scholarly journals Mechanical Properties of Transparent Epoxy Adhesives for Glass Structures

2021 ◽  
Vol 1203 (3) ◽  
pp. 032138
Author(s):  
Markéta Zikmundová ◽  
Martina Eliášová
Keyword(s):  
Shear Strength ◽  
Failure Mode ◽  
Civil Engineering ◽  
Experimental Testing ◽  
Epoxy Adhesive ◽  
Load Bearing ◽  
Lap Shear ◽  
Epoxy Adhesives ◽  
Lack Of Information ◽  
Adhesive Connections

Abstract Adhesive connections are commonly used in many industries as automotive, aerospace, electronics and also in civil engineering. Adhesives in civil engineering are used for non-load bearing structures but nowadays are requirements for using adhesive also for load- bearing structures especially for glass structures. Silicones are mostly used adhesives in civil engineering, they have good resistance to external environment but their lower strength and lower stiffness does not meet requirements for many applications. For this reason, are better semi-rigid or rigid adhesives but there is a lack of information about them. The paper is focused on experimental testing of transparent adhesive connection glass to glass. Four epoxy adhesives were chosen for double lap shear joint. Specimen were exposed to shear test until failure. Shear force and displacement were measured during test. Shear stress, elongation at break, shear modulus and failure mode were obtained from the tests. Only one epoxy adhesive had low adhesion to glass. Specimen with this adhesive had the lowest shear strength. Other three adhesives showed good adhesion to glass and had shear strength 6.5 times higher. Failure mode of specimen with these adhesives was always breaking of the glass.

scholarly journals Microstructure and mechanical properties of an ultrasonic spot welded aluminum alloy: the effect of welding energy

2021 ◽  
Author(s):  
He Peng ◽  
Daolun Chen ◽  
Xianquan Jiang
Keyword(s):  
Shear Strength ◽  
Aluminum Alloy ◽  
Cyclic Loading ◽  
Crack Growth ◽  
Failure Mode ◽  
Spot Welding ◽  
Energy Levels ◽  
Lap Shear Strength ◽  
Pull Out ◽  
Lap Shear

The aim of this study is to evaluate the microstructures, tensile lap shear strength, and fatigue resistance of 6022-T43 aluminum alloy joints welded via a solid-state welding technique–ultrasonic spot welding (USW)–at different energy levels. An ultra-fine necklace-like equiaxed grain structure is observed along the weld line due to the occurrence of dynamic crystallization, with smaller grain sizes at lower levels of welding energy. The tensile lap shear strength, failure energy, and critical stress intensity of the welded joints first increase, reach their maximum values, and then decrease with increasing welding energy. The tensile lap shear failure mode changes from interfacial fracture at lower energy levels, to nugget pull-out at intermediate optimal energy levels, and to transverse through-thickness (TTT) crack growth at higher energy levels. The fatigue life is longer for the joints welded at an energy of 1400 J than 2000 J at higher cyclic loading levels. The fatigue failure mode changes from nugget pull-out to TTT crack growth with decreasing cyclic loading for the joints welded at 1400 J, while TTT crack growth mode remains at all cyclic loading levels for the joints welded at 2000 J. Fatigue crack basically initiates from the nugget edge, and propagates with “river-flow” patterns and characteristic fatigue striations. Keywords: aluminum alloy; ultrasonic spot welding; EBSD; microstructure; tensile strength; fatigue

Synergistic effect of graphene and carbon nanotube on lap shear strength and electrical conductivity of epoxy adhesives

2019 ◽  
Vol 136 (42) ◽  
pp. 48056 ◽  
Author(s):  
Sensen Han ◽  
Qingshi Meng ◽  
Xiao Pan ◽  
Tianqing Liu ◽  
Shuocheng Zhang ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Shear Strength ◽  
Carbon Nanotube ◽  
Synergistic Effect ◽  
Lap Shear Strength ◽  
Lap Shear ◽  
Epoxy Adhesives

Effect of different carbon nano-fillers on rheological properties and lap shear strength of epoxy adhesive joints

2016 ◽  
Vol 82 ◽  
pp. 53-64 ◽  
Author(s):  
Panta Jojibabu ◽  
M. Jagannatham ◽  
Prathap Haridoss ◽  
G.D. Janaki Ram ◽  
Abhijit P. Deshpande ◽  
...  
Keyword(s):  
Shear Strength ◽  
Rheological Properties ◽  
Epoxy Adhesive ◽  
Adhesive Joints ◽  
Lap Shear Strength ◽  
Lap Shear

scholarly journals Comparative Study on the Impact Wedge-Peel Performance of Epoxy-Based Structural Adhesives Modified with Different Toughening Agents

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1549
Author(s):  
Gyeong-Seok Chae ◽  
Hee-Woong Park ◽  
Jung-Hyun Lee ◽  
Seunghan Shin
Keyword(s):  
Shear Strength ◽  
Automotive Industry ◽  
Impact Resistance ◽  
High Energy ◽  
Epoxy Adhesive ◽  
Absorbed Energy ◽  
Structural Adhesives ◽  
Epoxy Adhesives ◽  
The Impact ◽  
Modified Epoxy

