1 Topic by ateIbb (edited by ateIbb 2012-08-27 15:25:39)

  • Registered: 2012-08-27
  • Posts: 2

Topic: Direction of Forces - Neglecting Components in Calculation

Hallo,

I have following problem (I reduced the system so that I can exclude other sources that make problems):

My macroelement is a cube in 3d, which is rotated in an angle of 45° according to the global coordinate system.
When I bring up a force perpendicular to a surface, ATENA only takes in account the forces in one global direction (for example global x-direction).
I support the cube at the opposite surface. Thus I get an excentric distribution of reaction forces and the value is force times cos/sin(angle).
Actually the force should go smoothly form Surface A (Force) to Surface B (Support).

What does following warning mean (can that cause my problem)
(*)    Warning: Zero RHS vector

Did I miss something?

Quote Post 1

  • dpryl
  • CC software developer
  • Offline
  • Registered: 2007-07-13
  • Posts: 1,107

Re: Direction of Forces - Neglecting Components in Calculation

Dear ateIbb,
1. the warning about Zero RHS vector means the system right hand side is 0. This means no external forces being applied in the load step producing this message, which is OK for, e.g., thermal or shrinkage load, but not in case of applied forces or prescribed displacements.
Most frequently, this means A. the intended load case is not applied in the load step in question or B. there are conflicting supports and loads, and as supports have priority, the loads are ignored.

2. without seeing your model we can only try to guess what could be wrong. Here, I suspect mixing conflicting loads and supports on one or more of the surfaces. Please check and if you can't localize the problem source, send us your model.

dpryl's Website

Quote Post 2

  • Registered: 2012-08-27
  • Posts: 2

Re: Direction of Forces - Neglecting Components in Calculation

Thank you for your answer!

Today I upgraded Atena to the latest version and everything is alright now.

Quote Post 3