What's the significance of using - values for DX DY DZ direction cosines, when deflection results are all positive regardless.
The direction of the load is very important. The loads may be out or phase and this has to be considered. The applied direction will affect the results and must be considered. The results are reported as +ve only in the report, but the phase and value can be seen in the Time History Post Processor.
Dynamic "Time History" Analysis