Epoxy adhesives are widely used in various industries because of their high heat and chemical resistance, high cohesion, and minimal shrinkage. Recently, epoxy adhesives have been applied in the automotive industry as structural adhesives for lightweight vehicles. However, the brittleness of the epoxy is an obstacle for this application, since the automotive industry requires epoxy-based structural adhesives to have a high level of high-speed impact resistance. Hence, we used phenol-terminated polyurethane (PTPU) as a toughening agent for epoxy adhesives and compared the results with those that were obtained with carboxyl-terminated butadiene acrylonitrile copolymer (CTBN). The high-energy impact resistance of the epoxy adhesives was measured by the impact wedge-peel (IWP) test, and the shear strength was measured by the single lap joint test. As a result, the 20 wt % PTPU-modified epoxy adhesive showed remarkably higher total absorbed energy (25.8 J) during the IWP test and shear strength (32.3 MPa) as compared with the control epoxy adhesive (4.1 J and 20.6 MPa, respectively). In particular, the total absorbed energy of the PTPU-modified epoxy adhesive was much larger than that of the CTBN-modified epoxy adhesive (5.8 J). When more than 10 wt % PTPU was added, the modified epoxy adhesives showed stable crack growth and effectively transferred external stress to the substrate. These results were explained by changes in the glass transition temperature, crosslinking density, and morphology due to the toughening agents.

scholarly journals Effects of Epoxy Adhesive Layer Thickness on Bond Strength of Joints in Concrete Structures

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2396 ◽  
Author(s):  
Jaeheum Yeon ◽  
Yooseob Song ◽  
Kwan Kyu Kim ◽  
Julian Kang
Keyword(s):  
Shear Strength ◽  
Concrete Structures ◽  
Adhesive Layer ◽  
Epoxy Adhesive ◽  
Experimental Investigations ◽  
Strength Development ◽  
Epoxy Adhesives ◽  
Repair Materials ◽  
Metal Plates ◽  
Bond Layer

In the construction field, adhesives are frequently used to improve adhesion between two objects. Epoxy adhesives are applied as long-term solutions, improving the bond between repair materials and existing concrete structures. Experimental investigations of the relationship between the thickness of an adhesive layer and its shear strength have been conducted by a number of industries outside of the construction sector. However, that research used metal plates as adherends when determining the shear strengths of epoxy adhesives. Therefore, this study examines epoxy adhesives’ shear strength development when applied to concrete adherends. The test results show that the thickness of the bond layer did affect shear strength development in the epoxy adhesives examined.

scholarly journals Prediction of Lap Shear Strength and Impact Peel Strength of Epoxy Adhesive by Machine Learning Approach

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 872
Author(s):  
Haisu Kang ◽  
Ji Hee Lee ◽  
Youngson Choe ◽  
Seung Geol Lee
Keyword(s):  
Machine Learning ◽  
Shear Strength ◽  
Linear Correlation ◽  
Peel Strength ◽  
Epoxy Adhesive ◽  
Data Sets ◽  
Ann Model ◽  
Lap Shear Strength ◽  
Lap Shear ◽  
The Impact

In this study, an artificial neural network (ANN), which is a machine learning (ML) method, is used to predict the adhesion strength of structural epoxy adhesives. The data sets were obtained by testing the lap shear strength at room temperature and the impact peel strength at −40 °C for specimens of various epoxy adhesive formulations. The linear correlation analysis showed that the content of the catalyst, flexibilizer, and the curing agent in the epoxy formulation exhibited the highest correlation with the lap shear strength. Using the analyzed data sets, we constructed an ANN model and optimized it with the selection set and training set divided from the data sets. The obtained root mean square error (RMSE) and R2 values confirmed that each model was a suitable predictive model. The change of the lap shear strength and impact peel strength was predicted according to the change in the content of components shown to have a high linear correlation with the lap shear strength and the impact peel strength. Consequently, the contents of the formulation components that resulted in the optimum adhesive strength of epoxy were obtained by our prediction model.

Effect of nanoalumina in epoxy adhesive on lap shear strength and fracture toughness of aluminium joints

2019 ◽  
Vol 97 (2) ◽  
pp. 117-139 ◽  
Author(s):  
Sunil Kumar Gupta ◽  
Dharmendra Kumar Shukla ◽  
Dhake Kaustubh Ravindra
Keyword(s):  
Fracture Toughness ◽  
Shear Strength ◽  
Epoxy Adhesive ◽  
Lap Shear Strength ◽  
Lap Shear

scholarly journals Microstructure and mechanical properties of an ultrasonic spot welded aluminum alloy: the effect of welding energy

2021 ◽  
Author(s):  
He Peng ◽  
Daolun Chen ◽  
Xianquan Jiang
Keyword(s):  
Shear Strength ◽  
Aluminum Alloy ◽  
Cyclic Loading ◽  
Crack Growth ◽  
Failure Mode ◽  
Spot Welding ◽  
Energy Levels ◽  
Lap Shear Strength ◽  
Pull Out ◽  
Lap Shear

The aim of this study is to evaluate the microstructures, tensile lap shear strength, and fatigue resistance of 6022-T43 aluminum alloy joints welded via a solid-state welding technique–ultrasonic spot welding (USW)–at different energy levels. An ultra-fine necklace-like equiaxed grain structure is observed along the weld line due to the occurrence of dynamic crystallization, with smaller grain sizes at lower levels of welding energy. The tensile lap shear strength, failure energy, and critical stress intensity of the welded joints first increase, reach their maximum values, and then decrease with increasing welding energy. The tensile lap shear failure mode changes from interfacial fracture at lower energy levels, to nugget pull-out at intermediate optimal energy levels, and to transverse through-thickness (TTT) crack growth at higher energy levels. The fatigue life is longer for the joints welded at an energy of 1400 J than 2000 J at higher cyclic loading levels. The fatigue failure mode changes from nugget pull-out to TTT crack growth with decreasing cyclic loading for the joints welded at 1400 J, while TTT crack growth mode remains at all cyclic loading levels for the joints welded at 2000 J. Fatigue crack basically initiates from the nugget edge, and propagates with “river-flow” patterns and characteristic fatigue striations. Keywords: aluminum alloy; ultrasonic spot welding; EBSD; microstructure; tensile strength; fatigue

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