Structural integrity assessment of a full-scale adhesively-bonded bi-material joint for maritime applications

The present study proposes a comprehensive integrity assessment approach for a full-scale adhesively-bonded bi-material joint for maritime applications. The joint represents a cross-section of the bond-line connection of a ship with a steel hull and a sandwich composite superstructure. The full-scale joint consists of a sandwich composite...

Synthesis and characterization of novel eco-epoxy adhesives based on the modified tannic acid for self-healing joints

The aim of this research was to investigate the self-healing potential of damaged Al joints when bonded using novel eco-epoxide adhesives derived from tannic acid (TA). Two eco-epoxy components based on TA, (A) glycidyl ether and (B) glycidyl phosphate ester of TA, were produced. The effect of the eco-epoxy components on the self-healing...

On the influence of the adhesive and the adherend ductility on mode I fracture characterization of thick adhesively-bonded joints

Thicker bondlines along with manufacturing-tolerant and fracture-resistant adhesives are trends visible across different industries, especially maritime. In this work, two contrasting adhesives: an elastic-brittle epoxy-based, and a nonlinear-ductile methyl methacrylate (MMA) are characterized and compared via tensile, compact tension (CT)...

The effect of modified tannic acid (TA) eco-epoxy adhesives on mode I fracture toughness of bonded joints

Two synthesized eco-epoxy components based on TA: (A) glycidyl ether and (B) glycidyl phosphate ester, are used, as a replacement for the Bisphenol A (BPA) based epoxy component, for bonding aluminum (Al) and carbon fiber reinforced polymer (CFRP). Their effect on the mode I fracture toughness (GI) is evaluated by Double Cantilever Beam (DCB)...

Self-healing capability of novel eco-epoxy adhesives based on the modified tannic acid on Al adherends tested in a single lap joint

The aim of this paper is to study the self-healing capability of fractured Al joints bonded with novel eco-epoxide adhesives synthesized from a bio-renewable raw material (tannic acid – TA). Two synthesized eco-epoxy components based on TA, (A) glycidyl ether and (B) glycidyl phosphate ester of TA, were used as a replacement for the toxic epoxy...

Testing mechanical performance of adhesively bonded composite joints in engineering applications: an overview

The development of new adhesives has allowed to expand the application of bonding into the most diverse industrial fields. This review article presents the commonly used experimental methods for the investigation of mechanical performance of adhesively bonded joints in the aerospace, wind energy, automotive and civil engineering sectors. In...

Tailored Adhesion Properties of Acrylate Adhesives on Al Alloys by the Addition of Mn-Al–LDH

The goal of this study was to investigate the effect of the structure of Mn-Al layered double hydroxide (LDH) on the adhesion behavior of composite adhesives on two Al alloys (L3005 and L8079). The composite adhesives were made out of the UV-curing Bisphenol A glycidylmethacrylate/triethylene glycol dimethacrylate (BT) as polymer matrix and the...

Effect of salt spray ageing on the fracture of composite-to-metal bonded joints

This work investigates the effect of long-term environmental exposure on the performance of composite-to-metal bonded joints. Specimens are manufactured using a carbon-fiber reinforced polymer (CFRP) co-bonded to a steel member with epoxy adhesive and aged in a salt spray chamber. The mixed-mode fracture behavior of the non-aged and aged...

Damage assessment of a titanium skin adhesively bonded to carbon fiber–reinforced plastic omega stringers using acoustic emission

This study is devoted to the use of acoustic emission technique for a comprehensive damage assessment, that is, damage detection, localization, and classification, of an aeronautical metal-to-composite bonded panel. The structure comprised a titanium panel adhesively bonded to carbon fiber–reinforced plastic omega stringers. The panel contained...

Improving the adhesion strength of polymers: effect of surface treatments

To improve their adhesion strength, polymeric surfaces are usually modified through different treatments. This study investigates the effect of mechanical, chemical, and energetic treatments on the bonding strength of ethylene propylene diene methylene (EPDM), polyvinyl chloride (PVC), and acrylonitrile butadiene styrene (ABS) materials. Three...

Enhanced Interface Adhesion by Novel Eco-Epoxy Adhesives Based on the Modified Tannic Acid on Al and CFRP Adherends

This paper presents a new process for obtaining eco-epoxide adhesives synthesized from bio-renewable raw material (tannic acid-TA) and used for bonding lightweight materials (aluminum (Al) and carbon fiber reinforced polymer (CFRP). Two synthesized bio-epoxy components based on TA, (A) glycidyl ether and (B) glycidyl phosphate ester of TA,...

Stress analysis of double-lap bi-material joints bonded with thick adhesive

Mechanics of double-lap Steel-to-CFRP adhesively-bonded joints loaded in tension are investigated experimentally using Digital Image Correlation (DIC) and Acoustic Emission (AE), analytically using a one-dimensional closed-form solution and numerically with Finite Element analysis. The double-lap bi-material joints are fabricated of a steel core...

Deformation and damage evolution of a full-scale adhesive joint between a steel bracket and a sandwich panel for naval application

The increasing interest for the application of adhesive joints in naval superstructures motivates researchers to gain an in-depth understanding of the mechanical behaviour and failure mechanisms of these joints. This work reports on an experimental study of the deformation behaviour and damage evolution of a full-scale multi-material joint using...

Damage characterization of adhesively-bonded Bi-material joints using acoustic emission

The aim of the present study is to characterize the damage in bi-material steel-to-composite double-lap adhesively-bonded joints using Acoustic Emission (AE). Two different structural adhesives, a ductile (Methacrylate-based) and brittle (Epoxy-based), were used to bond CFRP skins to a steel core. The fabricated joints were loaded in tension...