Work Package 5

The main aim is to assess the short and long term integrity of dissimilar material joints in terms of their mechanical (strength, fatigue, impact) and environmental performance (corrosion). based on the results, a design optimisation of the novel proposed joints will be carried out simultaneously with appropriate quality control using the newly developed NDT and NDE techniques.

Task 5.1 – NDT testing of sample before joint integrity assessment

NDT testing of the samples to be used for the mechanical property and fracture mechanics assessment have to be performed, telling which samples are defective and which are not according to NDE.

Task 5.2 – Mechanical property assessment of dissimilar metal joints

The work performed within this task will include a number of mechanical property testing to include, static strength, fatigue and impact tests. Most of this work will be performed at NTUA but some samples will be supplied to UNEW for evaluation.

Task 5.3 – Mechanical property assessment of metal/composite joints

A microstructural investigation of the joints will be carried out through optical microscopy and scanning electron microscopy (SEM) to fully characterise the joint interface prior to mechanical testing. As a first means of assessment of joint quality, pull off tests will be carried out to assess the strength of adhesion of the composite to the metal substrate in terms of the volume fraction and orientation of the carbon nanotubes either in the form of electrophoretic deposition or interleaved thin veils.

Task 5.4 – Fracture mechanics assessment of the metal/composite interface

This task will undertake the analysis of the stress fields at the interface corner of composite/steel (anisotropic/isotropic) double lap joint to predict failure by using stress intensity based fracture criterion. The analytical results will be compared with experimental results of co-cured lap joints under tensile load condition.

Task 5.5 – Assessment of environmental degradation of dissimilar metal joints

NTUA will investigate the Corrosion behaviour of the produced dissimilar metal alloys will be examined by the following methods:

Electrochemical Impedance Spectroscopy (EIS), Linear Polarization, Tafel and Potentiodymanic Polarization.

 Task 5.6 – Assessment of environmental degradation of metal/composite joints

NTUA will investigate the Corrosion behaviour of the produced dissimilar metal alloys will be examined by the following methods:

Electrochemical Impedance Spectroscopy (EIS), Linear Polarization, Tafel and Potentiodymanic Polarization.