Verification of deformed shape of knuckle joint. (My first FEA)
Verification of deformed shape of knuckle joint. (My first FEA)
(OP)
This is simulation of knuckle joint with 50KN tensile load on rods. (One end fixed)

Here's how it's assembled, if you don't know what knuckle joint is.
assembly animation mechteacher article
Someone told me it shouldn't deform like this(and the part with two eyes should contract), without explaining why.
Any help would be highly appreciated, I have to present my work tomorrow :(
p.s. I am using Abaqus/standard, ask anything else you might need.

Here's how it's assembled, if you don't know what knuckle joint is.
assembly animation mechteacher article
Someone told me it shouldn't deform like this(and the part with two eyes should contract), without explaining why.
Any help would be highly appreciated, I have to present my work tomorrow :(
p.s. I am using Abaqus/standard, ask anything else you might need.





RE: Verification of deformed shape of knuckle joint. (My first FEA)
Hint: "Someone" doesn't know what he is talking about.
RE: Verification of deformed shape of knuckle joint. (My first FEA)
I performed several more simulations after that(with varying parameters and general contact) here are results if anyone wants to have a look at it and comment. - http://imgur.com/a/xLwK3
RE: Verification of deformed shape of knuckle joint. (My first FEA)
You are aware that the deformation scale factor is not 1?
RE: Verification of deformed shape of knuckle joint. (My first FEA)
I'm looking at the loading on the pin, and I can see that it'd bend only one way (with a tension load), as you've shown.
draw simple FBDs to understand what's happening.
another day in paradise, or is paradise one day closer ?
RE: Verification of deformed shape of knuckle joint. (My first FEA)
You should be able to load each part in isolation to get an understanding of the relative magnitude of all such behaviours to confirm the overall behaviour of the assembly is "sensible" - and you would probably also gain some insight into the possible interaction of the various behaviours, assumptions you have made about the contact interfaces, clearances, friction, etc.
http://julianh72.blogspot.com
RE: Verification of deformed shape of knuckle joint. (My first FEA)
Also, for an improved deformation result, you probably should not have a contact condition between the tang and the clevis (it appears you do now). You need a gap to allow for manufacturing tolerances and to allow it to rotate.
Brian
www.espcomposites.com
RE: Verification of deformed shape of knuckle joint. (My first FEA)
@ESPcomposites Yeah I know but I only have to study linear static simulations.(Plastic deformation comes under non-linear, right?) BTW I have other simulation models which includes all manufacturing tolerances. (Clearance between pin and both eyes/tong/clevis AND clearance between single and double eye.) Deformation in that model looks similar.
RE: Verification of deformed shape of knuckle joint. (My first FEA)