Questions and discussion for this lecture live here. Fire away by hitting Reply below 
Hello Sean! Thank you very much for the great content of this course. I have a question regarding the value of y that you took. Why did you take 500 mm?
Thank you very much.
Hey Laura,
Great to hear you’re finding the course helpful.
Can you tell me whereabouts in the lecture you’re referring to??
Cheers,
S
Are your choices for worst case load combinations solely based on your judgement?
What is your thought process behind choosing?
Yes, to some degree, you select loading combinations based on engineering judgement, i.e. what loads are applied and what does the structure naturally want to do in response to those loads. For relatively simple structures like this one, it’s relatively obvious that we have two distinct cases to consider (max bending and max axial stresss) but for more complex structures it will not be as obvious and multiple different load combinations will need to be checked.
So, there is no single method or technique we can apply to immediately identify the worst case design loading in most cases. Often, we just need to go through the exploratory exercise of evaluating various load combinations, guided by the relevant code (EC0/1 in this case).
I hope that helps - let me know if not clear.
Seán
Hello Sean, are there any texts with additional information on load combinations / patterns you could refer me to that would help sharpen my judgement? Thanks.
Hi @Jomo_Ndirangu - there are no really good texts that com to mind on this. I would say, don’t get too hung up on the idea that you will be able to reason out the worst case pattern load or combination by just looking at the structure. Sure - for simple structures you can often ‘big brain’ it and work it out, but quite often, it’s just a matter of establishing what are reasonable, realistic or code-prescribed patters of loading and running the numbers.
The IStructE ‘Manual for the design of structures to Eurocode 1 and Basis of Structural Design’ has a little on this - I have the April 2010 version in front of me here and there is some helpful discussion around pattern loading. It’s actually quite a helpful guide to reference for anything to do with loading.
Hope that’s somewhat helpful.
S