3 Point Bending in Static Structural & Explicit Dynamics
Hello guys,
I have a problem about 3 point bending case which i created in static structural. The problem is when i apply displacement (z= 14 mm) in z direction and support two ends with displacement constraint (x, y = free, z = fixed) plate did not deform in x direction. But when i looked theory of bending moment, theory said that it must be deform in x direction. After that i did another analysis in explicit module, plate deformed.
I add a picture both of analysis. So if you can help me i really appreciate it.
Note: i used same boundary conditions both static and explicit
analyzes
Best Answer

peteroznewman Member
Static Structural analysis uses the small displacement assumption. That means that a beam does not deform along the x axis when you displace it in z.
Explicit Dynamics analysis does not use the small displacement assumption, so a beam bending in z will foreshorten in x.
To see this effect in Static Structural, under Analysis Settings, turn on Large Displacement. You may notice that the solution takes longer, which is why the default is to be off. You may find that the solution does not converge, since the boundary conditions don't constrain all six rigid body displacements. To fix that, turn on Weak Springs under the Analysis Settings.
Answers
@emreyildirim23
Static Structural analysis uses the small displacement assumption. That means that a beam does not deform along the x axis when you displace it in z.
Explicit Dynamics analysis does not use the small displacement assumption, so a beam bending in z will foreshorten in x.
To see this effect in Static Structural, under Analysis Settings, turn on Large Displacement. You may notice that the solution takes longer, which is why the default is to be off. You may find that the solution does not converge, since the boundary conditions don't constrain all six rigid body displacements. To fix that, turn on Weak Springs under the Analysis Settings.
@peteroznewman Thank you so much for your help, my problem is solved now.