The influence of dual adhesive in single lap joints on strength and energy absorption

2021 ◽  
Author(s):  
Przemysław Golewski ◽  
Tomasz Sadowski:
Keyword(s):  
Energy Absorption ◽  
Lap Joints ◽  
Single Lap Joints

An Assessment of the Impact Performance of Bonded Joints for Use in High Energy Absorbing Structures

1985 ◽  
Vol 199 (2) ◽  
pp. 121-131 ◽  
Author(s):  
J A Harris ◽  
R D Adams
Keyword(s):  
Energy Absorption ◽  
Joint Strength ◽  
High Energy ◽  
Lap Joints ◽  
Impact Performance ◽  
Single Lap Joints ◽  
Epoxy Adhesives ◽  
Energy Absorbing ◽  
The Impact ◽  
Spot Welded

Using an instrumented impact test, the strength and energy absorption of bonded single lap joints have been measured for single lap joints with four epoxy adhesives and three aluminium alloy adherends. Compared with the static values, joint strength is not significantly affected by the high loading rates. Energy absorption is large when joint strength is sufficient for plastic deformation to occur in the adherends prior to failure, which is only the case for certain adherend/adhesive combinations. Spot welded joints are shown to be inferior in performance in the tests. The effect of loading rate on bonded joint strength has been analysed using a non-linear finite element method, from which predictions of joint strength in keeping with the experimental results have been obtained. Crush tests carried out on open-ended cylinders have been used to simulate the impact behaviour of an energy absorbing structure. Similar performance was observed for cylinders with either bonded or spot welded longitudinal seams, although the large deformations in the crumple zones led to some debonding and weld fracture.

scholarly journals Experimental Study of the Influence of the Surface Preparation on the Fatigue Behavior of Polyamide Single Lap Joints

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1008
Author(s):  
Francesco Musiari ◽  
Fabrizio Moroni
Keyword(s):  
Experimental Study ◽  
Fatigue Behavior ◽  
Atmospheric Pressure Plasma ◽  
Surface Preparation ◽  
Lap Joints ◽  
Polymeric Surfaces ◽  
Adhesively Bonded Joints ◽  
Single Lap Joints ◽  
Number Of Cycles ◽  
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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