PhD on the reuse of steel bridge members with fatigue damage

Are you eager to work on the reuse of steel bridge elements which experienced fatigue damage during their service time? In a world with finite resources and limited and slow natural renewal, we must preserve and conserve what is already there. Nevertheless, growth and the desire for creating something new continue to shape human activity and facilitate the preservation or even the desired expansion of the quality of life. This project aims at reusing components from existing steel and steel-concrete composite bridges as components in new bridge and building structures, thereby contributing to a fully circular economy.

The central question for this PhD study is: Can we reuse steel bridge members in new structures? How do we limit the impact of deconstruction? How do we repair these members in case they are damaged? How is this repair effective?
To answer these questions, you will use questionnaires to ask experts, perform experiments, and develop prediction models.
You will focus on the effect of deconstruction on the structural strength, stability, and fatigue life of reused components. Your goal is to develop a set of metrics that aim at quantification of the effect of selected deconstruction methods on the structural reliability of deconstructed elements.

As a part of your project you will make a selection of repair and improvement techniques suitable for the rehabilitation of damaged welded and bolted joints typical for bridge structures. Assisted by finite element modelling, existing techniques are selected on the basis of their effectiveness and considering different levels of fatigue damage. Hence you will be able to identify the repair methods. Depending on the selected repair method, you will focus on the determination of the uncertainties and the performance related to the repair of connections.

To validate your models you will execute fatigue tests under constant and variable amplitude loading on a selected welded joint. The main goal of these tests is to assess the fatigue strength and remaining fatigue lifetime after repair. During the tests you will monitor fatigue damage development with different sensors, hence measuring the fatigue behaviour at the repair location and the extended component lifetime. Ultimately, you will develop and deploy advanced models for an accurate estimation of the remaining fatigue life of reused bridge components based on fracture mechanics incorporating short crack growth. The tests will be used to validate these models.

The knowledge that you develop is crucial for a safe prolonged use of cyclically loaded steel structures such as bridges or crane runways. As such, it helps in creating a sustainable future.

You will benefit from, and contribute to, the acknowledged forefront position in fatigue life prediction of our Steel Structures chair. You will use the experimental facilities of our structures lab.