Plane stress or plane strain for Railway Ballast system ?

user8179

Dear All,

I am working on wooden railsleeper analysis.

Using Druker Prager model for Ballast and soils, Initially I assumed 2D Behavior of RailSleeper and Rails was Plane Stress and for Ballast and soil was Plane stress but I recieved Huge diflections in model as you can see in figure 1.

Later I assumed evrything in Plane stress and recieved very small deflection as you can see n figure 2.

Which one is suitable plane stress for entire model or plain strain for soils and ballst and plane stress for sleeper ?

Kindly give sugesstions, thank you.

HuiLiu

In your first model what did you assume for the rest of the part, if you only assumed plane stress for the rail and sleeper? Did you mean you assumed plain strain for the rest instead of plane stress? The deformation doesn't look realistic, is the 2D behavior the only difference between your two sets of models? What about load/BCs etc?

user8179

Hello,

Many thanks for the reply,

I consider Rail,sleeper and railpad as plane stress with thickness / Ballast, sub ballas and soil as plane strain.

Constrained the buttom surface and applied remote force in rails. Material model for Ballast, sub Ballast and soil are Drucker prager base with failure criteria.

All bonds are conatct.

Thank you,

Kind regards,

Naveen Maddela.