Dynamic loads not correctly applied in phase with multiple dynamic substeps


ApplicationPLAXIS 2D
Issue status✔ Solved
First Affected VersionPLAXIS 2D AE.00
Found in VersionPLAXIS 2D AE.00
Fixed and Released in VersionPLAXIS 2D 2015.00
Issue #23255
Date created20 April 2015
Date modified24 October 2016

Problem description

During a dynamic calculation the user should set the amount of additional steps and the amount of dynamic substeps such that he/she obtains the desired time step. Also see this related article for more information on this subject: Time step used in dynamic calculation.

For calculations with a dynamic (point or surface) load and more than 1 dynamic substep the results may be incorrect. This is caused by the fact that the dynamic load vector is incorrectly only updated at the start of the first dynamic sub step and not throughout the other dynamic sub steps. To what extend the results are incorrect is dependent on the situation.

Please note that when working with dynamic prescribed displacements (such as for earthquake) simulations the aforementioned issue does not occur.

Solution

When using the PLAXIS 2D AE version it is recommended to explicitly set the dynamic substeps to 1 for the situations when working with dynamic loads.

This issue is solved in the latest 2D2015.00 release.