu solder joints was linearly related to the square root of equivalent time. The growth of interfacial IMC of ultrasonic-assisted Sn2.5Ag0.7Cu0.1RExNi/Cu solder joints had an incubation period, and the growth of IMC was slow within 300 cycles. And after 300 cycles, the IMC grew rapidly, the granular IMC began to merge, and the thickness and roughness of IMC increased obviously, which led to a sharp decrease in the shear strength of the solder joints. The 0.05 wt% Ni could inhibit the excessive growth of IMC, improve the shear strength of solder joints and improve the reliability of solder joints. The fracture mechanism of ultrasonic-assisted Sn2.5Ag0.7Cu0.1RExNi/Cu solder joints changed from the ductile–brittle mixed fracture in the solder/IMC transition zone to the brittle fracture in the interfacial IMC.

scholarly journals An Investigation of Silica Aerogel to Reduce Acoustic Crosstalk in CMUT Arrays

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1459
Author(s):  
Varshitha Yashvanth ◽  
Sazzadur Chowdhury
Keyword(s):  
Silica Aerogel ◽  
Ultrasonic Transducer ◽  
Fluid Interface ◽  
Fractional Bandwidth ◽  
Neighboring Element ◽  
Element Analysis ◽  
Average Improvement ◽  
Capacitive Micromachined Ultrasonic Transducer ◽  
Scholte Wave ◽  
Fea Simulation

This paper presents a novel technique to reduce acoustic crosstalk in capacitive micromachined ultrasonic transducer (CMUT) arrays. The technique involves fabricating a thin layer of diisocyanate enhanced silica aerogel on the top surface of a CMUT array. The silica aerogel layer introduces a highly nanoporous permeable layer to reduce the intensity of the Scholte wave at the CMUT-fluid interface. 3D finite element analysis (FEA) simulation in COMSOL shows that the developed technique can provide a 31.5% improvement in crosstalk reduction for the first neighboring element in a 7.5 MHz CMUT array. The average improvement of crosstalk level over the −6 dB fractional bandwidth was 22.1%, which is approximately 5 dB lower than that without an aerogel layer. The results are in excellent agreement with published experimental results to validate the efficacy of the new technique.

Shear properties of isotropic and homogeneous beam-like solids having arbitrary cross sections

2021 ◽  
Vol 216 ◽  
pp. 231-249
Author(s):  
Massimo Paradiso ◽  
Salvatore Sessa ◽  
Nicolò Vaiana ◽  
Francesco Marmo ◽  
Luciano Rosati
Keyword(s):  
Cross Sections ◽  
Shear Properties ◽  
Homogeneous Beam

Influence of hybridization on in-plane shear properties of 2D & 3D thermoplastic composites reinforced with Kevlar/basalt fabrics

2017 ◽  
Vol 61 ◽  
pp. 396-403 ◽  
Author(s):  
Aswani Kumar Bandaru ◽  
Vijay Kumar Mittal ◽  
Suhail Ahmad ◽  
Naresh Bhatnagar
Keyword(s):  
Thermoplastic Composites ◽  
Plane Shear ◽  
Shear Properties

scholarly journals Lamb-type waves generated by a cylindrical bubble oscillating between two planar elastic walls

2016 ◽  
Vol 472 (2188) ◽  
pp. 20160031 ◽  
Author(s):  
A. A. Doinikov ◽  
F. Mekki-Berrada ◽  
P. Thibault ◽  
P. Marmottant
Keyword(s):  
Resonance Frequency ◽  
Surface Waves ◽  
Wave Speed ◽  
Microfluidic Channel ◽  
Scattered Wave ◽  
Channel Height ◽  
Volume Oscillation ◽  
Scholte Wave ◽  
Rigid Walls ◽  
Elastic Walls

The volume oscillation of a cylindrical bubble in a microfluidic channel with planar elastic walls is studied. Analytical solutions are found for the bulk scattered wave propagating in the fluid gap and the surface waves of Lamb-type propagating at the fluid–solid interfaces. This type of surface wave has not yet been described theoretically. A dispersion equation for the Lamb-type waves is derived, which allows one to evaluate the wave speed for different values of the channel height h . It is shown that for h <λ t , where λ t is the wavelength of the transverse wave in the walls, the speed of the Lamb-type waves decreases with decreasing h , while for h on the order of or greater than λ t , their speed tends to the Scholte wave speed. The solutions for the wave fields in the elastic walls and in the fluid are derived using the Hankel transforms. Numerical simulations are carried out to study the effect of the surface waves on the dynamics of a bubble confined between two elastic walls. It is shown that its resonance frequency can be up to 50% higher than the resonance frequency of a similar bubble confined between two rigid walls.

scholarly journals Shear Properties of Lunar Regolith Simulants

2014 ◽  
Vol 73 ◽  
pp. 178-185 ◽  
Author(s):  
Zhang Lu ◽  
Lv Jianguo
Keyword(s):  
Lunar Regolith ◽  
Shear Properties
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