Improvement of interface anchoring by ultrasonic vibration for adhesively bonded CFRP/Al joints

2021 ◽  
pp. 073168442110216
Author(s):  
Hui Wang ◽  
Xuetong Tong ◽  
Wei Ji ◽  
Yizhe Chen ◽  
Lin Hua ◽  
...  
Keyword(s):  
Ultrasonic Vibration ◽  
Bonding Strength ◽  
Adhesive Bonding ◽  
Capillary Tube ◽  
Physical Adsorption ◽  
Energy Dispersive Spectrometer ◽  
Fiber Reinforced Polymer ◽  
Adhesively Bonded ◽  
Reinforced Polymer ◽  
Bonding Area

Adhesively bonded carbon fiber reinforced polymer (CFRP)/Al joints have been widely used in engineering field. However, the bonding strength still needs to be improved. In this study, ultrasonic vibration was applied during the adhesive bonding to promote the micromechanical anchoring at the interface of CFRP/Al joints. Ultrasonic vibration was exerted on the CFRP laminate to transmit the vibration to the adhesive bonding area once the joint was assembled. The strength and the strength consistency of the joints were increased by 45% and 50%, respectively. Scanning electron microscope (SEM) and energy dispersive spectrometer (EDS) results showed that the ultrasonic vibration promoted the filling of the adhesive into the microstructures of the adherends and achieved a more compact bonding. Viscosity and contact angle of the adhesive were measured, and both of them were decreased greatly under the ultrasonic vibration, indicating that the ultrasonic vibration can increase the fluidity of the adhesive and force the wetting between the materials. Ultrasonic capillary experiment was then conducted. The adhesive in the capillary tube was prompted to rise obviously, and the meniscus was inverted with ultrasonic vibration, showing that the ultrasonic vibration produced a driving effect on filling of the adhesive in the microstructures. Therefore, the joints exhibited improved bonding strength owing to the enhanced micromechanical anchoring and physical adsorption at the bonding interface. This study is of great significance for understanding and optimization of the ultrasonic vibration strengthened adhesive bonding.

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.

scholarly journals An Anchoring Groove Technique to Enhance the Bond Behavior between Heat-Damaged Concrete and CFRP Composites

Buildings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 232
Author(s):  
Rajai Al-Rousan ◽  
Mohammad AL-Tahat
Keyword(s):  
Elevated Temperatures ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Bond Behavior ◽  
Reinforced Polymer ◽  
Cfrp Composites ◽  
Bonding Area ◽  
Cfrp Sheet ◽  
Cfrp Composite ◽  
Type Of Failure

This experimental study was conducted to evaluate the effectiveness of using carbon fiber-reinforced polymer (CFRP) composites with special anchoring grooves, specifically in terms of the ability of the concrete–CFRP bond to withstand elevated temperatures. The obtained findings of this experiment clearly highlighted the effectiveness of the direction of the anchoring grooves on the behavior of the concrete–CFRP bonding area. The results also showed that high temperatures lessen the bond’s strength and the ultimate slippage. On the other hand, this study showed that increasing the length of the CFRP sheet resulted in enhancement of the bond’s strength and slippage. When exposed to temperatures above 500 °C, the structures’ residual splitting and compression strength decreased significantly, resulting in the bond’s strength reducing to 67% and the slippage to 19%, with respect to the control samples. In the non-grooved and vertically grooved beams, the CFRP–concrete bond showed a skin-peeling type of failure. It appeared, also, that the temperature and the number of anchored grooves significantly affected the bonding area of the surface; as the surface was exposed to failure in adhesion, more concrete remained attached to the CFRP composite, signifying a stronger attachment.

Failure Modes in Hybrid Titanium Composite Laminates

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Johannes Reiner ◽  
Martin Veidt ◽  
Matthew Dargusch
Keyword(s):  
Composite Laminates ◽  
High Performance ◽  
Adhesive Bonding ◽  
Failure Modes ◽  
Impact Resistance ◽  
Surface Preparation ◽  
Matrix Cracking ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Reinforced Polymer

Hybrid titanium composite laminates (HTCLs) combine the benefits of thin titanium sheets and fiber-reinforced polymer (FRP) composite laminates to design high performance light-weight materials with optimized impact resistance, fracture toughness, durability, and/or thermal performance. This paper starts with a detailed review of typical failure modes observed in HTCLs. The critical manufacturing process of thin grade II titanium sheets combined with HexPly G947/M18 carbon fiber-reinforced polymer laminates is described in detail. This includes the evaluation of titanium surface preparation techniques, which guarantee good adhesive bonding. A systematic experimental study of different HTCL configurations under tensile loading confirms that the major failure modes are debonding between the titanium sheet and the FRP laminate, matrix cracking in the 90 deg plies of the FRP laminate and interlaminar delamination. The results show that HTCLs made from woven carbon FRP plies show higher ultimate strengths and strain at breaks than HTCLs containing a cross-ply composite core made from unidirectional (UD) prepreg.

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