The Burdened Area as a Structural Indicator of Interface Bonding Strength

1998 ◽  
Vol 120 (2) ◽  
pp. 137-142
Author(s):  
Y. F. Luo
Keyword(s):  
Bonding Strength ◽  
Mechanical Design ◽  
Structural Parameters ◽  
Classical Equation ◽  
Structural Effect ◽  
Fracture Mechanisms ◽  
Interface Debonding ◽  
Interface Adhesion ◽  
Interface Bonding Strength ◽  
Structural Indicator

In laminate structures, the interface debonding failures usually result from very complex fracture mechanisms which lead to different strengthening approaches. The bonding strength of two dissimilar bodies depends, to a great extent, on the bulk materials and the bonding structure in addition to the intrinsic interface adhesion. The structural effect on bonding strength will be emphasized in this investigation. The analysis will exhibit the relationship of materials, structures, and interface adhesion which is essential in understanding the failure mechanisms. This paper proposes that the burdened area on an interface is, according to experimental and analytical results, a structural indicator for bonding strength. Such a comprehensive parameter makes it easy to determine the complex contributions of so many structural parameters to the bonding strength. Although there are many microscopic observations of separated surfaces which support the concept of burdened area, a direct measurement of the burdened area is difficult in practice. Therefore an analytical or numerical evaluation is necessary. The solutions from the classical equation of elastic plate will be used to determine the distribution of interface stress as well as the size of burdened area. The bonding strength is considered as fracture toughness which is directly related with the burdened area. As a useful indicator for evaluating the bonding strength, the burdened area includes the effects of many structural parameters and mechanical properties, such as: elastic modulus, Poisson’s ratio, layer thickness, slanting angel, and corner radius. Burdened area is a property of structure because it is independent of the peeling loads, the material’s yielding strength and interface adhesion. As far as energy release rate is concerned, the boundary load is virtually distributed on the whole burdened area. The concept of burdened area will facilitate mechanical design of bonding strength and leads to a better understanding of various debonding failures.

scholarly journals Effect of Pulse Current-Assisted Rolling on the Interface Bonding Strength and Microstructure of Cu/Al Laminated Composite

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1555
Author(s):  
Hao Song ◽  
Weixin Hao ◽  
Xiaowei Mu ◽  
Tingzhuang Han ◽  
Chaojie Che ◽  
...  
Keyword(s):  
Bonding Strength ◽  
Pulse Current ◽  
Intermetallic Phase ◽  
Laminated Composite ◽  
Copper Surface ◽  
Copper Sheet ◽  
Rolling Method ◽  
Small Cracks ◽  
Interface Bonding Strength ◽  
Shear Interface

In this paper, Cu/Al laminated composite was prepared by adopting the pulse current-assisted rolling method, and the microstructure and mechanical properties of the material were investigated. The results showed that the Cu/Al laminated composite with pulsed current was significantly strengthened. The composite interface of Cu/Al laminated composite with pulse current-assisted rolling was found without intermetallic phase, and its bonding mode was mainly mechanical combined. The number of reticulated ridges increased at the shear interface. The small cracks on the copper surface were firmly embedded in the aluminum metal. There were obvious folds on the copper surface without aluminum embedding. The structural change of the bonding interface increases the contact area between copper sheet and aluminum sheet, thereby enhancing the bonding strength of the Cu/Al laminated composite.

Thermal Shock Behavior and Bonding Strength of MoSi2-BaO-Al2O3-SiO2 Gradient Porous Coating with Polymethyl Methacrylate Addition for Porous Fibrous Insulations

2018 ◽  
Vol 281 ◽  
pp. 493-498
Author(s):  
Ya Yu Su ◽  
Xiao Lei Li ◽  
Hui Jie Tang ◽  
Zhi Hao Zhao ◽  
Jian He
Keyword(s):  
Porous Structure ◽  
Thermal Shock ◽  
Bonding Strength ◽  
Thermal Shock Resistance ◽  
Porous Coating ◽  
Bonding Layer ◽  
Interface Bonding ◽  
Shock Resistance ◽  
Thermal Shock Behavior ◽  
Interface Bonding Strength

In order to improve the thermal shock behavior of high temperature resistant coating on porous fibrous referactory insulations, the MoSi2-BaO-Al2O3-SiO2(MoSi2-BAS) gradient porous coatings were designed by preparing a dense surface layer and a porous bonding layer with the method of brushing and subsequent sintering at 1773 K. The porous bonding layer was obtained by adding polymethyl methacrylate (PMMA) as pore former. As the content of PMMA increases, the MoSi2-BAS coatings changed from a dense structure into a gradient porous structure. The interface bonding strength and thermal shock resistance of the MoSi2-BAS coatings were investigated. The result shows that the as-prepared coating with gradient porous structure exhibited excellent thermal shock resistance, which remained gradient structure without cracking after thermal cycling 100 times between 1773 K and room temperature. And the interface bonding strength of the gradient porous coating reached 1.5±0.08 Mpa, which was much better than that of the dense coating.

