Despite no support, some nodes generate reactions

Question:

I came across an issue while modelling a cable bridge. I found that the reactions calculated from Midas and the calculation made by hand was inaccurate. I have given a few point loads on the bridge. But though I didn’t give any support reactions some forces are shown on z direction. You will notice it when you look at the model. Please be kind enough to clarify them



Answer:Dear User,

The nodal loads ( Fz) are assigned on the truss elements in transverse direction.
Truss elements can resist loads only when loaded along the longitudinal direction. ( i.e axial direction).

Hence you get reactions in FZ direction for load case LL .
Also the nodes do not intersect the element on which they are present. This again would affect the analysis.
You can divide them using Node/Element > Divide option.
Creation date: 10/31/2017 3:14 AM ()      Updated: 10/31/2017 12:53 PM ()