contact

[mambo5]

hi, i am modelling composite structure (concrete slab on a steel I-beam), i not really understand/sure whether the 'contact' will need to be used in my modelling? in fact i not really understand about the function/purpose/meaning of 'contact'. does it meant, the contct between 2 (or more) elements surface, in my case would be the bottom of the concrete slab and the top flange of the I-beam. Please advise.

 

[rstupplebeen]

If the concrete is just laying on the I-beam or may touch during the analysis then contact would be appropriate. If the concrete was glued to the I-beam a tied constraint could be appropriate instead. Or have 1 part and section it at the junction and apply 2 materials. Hope this helps.

Rob Stupplebeen

 

[mambo5]

in reality, there would be steel-sheet below the concrete slab then the steel sheet will be placed on the I-beam, steel-studs will be used (through concrete, steel-sheet and I-beam) to connect the 3 elements.

 

[rstupplebeen]

Without any more details like relative thicknesses I assume that the sheet is thin and can be neglected. As a quick hand calc to determine if the sheet can be neglected do an "I" calc with and without the sheet assuming a perfect bond between the parts. If the error associated with neglecting the sheet is acceptable then go with it. I would use contact between the concrete and the I-beams and discrete connectors where the steel studs would be. When post processing the results look at the maximum loads carried by the connectors to determine if the connection would fail. Hope this helps.

Robert Stupplebeen

 

[mambo5]

rstupplebeen,

possible to send me a *.inp file with simple 'contact' function, so that i will know how/when to apply that. many thanks.

 

[mambo5]

can i use single part (shell element) to creat the model, then partition them and apply different material properties on them. so that i can prevent to use the complex contcat function, do you think this will work? please advice.

 

[rstupplebeen]

http://www.eng-tips.com/viewthread.cfm?qid=204862

Hope this helps.

Rob Stupplebeen

 

[mambo5]

thanks Rob.