I have an assignment where I need to analyze a structure and have it approved according to the Eurocode 3 standard.
It is a rather simple steel frame that serves two functions. It is used for assembling a series/stack of ventilation devices (filters, heat exchanger etc) onto it, and then, once assembled and transported to customer, it is also used for lifting it into place. It is the lifting that is the critical load case that need to be analyzed.
Setting up the model with constraints, material properties, loads etc is pretty easy. I can run it, and I can extract results, such as stress, strain. I can, if necessary, refine the model and solution, to get a more accurate result etc. It has a few bolt connections that can be modeled in more or less detail.
So far so good.
Now I'm trying to figure out how to relate these results; i.e. stresses, strains, displacements, to the Eurocode 3 standard. This is not straight forward. I called a guy at the Swedish Institute for Standards, who are responsible for issuing these standards in Sweden. He could not give me a straight answer. "It sorta depends"... :-/
The standard describes how to introduce so-called partial factors, i.e. safety factors to account for uncertainties regarding loads, geometry, material properties etc. Also this is pretty straight forward. So given that I know these partial factors, I can run my analysis and calculate, say a maximum stress level. How do I then use this stress (or strain or deformation) to determine wether or not my design fulfils the standard. I.e. what is actually the dimensioning criteria that should be satisfied. The standard says, as far as I can see, that the "design value of effect of actions should be less thatn the design value of the resistance"
What the (*f-word*) does this mean???