MOSES DIMENSIONS MOSES DIMENSIONS

One of the interesting features of MOSES is that all of the data is stored in the database in a neutral format. When one inputs data, the units are converted to the "computational" units of the program, and when results are reported, they are converted to an output set of units. MOSES is informed of the units the user wishes to employ via the internal command &DIMEN. Since this is an internal command, it takes effect immediately. Thus, one can input a model using different units for various portions. He can also receive reports of results in a unit system different from that which defined the model. The form of this command is:


     &DIMEN, -OPTIONS

and the available options are:



     -DIMEN, LEN, FOR

     -SAVE

     -REMEMBER

The -DIMEN option controls the current program dimensions. Here, LEN is the length unit, which must be either FEET or METERS, and FOR is the force unit. If LEN = FEET, then FOR must be either KIPS, L-TONS, or S-TONS; and if LEN = METERS, then FOR must be either K-NTS or M-TONS. When a &DIMEN command with a -DIMEN option has been issued, MOSES will expect any subsequent input to be consistent with the units specified on the command, and all output will also be consistent. Notice that this scheme allows for the input of the data in a system of units different from the output with the insertion of a new &DIMEN, -DIMEN command.

The last two options allow for temporarily altering the dimensions and returning to the previous ones. In particular, -SAVE instructs the program to save the current dimensions so that when -REMEMBER is used, the ones previously saved will be recalled.

In documenting the use of units, confusion can arise due to the user's choice of force units. To ameliorate this difficulty, when a force which can be either kips, long tons, short tons, metric tons, or kilo-newtons can be used, we denote the force unit as BFORCE and the length unit as either BLENGTH or llength depending on the type of length unit required. Here, when blength is meters, llength will be mm, and when blength is feet, llength will be inches. This notation of blength, llength and bforce will be used throughout the remainder of the manual. In most places, the units required for a given quantity are specified. If they are omitted, they are:

Quantity Units
time - seconds
angles - degrees
temperature - degrees F or degrees C
length - feet or meters
area - ft**2 or m**2
volume - ft**3 or m**3
velocity - ft/sec or m/sec
acceleration - ft/sec**2 or m/sec**2
stress or pressure - ksi or mpa
force - bforce
moment - bforce-blength
weight per unit length - bforce/blength
weight per unit area - bforce/blength**2