BEASY Software and Services

 

ABSTRACT

Structure surfaces damaged by corrosion may develop stress concentrations which lead to initiation of cracks and possible crack growth.

Simulation of the galvanic effects leading to corrosion takes account of the properties of the electrolyte as well as the structural materials, to determine electric fields within the electrolyte, attenuation in the return path, and the surface current densities and potentials. If dissimilar materials are present or a CP system is not adequately designed, areas may exist where anodic current occurs on a structural surface, causing mass loss from the surface. The magnitude of the anodic current density, determined from simulation, can be used to determine surface shape change.

Such shape change generally results in indentations, which act as stress-raisers. Simulation to determine magnitude of the stress concentration can identify likely sites for crack initiation. The possibility of crack growth, and the time taken for the growth, can be determined using fracture and crack growth simulation.

This paper explores the combined use of galvanic simulation and fracture/crack growth simulation.

Firstly galvanic simulation is used to investigate the influences of parameters, including electrolyte thickness and conductivity, on rate of corrosion for a galvanic cell caused by a metallic sample in contact with a more noble material. The paper reaches conclusions regarding the type of environment that is likely to produce higher penetration rates and where this might occur.

Secondly, having removed material from the surface (corresponding to corrosion occurring over a given time), fracture simulation is used to evaluate the stress concentration, initiate cracks, determine stress intensity factors, and identify vulnerability to fatigue failure. This crack growth takes into account the corrosion damage and inherently includes local stress concentration due to the damaged surface. In the crack growth simulation, the full crack path and direction are determined along with the fatigue life.

This paper provides a methodology that can be used by design engineers, to identify possible problems on a structure, giving scope to change designs and so reduce possible failures and in-service repair costs. This methodology identifies areas of the structure that have the greatest risk of damage - which may not be obvious without combined corrosion and fracture simulation; and so provides more informed targeting of locations where “what if” fracture mechanics assessments should be applied.

Key words: Corrosion damage, stress concentration, crack growth

To get the full publication please Open the Publication Below

Open Here

Here are a series of case studies for the types of projects BEASY have helped with worldwide.

To download BEASY case studies we require data from you, please fill in the form provided and the material will become available to download


Please note that by submitting these details you are giving us permission to contact you further to validate that the material fully addressed your requirements.
We will not pass your details on to any third party organisations.

Request Information

Follow Us!

Newsletter Sign-up

Areas of Interest

Please note that by submitting this form you are giving us permission to store the details you have entered above in our database system.  We will use this data to add you to our mailing list to receive the monthly BEASY e-newsletters you have selected. You can remove yourself from the e-newsletter mailing list at anytime by choosing the opt-out feature on the e-newsletter. We may also send you literature about BEASY via postal mailings and any other BEASY information and announcements which we think you will find of interest. We will not pass your details on to any 3rd party organisations.

To download BEASY documents we require data from you, please fill in the form provided and the material will become available to download