Cold-formed (CF) steel built-up sections are increasingly used in low and medium rise buildings as floor decks, joists, bearers and purlins due to their improved structural behaviour. Since the built-up sections are made up of two or more single sections, enhanced bearing capacity are observed. Moreover, second moment of area of these sections are increasing hence these sections are expected to use as longer span beams as well. Even though there are some concerns like production cost and manufacturing processes are available, built-up sections are getting more attention due to these added benefits listed earlier. However, these structural members are often subjected to localised bearing failures due to the application of concentrated, localised loads or reactions. This bearing failure, commonly termed as web crippling, which is one of the critical failure modes of cold-formed members. Therefore, comprehensive understanding on the web crippling behaviour of cold-formed steel built-up sections is necessary to ensure the safe and efficient design.
The overall aim of this research is to investigate the web crippling behaviour of CF steel built-up sections through experimental studies and finite element analyses. This project will enable developing a new design procedure and that could ultimately improve the current standards of design practices for lightweight CF steel built-up sections and enhance their commercial aspects.
The specific tasks of this study are to:
- Perform detailed literature survey on web crippling test methods and finite element model development of CF steel built-up sections
- Conduct full-scale structural tests for carefully selected sections having different section depths in order to investigate the web crippling behaviour of CF steel built-up sections
- Develop Finite element models of optimized CF beams to simulate their web crippling behaviour and capacities
- Obtain the ultimate web crippling capacities using non-linear static/quasi-static analysis based on suitable geometric imperfections and residual stresses
- Validate the finite element model and subsequently, using it for generating a wide range of web crippling data
- Check the suitability of the current design standards for the web crippling capacities of built-up sections using test and finite element results
- Develop new design equations based on the Direct Strength Method for built-up sections with the aid of all the web crippling capacities data
The principal supervisor for this project is Associate Professor Keerthan Poologanathan.
Eligibility and How to Apply:
Please note eligibility requirement:
· Academic excellence of the proposed student i.e. 2:1 (or equivalent GPA from non-UK universities [preference for 1st class honours]); or a Masters (preference for Merit or above); or APEL evidence of substantial practitioner achievement.
· Appropriate IELTS score, if required.
· Applicants cannot apply for this funding if currently engaged in Doctoral study at Northumbria or elsewhere or if they have previously been awarded a PhD.
For further details of how to apply, entry requirements and the application form, see
Please note: Applications that do not include a research proposal of approximately 1,000 words (not a copy of the advert), or that do not include the advert reference (e.g. RDFC22-B/EE/MCE/POOLOGANATHAN) will not be considered.
Start Date: 1 October 2022
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