EFFECT EVALUATION OF THE ADHESIVE THICKNESS VARIATION IN SINGLE LAP JOINTS BONDED WITH STRUCTURAL ADHESIVE

The low quality of adhesion performance on polymeric surfaces has forced the development of specific pretreatments able to toughen the interface between substrate and adhesive. Among these methods, atmospheric pressure plasma treatment (APPT) appears particularly suitable for its environmental compatibility and its effectiveness in altering the chemical state of the surface. In this work, an experimental study on adhesively bonded joints realized using polyamide as substrates and polyurethane as the structural adhesive was carried out with the intent to characterize their fatigue behavior, which represents a key issue of such joints during their working life. The single lap joint (SLJ) geometry was chosen and several surface pretreatments were compared with each other: degreasing, abrasion (alone and followed by APPT) and finally APPT. The results show that the abrasion combined with APPT presents the most promising behavior, which appears consistent with the higher percentage of life spent for crack propagation found by means of DIC on this class of joints with respect to the others. APPT alone confers a good fatigue resistance with respect to the simple abrasion, especially at a low number of cycles to failure.

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Strength and Failure Mechanism of Composite-Steel Adhesive Bond Single Lap Joints

Advances in Materials Science and Engineering ◽

10.1155/2018/5810180 ◽

2018 ◽

Vol 2018 ◽

pp. 1-10

Author(s):

Kai Wei ◽

Yiwei Chen ◽

Maojun Li ◽

Xujing Yang

Keyword(s):

Failure Mechanism ◽

Shear Failure ◽

Failure Load ◽

Lap Joints ◽

Adhesive Joints ◽

Adhesive Failure ◽

Interface Failure ◽

Element Analysis ◽

Single Lap Joints ◽

Structural Adhesive

Carbon fiber-reinforced plastics- (CFRP-) steel single lap joints with regard to tensile loading with two levels of adhesives and four levels of overlap lengths were experimentally analyzed and numerically simulated. Both joint strength and failure mechanism were found to be highly dependent on adhesive type and overlap length. Joints with 7779 structural adhesive were more ductile and produced about 2-3 kN higher failure load than MA830 structural adhesive. Failure load with the two adhesives increased about 147 N and 176 N, respectively, with increasing 1 mm of the overlap length. Cohesion failure was observed in both types of adhesive joints. As the overlap length increased, interface failure appeared solely on the edge of the overlap in 7779 adhesive joints. Finite element analysis (FEA) results revealed that peel and shear stress distributions were nonuniform, which were less severe as overlap length increased. Severe stress concentration was observed on the overlap edge, and shear failure of the adhesive was the main reason for the adhesive failure.

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Effect of adhesive thickness and overlap on the behavior of composite single-lap joints

Mechanics of Advanced Materials and Structures ◽

10.1080/15376494.2019.1639086 ◽

2019 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Lorena M. Fernández-Cañadas ◽

Ines Ivañez ◽

Sonia Sanchez-Saez ◽

Ever J. Barbero

Keyword(s):

Lap Joints ◽

Single Lap Joints ◽

Adhesive Thickness

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Effect of adhesive thickness and surface roughness on the shear strength of aluminium one-component polyurethane adhesive single-lap joints for automotive applications

Journal of Adhesion Science and Technology ◽

10.1080/01694243.2016.1170588 ◽

2016 ◽

Vol 30 (17) ◽

pp. 1913-1929 ◽

Cited By ~ 18

Author(s):

Yasmina Boutar ◽

Sami Naïmi ◽

Salah Mezlini ◽

Lucas F. M. da Silva ◽

Mohamed Hamdaoui ◽

...

Keyword(s):

Surface Roughness ◽

Shear Strength ◽

Lap Joints ◽

Automotive Applications ◽

Polyurethane Adhesive ◽

Single Lap Joints ◽

Adhesive Thickness

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Study on the effect of adhesive thickness of single lap joints using acoustic emission and FEA

Insight - Non-Destructive Testing and Condition Monitoring ◽

10.1784/insi.2012.55.1.35 ◽

2013 ◽

Vol 55 (1) ◽

pp. 35-41 ◽

Cited By ~ 4

Author(s):

K Mohamed Bak ◽

K Kalaichelvan ◽

G K Vijayaraghavan ◽

M Dinesh ◽

V Arumugam

Keyword(s):

Acoustic Emission ◽

Lap Joints ◽

Single Lap Joints ◽

Adhesive Thickness

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Shear Strength Prediction of Single Lap Joints Based on Latin Hypercube Method

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.101-102.681 ◽

2011 ◽

Vol 101-102 ◽

pp. 681-684

Author(s):

Long Li ◽

Ping Hu ◽

Wei Dong Li ◽

Xiao Qiang Han

Keyword(s):

Shear Strength ◽

Yield Strength ◽

Failure Load ◽

Lap Joints ◽

Strength Prediction ◽

Predictive Equation ◽

Latin Hypercube ◽

Single Lap Joints ◽

Test Speed ◽

Adhesive Thickness

Adhesive bonded single lap joints are used extensively in the manufacture of automobile structures. However, the joints involve many factors such as the overlap, the adherend thickness, the adherend yield strength etc. Therefore, strength prediction is a controversial issue. In order to quantify the effects of various variables, Latin Hypercube method was used to design the tests of simulation in the present study. The failure load predictive equation involving the factors of the overlap, the adherend thickness, the adherend yield strength, the adhesive thickness, the test speed and the adhesive toughness were achieved. The tests of single lap joints in tension load were carried on; while the results form experiments and formula were compared to verify its validation for strength prediction.

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