When I enter setup in the drop test module, I receive many messages saying that elements attached to areas cannot be deleted, use ACLEAR instead. Why does this happen and/or do you know how to suppress these messages? The model seems to be fine after all the messages finish flashing by on the screen.
The problem with this model is that areas on the exterior of the meshed volumes are themselves meshed. Upon entering setup, ANSYS deletes preexisting surface(s) onto which the structure is dropped (say, from previous entry into the drop test module). ANSYS selects the volumes and then executes ALLSEL,BELO,VOLU, then does an inverse select on elements to select the target elements that are to be deleted. The problem with this is that the ALLS,BELO,VOLU does NOT select the shell elements on the exterior of the solids, so that they are selected by the inverse select command that follows. Setup then attempts to delete the selected elements, and since the shells are associated with the area, they cannot be deleted and you get a nuisance warning message for each shell.
WORKAROUND: To suppress these nuisance warnings when meshed areas and volumes are attached in your model, invoke a simple macro in the preprocessor before entering set up in the drop test module. The macro contains the following 3 commands:
! macro file name: before_dt.mac
This should greatly reduce time spent writing messages to the error file and also prevents appearance of warning messages to the screen.
After entering the drop test module you may restore default program behavior by invoking the foloowing macro:
! macro file name: after_dt.mac
For convenience, you can add these two macros on the toolbar: