Research of Ultrasonic Oblique Incidence for Testing Bonding Strength Weakening in SRM

2013 ◽  
Vol 275-277 ◽  
pp. 819-824
Author(s):  
Chun An Ai ◽  
Yu Liu ◽  
Xu Zhi Gao ◽  
Li Jian
Keyword(s):  
Reflection Coefficient ◽  
Bonding Strength ◽  
Oblique Incidence ◽  
Incident Angle ◽  
Average Energy ◽  
Adhesive Layer ◽  
Optimal Test ◽  
Bonding Structure ◽  
Test Strategy ◽  
Reflected Wave

According to bonding strength weakening in SRM bonding structure, the decreases of elastic modulus in adhesive layer have been used to characterise the bonding strength weakening in adhesive layer. Ultrasonic propagation characteristics with bonding strength weakening in adhesive layer has been simulated. Based on analysing the relation between reflection coefficient and incident angle, the optimal test strategy has been put forward. According to test strategy, the experiment of ultrasonic oblique incidence has been done to test bonding strength weakening, the average energy of reflected wave from test points has been taken as signal property to characterise reflection coefficient. The results show that the energy of reflected wave can reflect the extent of bonding strength weakening, can effectively achieve quantitative test of strength weakening.

scholarly journals An Experimental Study on a Composite Bonding Structure for Steel Bridge Deck Pavements

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Xiaoguang Zheng ◽  
Qi Ren ◽  
Huan Xiong ◽  
Xiaoming Song
Keyword(s):  
Tensile Strength ◽  
Shear Strength ◽  
Epoxy Resin ◽  
Bonding Strength ◽  
Bridge Deck ◽  
Steel Bridge ◽  
Shear Tests ◽  
Bonding Structure ◽  
Asphalt Overlay ◽  
Strength Tests

As one of the major contributors to the early failures of steel bridge deck pavements, the bonding between steel and asphalt overlay has long been a troublesome issue. In this paper, a novel composite bonding structure was introduced consisting of epoxy resin micaceous iron oxide (EMIO) primer, solvent-free epoxy resin waterproof layer, and ethylene-vinyl acetate (EVA) hot melt pellets. A series of strength tests were performed to study its mechanical properties, including pull-off strength tests, dumbbell tensile tests, lap shear tests, direct tension tests, and 45°-inclined shear tests. The results suggested that the bonding structure exhibited fair bonding strength, tensile strength, and shear strength. Anisotropic behaviour was also observed at high temperatures. For epoxy resin waterproof layer, the loss of bonding strength, tensile strength, and shear strength at 60°C was 70%, 35%, and 39%, respectively. Subsequent pavement performance-oriented tests included five-point bending tests and accelerated wheel tracking tests. The impacts of bonding on fatigue resistance and rutting propagation were studied. It was found that the proposed bonding structure could provide a durable and well-bonded interface and was thus beneficial to prolong the fatigue lives of asphalt overlay. The choice of bonding materials was found irrelevant to the ultimate rutting depth of pavements. But the bonding combination of epoxy resin waterproof and EVA pellets could delay the early-stage rutting propagation.

scholarly journals A FULL-SCALE STUDY OF THE STRENGTH OF MASSIVE WOOD GLUING WITH MODERN ADHESIVES WHEN OPERATING IN VARIOUS CONDITIONS

2020 ◽  
Vol 10 (1) ◽  
pp. 105-115
Author(s):  
Larisa Ponomarenko ◽  
Ekaterina Kantieva ◽  
Maksim Posluhaev ◽  
Aleksandr Chernyshev
Keyword(s):  
Bonding Strength ◽  
Polyvinyl Acetate ◽  
Adhesive Bonding ◽  
Adhesive Layer ◽  
Correct Choice ◽  
Operating Conditions ◽  
Furniture Manufacturing ◽  
Wooden House ◽  
House Building ◽  
Adhesive Materials

