Ultrasonic welding (UW) is a well-established technique for joining thermoplastic composites and has recently been utilized in the aerospace automotive industries. In case of thermoset (TSCs), polymer-based material placed at interface called an energy director (ED) required. The choice coupling layer linked to several requirements, such as processing temperature, high adhesion (TSCs) adherend ...

Adhesively bonded joints are commonly used in airframe structures due to their superior strength to weight ratio, lower maintenance cost, and longer service life. The bonded joint reliability is affected by the environmental conditions, such as moisture, temperature, and service environment. In this study, the role of contamination during the bonding process on the joint mechanical integrity is...

In the complex engineering structures the use of bonded joints are often preferred to more traditional methods of fabrication such as bolts and welds since they are lighter and spread load more evenly. For determination the durability of such structures it is necessary to know well the stress field around stress concentrators. At the free edge of bonded joints between the adhesive and the adher...

The work described here is an uHrasonies based experimental study which aims to address the lack of a reliable technique for detecting strength loss in adhesive joints after exposure to hot wet environments. This is manifested as a change in the failure mode of an adhesive system from a cohesive failure in the as-made condition, that is failure through the adhesive, to an adhesive failure, fail...

model (CZM). Using stability analysis of linear equations governing plane strain quasi-static deformations of an elastomer, we find (i) a non-dimensional number relating the elastomer layer thickness, h, the long term Young's modulus, E1, of the interlayer material, the peak traction, Tc, in the CZM bilinear tractionseparation (TS) relation, and the fracture energy, Gc, of the interface between...

The effect of the hydrophobic group content in gelatin on the bonding strength of novel tissue-penetrating tissue adhesives was evaluated. The hydrophobic groups introduced into gelatin were the saturated hexanoyl, palmitoyl, and stearoyl groups, and the unsaturated oleoyl group. A collagen casing was employed as an adherend to model soft tissue for the in vitro determination of bonding strengt...

This work reports the outcomes of an extensive experimental campaign on the retrofitting of masonry walls by means of carbon fiber reinforced polymer (CFRP) sheets, carried out at University of Applied Sciences (UAS) Fribourg. In the first stage, static-cyclic shear tests were conducted on the masonry walls, followed by a second stage of tensile tests on alternative configurations of mechanical...

The existing analytical solutions for the peeling and shearing stresses in polymeric adhesively bonded structures are either too inaccurate or too complex for adoption by practicing engineers. This manuscript presents a closed-form solution that is reasonably accurate yet simple and concise enough to be adopted by practicing engineers for design analysis and exploration. Analysis of these conci...