Tangential behaviour

[Shz713]

Hi all,

I have some truck axle loading modelled as patch load as shown below to load a bridge. For interaction property, I used Tangential Behaviour which is affecting the results significantly.
I know that there would be some friction in reality when the vehicle tyre is on bridge (stationary not moving vehicle), how I can specify that friction here?
Results of load-displacement curve is affected by changing the Tangential behaviour, higher coefficient of friction giving much higher loading (which of course is not realistic). I've been using tangent coefficient of 0.1 for my analysis so far. I appreciate if someone give me some explanations how to specify friction for this case or if friction is needed at all.

Cheers,

Shoot for the Moon, even if U miss, U still land among Stars!

 

[IDS]

If you are modelling a vertical stationary load, why worry about friction factors? The friction factor between tyre and road surface would be 1 or more anyway.

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[Shz713]

I also believe I don't need to put 'penalty' method, instead choose 'friction-less'.
Since the purpose if loading to find collapse load, the patch load is stationary and modeled as rigid body, so putting friction of 1 or higher I found that increases the total load (which is reasonable as the friction is set higher, more force needed to cause collapse).

Shoot for the Moon, even if U miss, U still land among Stars!

 

[IDS]

I don't know Abaqus, but assuming you are applying vertical loads to a horizontal surface, changing the friction factor shouldn't make any difference. It certainly shouldn't increase the load required to cause collapse. This suggests that what your model is actually doing is different to what you described.

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[Shz713]

I agree with you; because the purpose is to increase a known load (in my case a truck load) until collapse occurs (based on plastic and nonlinear formulation I defined). Actually, I am getting more accurate results when friction coefficient is set to <0.3 or is set to frictionless. In the appended file, you see how load-deflection curve is affected by higher values of friction coefficient.

Shoot for the Moon, even if U miss, U still land among Stars!