Adhesive thickness effects of a ductile adhesive by optical measurement techniques

• Type: Article in International Scientific Journal
• Date: 2015

Authors

Campilho, RDSG (Author) Other; Moura, DC (Author) Other; Banea, MD (Author) Other; da Silva, LFM (Author) FEUP

Journal

Title: International Journal of Adhesion and Adhesives

Vol. 57

Pages: 125-132

ISSN: 0143-7496

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 21 Citations

Scopus - 42 Citations

Scientific classification

FOS: Engineering and technology > Chemical engineering

Other information

Authenticus ID: P-00A-2KH

DOI: 10.1016/j.ijadhadh.2014.12.004

Abstract (EN): Adhesive bonding is an excellent alternative to traditional joining techniques such as welding, mechanical fastening or riveting. However, there are many factors that have to be accounted for during joint design to accurately predict the joint strength. One of these is the adhesive layer thickness (t(A)). Most of the results are for epoxy structural adhesives, tailored to perform best with small values of t(A), and these show that the lap joint strength decreases with increase of t(A) (the optimum joint strength is usually obtained with t(A) values between 0.1 and 0.2 mm). Recently, polyurethane adhesives were made available in the market, designed to perform with larger t(A) values, and whose fracture behaviour is still not studied. In this work, the effect of t(A) on the tensile fracture toughness (G(n)(c)) of a bonded joint is studied, considering a novel high strength and ductile polyurethane adhesive for the automotive industry. This work consists on the fracture characterization of the bond by a conventional and the J-integral techniques, which accurately account for root rotation effects. An optical measurement method is used for the evaluation of crack tip opening (delta(n)) and adherends rotation at the crack tip (theta(o)) during the test, supported by a Matlab (R) sub-routine for the automated extraction of these parameters. As output of this work, fracture data is provided in traction for the selected adhesive, enabling the subsequent strength prediction of bonded joints.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8