# Axial force in bolted simulation "force of connector"

Discussion created by Francesco Porcari on Oct 21, 2019
Latest reply on Oct 23, 2019 by Simon Yang

Hello to all,
I'm trying to figure out how the bolt connector works in Solidworks Simulation.

I modeled two simple beams with end plate, where there are 4 holes for M16 bolts.

In Solidworks Simulation, one end of the beam is fixed and to the other is applied an axial force of 40kN.

In order to have no doubts about the calculation, I set the "Known tensile stress area" option with the mentioned area set to 144 mm^2. The chosen axial preload is 63347 N.

By calculating the rigidity of the screw and the plates, I obtain a load distribution factor C = 0.36.

So I would expect a tensile force on each bolt of 63347 + 40/4 * 0.36 = 66947 N, instead the software records the following values, if I check the option "Show the force of the connector":
- 63428 N (as in the screenshot)
- 63450 N
- 63438 N
- 63425 N

Why does the software give me different values? Thanks for your help! 