Abstract Glues are widely used to connect various materials, especially since in some cases other options for combining materials are not suitable. The paper deals with the bonding of solid hardwood with modern adhesive materials. Currently, a large group of adhesives of various brands from Russian and foreign manufacturers is presented on the market. In the woodworking industry, adhesives are used in the carpentry and furniture, manufacturing, in wooden house-building, in the production of finishing materials, etc., which are operated outside and inside the premises in constant and variable humidity conditions. Therefore, the correct choice of adhesives plays an important role both for the manufacturer and subsequently for the consumer of the resulting product. In this work, we have studied the dependence of the tensile strength when chipping along the adhesive layer on the type of glue, wood species, and operating conditions. We have selected the following adhesives based on polychloroprene, polyvinyl acetate and rubber. The greatest strength of the adhesive bonding when gluing solid hardwood is given by polyvinyl acetate adhesives. When using the product in conditions of changing temperature and humidity, the bonding strength decreases, in some cases significantly. In fairness, it should be noted that not only the type of glue, but also the type of wood affects the bonding strength

Damascene-Patterned Metal-Adhesive (Cu-BCB) Redistribution Layers

2006 ◽  
Vol 970 ◽  
Author(s):  
Ronald J. Gutmann ◽  
J. Jay McMahon ◽  
Jian-Qiang Lu
Keyword(s):  
Bonding Strength ◽  
Adhesive Bonding ◽  
Process Integration ◽  
Three Dimensional ◽  
Adhesive Layer ◽  
Wafer Level ◽  
Technology Platform ◽  
Metal Bonding ◽  
Wafer Level Packaging ◽  
Metal Metal

ABSTRACTA monolithic, wafer-level three-dimensional (3D) technology platform is described that is compatible with next-generation wafer level packaging (WLP) processes. The platform combines the advantages of both (1) high bonding strength and adaptability to IC wafer topography variations with spin-on dielectric adhesive bonding and (2) process integration and via-area advantages of metal-metal bonding. A copper-benzocyclobutene (Cu-BCB) process is described that incorporates single-level damascene-patterned Cu vias with partially-cured BCB as the bonding adhesive layer. A demonstration vehicle consisting of a two-wafer stack of 2-4 μm diameter vias has shown the bondability of both Cu-to-Cu and BCB-to-BCB. Planarization conditions to achieve BCB-BCB bonding with low-resistance Cu-Cu contacts have been examined, with wafer-scale planarization requirements compared to other 3D platforms. Concerns about stress induced at the tantalum (Ta) liner-to-BCB interface resulting in partial delamination are discussed. While across-wafer uniformity has not been demonstrated, the viability of this WLP-compatible 3D platform has been shown.

scholarly journals Reconfigurable honeycomb metamaterial absorber having incident angular stability

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Javad Shabanpour ◽  
Sina Beyraghi ◽  
Homayoon Oraizi
Keyword(s):  
Electromagnetic Interference ◽  
Oblique Incidence ◽  
Mechanical Performance ◽  
Incident Angle ◽  
Normal Incidence ◽  
Metallic Phase ◽  
Metamaterial Absorber ◽  
Angular Stability ◽  
Ohmic Losses ◽  
Potential Applications

Abstract Ultrawide-angle electromagnetic wave absorbers with excellent mechanical properties are required in many diverse applications such as sensing, and stealth technologies. Here, a novel 3D reconfigurable metamaterial absorber (MMA) consisting of honeycomb and VO2 films is proposed. The proposed MMA exhibits a strong absorptivity above 90% in the widest incident angle up to $$87^\circ $$ 87 ∘ for TM- and TE polarized oblique incidences for THz wave propagating in yoz-plane. Under normal incidence, when VO2 films are in the insulating state, the proposed absorber exhibits high absorptivity in the frequency band of 1–4 THz. By increasing the temperature of the whole structure, the structural transformation of VO2 occurs and turns into the metallic phase. We have shown that under oblique incidence, the ohmic losses of VO2 films especially those parallel to the direction of the incident electric field are the most important absorption principles of the proposed MMA. Due to the ultra wide-angle absorption (angular stability) and mechanical performance, it is expected that the presented MMA may find potential applications, such as camouflage technologies, electromagnetic interference, imaging, and sensing. To the best knowledge of authors, the proposed MMA configuration exhibits the absorptivity in the widest incident angle ever reported.

Sterility screening of platelet concentrates: questioning the optimal test strategy

Vox Sanguinis ◽  
2008 ◽  
Vol 95 (3) ◽  
pp. 181-188 ◽  
Author(s):  
J. Dreier ◽  
M. Störmer ◽  
L. Pichl ◽  
V. Schottstedt ◽  
A. Grolle ◽  
...  
Keyword(s):  
Platelet Concentrates ◽  
Optimal Test ◽  
Test Strategy

Study of Ultrasonic Wave Propagation Characteristics in Multilayer Bonded Structures

2012 ◽  
Vol 204-208 ◽  
pp. 903-907
Author(s):  
Chun An Ai ◽  
Yu Liu ◽  
Zhi Gao Xu ◽  
Jian Li
Keyword(s):  
Wave Propagation ◽  
Reflection Coefficient ◽  
Experimental Research ◽  
Bonding Strength ◽  
Shear Velocity ◽  
Angle Of Incidence ◽  
Propagation Characteristics ◽  
Reflection And Transmission ◽  
Ultrasonic Wave Propagation ◽  
Reflection And Transmission Coefficient

The reflection and transmission coefficient equations in multilayer bonded structures have been achieved by improved global matrix algorithm. The change of bonded strength have been simulated by the change of shear velocity in bonded layer.The curve between reflection coefficient and angle of incidence in immersion and plane ultrasonic longitudinal wave have been calculated in different bonding strength and the same frequency. The emulational graph had been compared and analyzed. The quantitative test of bonding strength and orientation of poor bonded district have been implemented. The conclusion can provide theoretic guidance for experimental research of bonded strength.

Frequency-dependent spherical-wave reflection coefficient inversion in acoustic media: Theory to practice

Geophysics ◽  
2020 ◽  
Vol 85 (4) ◽  
pp. R425-R435
Author(s):  
Binpeng Yan ◽  
Shangxu Wang ◽  
Yongzhen Ji ◽  
Xingguo Huang ◽  
Nuno V. da Silva
Keyword(s):  
Reflection Coefficient ◽  
Wave Reflection ◽  
Incident Angle ◽  
Spherical Wave ◽  
Frequency Dependent ◽  
Amplitude Variation With Offset ◽  
Reflection Data ◽  
Alternative Approach ◽  
Acoustic Media ◽  
The Time Domain

As an approximation of the spherical-wave reflection coefficient (SRC), the plane-wave reflection coefficient does not fully describe the reflection phenomenon of a seismic wave generated by a point source. The applications of SRC to improve analyses of seismic data have also been studied. However, most of the studies focus on the time-domain SRC and its benefit to using the long-offset information instead of the dependency of SRC on frequency. Consequently, we have investigated and accounted for the frequency-dependent spherical-wave reflection coefficient (FSRC) and analyzed the feasibility of this type of inversion. Our inversion strategy requires a single incident angle using reflection data for inverting the density and velocity ratios, which is distinctly different from conventional inversion methods using amplitude variation with offset. Hence, this investigation provides an alternative approach for estimating media properties in some contexts, especially when the range of aperture of the reflection angles is limited. We apply the FSRC theory to the inversion of noisy synthetic and field data using a heuristic algorithm. The multirealization results of the inversion strategy are consistent with the feasibility analysis and demonstrate the potential of the outlined method for practical application.

Angle‐dependent reflectivity by means of prestack migration

Geophysics ◽  
1990 ◽  
Vol 55 (9) ◽  
pp. 1223-1234 ◽  
Author(s):  
C. G. M. de Bruin ◽  
C. P. A. Wapenaar ◽  
A. J. Berkhout
Keyword(s):  
Reflection Coefficient ◽  
Wave Field ◽  
Grid Point ◽  
Depth Level ◽  
Wave Fields ◽  
Prestack Migration ◽  
Reflected Wave ◽  
Zero Offset ◽  
Source Wave ◽  
Angle Dependent Reflectivity

Most present day seismic migration schemes determine only the zero‐offset reflection coefficient for each grid point (depth point) in the subsurface. In matrix notation, the zero‐offset reflection coefficient is found on the diagonal of a reflectivity matrix operator that transforms the illuminating source‐wave field into a reflected‐wave field. However, angle dependent reflectivity information is contained in the full reflectivity matrix. Our objective is to obtain angle‐dependent reflection coefficients from seismic data by means of prestack migration (multisource, multioffset). After downward extrapolation of source and reflected wave fields to one depth level, the rows of the reflectivity matrix (representing angle‐dependent reflectivity information for each grid point at that depth level) are recovered by deconvolving the reflected wave fields with the related source wave fields. This process is carried out in the space‐frequency domain. In order to preserve the angle‐dependent reflectivity in the imaging we must not only add all frequency contributions but we should extend the imaging principle by adding along lines of constant angle in the wavenumber‐frequency domain. This procedure is carried out for each grid point. The resulting amplitude information provides a rigorous approach to amplitude‐versus‐offset related methods. The new imaging technique has been tested on media with horizontal layers. However, with our shot‐record oriented algorithm it is possible to handle any subsurface geometry. The first tests show excellent results up to high angles, both in the acoustic and in the elastic case. With angle‐dependent reflectivity information it becomes feasible to derive detailed velocity and density information in a subsequent stratigraphic inversion step.

scholarly journals The speed, reflection and intensity of waves propagating in flexible tubes with aneurysm and stenosis: Experimental investigation

2019 ◽  
Vol 233 (10) ◽  
pp. 979-988 ◽  
Author(s):  
Wisam S Hacham ◽  
Ashraf W Khir
Keyword(s):  
Reflection Coefficient ◽  
Wave Speed ◽  
Expansion Waves ◽  
Reflected Wave ◽  
Compression And Expansion ◽  
Contracting Heart ◽  
Propagation Of Waves ◽  
Flexible Tubes ◽  
Mother Tube

A localized stenosis or aneurysm is a discontinuity that presents the pulse wave produced by the contracting heart with a reflection site. However, neither wave speed ( c) in these discontinuities nor the size of reflection in relation to the size of the discontinuity has been adequately studied before. Therefore, the aim of this work is to study the propagation of waves traversing flexible tubes in the presence of aneurysm and stenosis in vitro. We manufactured different sized four stenosis and four aneurysm silicone sections, connected one at a time to a flexible ‘mother’ tube, at the inlet of which a single semi-sinusoidal wave was generated. Pressure and velocity were measured simultaneously 25 cm downstream the inlet of the respective mother tube. The wave speed was measured using the PU-loop method in the mother tube and within each discontinuity using the foot-to-foot technique. The stenosis and aneurysm dimensions and c were used to determine the reflection coefficient ( R) at each discontinuity. Wave intensity analysis was used to determine the size of the reflected wave. The reflection coefficient increased with the increase and decrease in the size of the aneurysm and stenosis, respectively. c increased and decreased within stenosis and aneurysms, respectively, compared to that of the mother tube. Stenosis and aneurysm induced backward compression and expansion waves, respectively; the size of which was related to the size of the reflection coefficient at each discontinuity, increases with smaller stenosis and larger aneurysms. Wave speed is inversely proportional to the size of the discontinuity, exponentially increases with smaller stenosis and aneurysms and always higher in the stenosis. The size of the compression and expansion reflected wave depends on the size of R, increases with larger aneurysms and smaller stenosis.

Sign in / Sign up

Export Citation Format

Share Document