On the Interface between Porcelain and Titanium

2008 ◽  
Vol 368-372 ◽  
pp. 1618-1620 ◽  
Author(s):  
Li Tong Guo ◽  
Ji Qiang Gao ◽  
Xiao Chen Liu ◽  
Tian Wen Guo ◽  
Zeng Ying He
Keyword(s):  
Bonding Strength ◽  
Titanium Surface ◽  
Artificial Saliva ◽  
Rutile Phase ◽  
Interface Debonding ◽  
Oxide Interface ◽  
Dental Porcelain ◽  
Flexure Test

Low-fusing dental porcelain was fused on titanium surface. The adhesion between the titanium and porcelain was evaluated by three-point flexure test. It was shown that the failure of the titaniumporcelain predominantly occurred at the alloy-oxide interface. Rutile phase was present on the interface debonding from porcelain. The influence of corrosion on bonding strength was also investigated. The results suggested that, after being immersed in artificial saliva with pH of 2.7, 5.4 and 7.0, no decreasing of the bonding strength of Ti-porcelain occurred.

Optimization of a Bioinspired Piezocomposite Pump Based on an Electromechanical Model

2020 ◽  
Author(s):  
Xin Shan ◽  
Onur Bilgen
Keyword(s):  
Performance Metrics ◽  
Mechanical Design ◽  
Structural Parameters ◽  
Beam Model ◽  
Electromechanical Model ◽  
Pumping System ◽  
Active Segment ◽  
Work Done ◽  
Euler Bernoulli Beam ◽  
Bernoulli Beam Model

Abstract This paper presents the mechanical design and modeling of an active segment of a bioinspired piezocomposite aquatic pump. The design and analysis is based on an electromechanical Euler-Bernoulli beam model. The self-contained propulsion/pumping system is composed of a series of piezo-active soft cymbal-like segments that are connected by passive soft films. By applying coordinated excitations for expansion and contraction to different active segments, the design creates a traveling wave along the pump axis, which in return propels the fluid to generate a unidirectional thrust force. In the model, the insulation and mechanical properties of the waterproofing sealant layer are considered. Using the proposed electromechanical model, a parametric analysis is conducted to understand the effectiveness of the cymbal-like piezocomposite active segment. Two performance metrics are considered, including the area change of the enclosed by the cymbal-like segment, and the work done by the actuators. The optimal structural parameters of the piezocomposite pump are decided by these performance metrics.

Experimental evaluation of the tensile bonding strength of the basalt fiber-reinforced polymer–concrete interface

2020 ◽  
Vol 23 (15) ◽  
pp. 3323-3334
Author(s):  
Buntheng Chhorn ◽  
WooYoung Jung
Keyword(s):  
High Temperature ◽  
Bonding Strength ◽  
Basalt Fiber ◽  
Fiber Reinforced Polymer ◽  
Polymer Concrete ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Interface Bonding Strength ◽  
Concrete Interface ◽  
Basalt Fiber Reinforced Polymer

The bonding performance of basalt fiber-reinforced polymer and concrete substrate has a significant effect on the reliability of externally strengthened existing concrete structure, due to being the most vulnerable element to failure in this fiber-reinforced polymer–concrete strengthening system. Its failure can result in the failure of the whole structure. Although many previous researchers have been interested in the tensile bonding strength of carbon fiber-reinforced polymer and glass fiber-reinforced polymer–concrete interface, that of basalt fiber-reinforced polymer–concrete interface has been very limited. Thus, the objective of this study is to experimentally assess the tensile bonding strength of the basalt fiber-reinforced polymer–concrete interface. The effects of high temperature, freezing–thawing cycles, type of resin, and concrete crack widths on the tensile bonding strength are also investigated. The pull-off experiment is conducted according to ASTM D7522/D7522M-15. A total of 205 core specimens of 50 mm diameter and 10 mm depth were taken from 41 concrete beams. The experimental results illustrate that both freezing–thawing and high-temperature condition have a substantial effect on the bonding strength of the basalt fiber-reinforced polymer–concrete interface. Bonding strength was decreased within the range of about 9%–30% when the number of freezing–thawing cycles increases from 100 to 300; likewise, it was decreased up to 30% when the exposure temperature rises to 200°C. Also, the specimens which were repaired to close their cracks by epoxy resin had no significant effect on the bonding strength of basalt fiber-reinforced polymer–concrete interface, when the specimens had crack width of less than 1.5 mm.

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