assume a steel square rod of a specific size (e.g. 16x16x2000mm). The rod has a small fixed support on both ends.
When you place a load in the middle of the rod it will bend.
It should also bend without a specific load because of its own weight.
Using simscale it does not bend without a specific load. So obviousely the net weight of the object is not taken into calculation? Based on the volume and material properties it should work.
Why does simscale behave like this?
This would fall under the category: Buckling - however this module is not yet implemented into SimScale but you can use a workaround with a nonlinear analysis which mimics the buckling behavior somehow. In this post from my colleague Richard you can find an example on how to approach these kind of problems.
