Welcome to 3DCADForums

Join our CAD community forums where over 25,000 users interact to solve day to day problems and share ideas. We encourage you to visit, invite you to participate and look forward to your input and opinions. Acrobat 3D, AutoCAD, Catia, Inventor, IronCAD, Creo, Pro/ENGINEER, Solid Edge, SolidWorks, and others.

Register Log in

What is the role of "Size" and "Sag" in Catia analysis


Hello all after a while :)

I recently went back to Catia from Rhino because of a requirement, though I will never leave Catia. Using Rhino is simpler with less complexity than Catia and it has its own particular usage. I mostly chose Rhino because of participating in a freelancing web that offered some projects relative to Rhino.

Anyhow, I recently had to think about designing a ramp (150 mm height , 790 mm length and 750 mm width) that someone sent to the web to be designed for a lift truck with weight of 7 Tons. I had to go back to Catia to calculate the resistance of a steel sheet against the pressure of 2500 Kg (every wheel of the truck). I drew a piece of the sheet ( 10*400*250 mm) and transferred it to the Analysis section and tried to realize what its behavior will be against the pressure.

In the Analysis section I encountered two factors; "Size" and "Sag". I really couldn't understand what the role of these two factors is in the calculations and the level of the deformation of the piece of the steel sheet. Which numbers I should choose for Size and Sag to show the real resistance (tolerance) of the sheet and the real level of its deformation. In fact, I need to understand the role of these two factors for calculating the real behavior of the metal things against a specified pressure. This picture that I took from the screen may helps:



"Size" - is length of one side of a tetrahedron in a mesh. If there's less size of it when accuracy of your result will be better.
"Sag" - is a maximum deflection of one curved side of tetrahedron with curved geometry.