Equivalent sandwich thickness
Equivalent sandwich thickness
(OP)
Hi,
I'm trying to calculate the equivalent thicknesses of the elements in a composite sandwich compared to a steel plate with steel stiffeners (three types of stiffener: flatbar, tbar and angle)
How do I do this?
Krish
I'm trying to calculate the equivalent thicknesses of the elements in a composite sandwich compared to a steel plate with steel stiffeners (three types of stiffener: flatbar, tbar and angle)
How do I do this?
Krish






RE: Equivalent sandwich thickness
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Equivalent sandwich thickness
I need to compare the bending stiffness (flexural rigidity).
RE: Equivalent sandwich thickness
You need to work the "I" value out for each built up section using the parallel axis theorem have a look at this site, (you might have to scroll down a bit)
http:/
desertfox
RE: Equivalent sandwich thickness
I have looked at the approach of using a Uneven I-beam (http://ww
If you can I would we very greatful if you could take a quick look at the calculation in the excel sheet?
kind regards
Kristoffer
RE: Equivalent sandwich thickness
What is the figure to the right of the uneven I beam.
I'll have a look and come back later.
desertfox
RE: Equivalent sandwich thickness
I am very greatful for you help.
Krish
RE: Equivalent sandwich thickness
If the uneven "I" beam is all steel then Your spread sheet for the figure on the left is ok.
You only need the "I" value for the beam which you have worked out, at that stage you don't need to multiply by E unless your going to work out the deflection.
The figure on the right I cannot clarify because I am not sure what you have done, however if you have two different materials sandwich together the first thing you need to do is convert one of the materials into the equivalent of the other ie steel-plastic-steel you need to convert the plastic to the equivalent steel section or vice versa.
http://www.freestudy.co.uk/c105/t6.pdf
The link should provide how to do the above you need to scroll to page 11
desertfox
RE: Equivalent sandwich thickness
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Equivalent sandwich thickness
RE: Equivalent sandwich thickness
If you change the depth then the bending assumptions used in developing the transformed section do not apply.....
The reason I make this caution is that the question was about determining equivalent "thicknesses" which I take to mean the section depth.......
Ed.R.
RE: Equivalent sandwich thickness
Thats a fair point however if he follows the link I posted he won't make that mistake.
desertfox
RE: Equivalent sandwich thickness
To explain: I'm comparing a SPS panel with a stiffened steel panel. What I want to find out is what thicknesses for the steel-faces and the polymer-core can be used for the SPS panel to get equivalent flexural rigidity as the stiffened steel panel.
I see now I probably should have written this in the first post. Sorry for this.