The Plaxis Output program uses smoothing techniques to obtain “nice” plots. In essence this means that values from stress points are extrapolated to the nodes and within the nodes the extrapolated values (coming from all adjacent elements) need to be averaged to obtain smooth and continuous plots.
However it was recently found that structural forces plots made for the following situations were not correctly smoothed:
An example where these smoothing issues occur is shown below.
Bending moments in curved plate due to point load, the plot however shows a non-smooth result due to the mentioned issues.
This behaviour has been improved in PLAXIS 3D AE.00 and now resolved in PLAXIS 3D 2017.01.
Plaxis recommends users to also inspect the tabulated output and not to rely only on the plots.
Users may also make use of the menu item View > Use result smoothing. When this toggle is deactivated no smoothing at all is used. By inspecting the unsmoothed plot and the smoothed plot users may get an impression if smoothing is applied correctly or not in their situation.