Post-Processing Rods and Pipes

When a system contains either rod elements or a pipe assembly, commands are available to obtain additional information about the behavior of the rod elements involved. Here, one can look at the configuration of the rod, the forces in the rod, and the stresses and utilization in the rod. If one is interested in a pipe, the value of ROD_NAME discussed below should be &PIPE, otherwise, it should be the name of the rod for which information is desired. At the conclusion of the command, the user will be placed in the Disposition Menu to dispose of the data as he wishes.

To obtain an idea of the behavior of the rod during the process, one can issue one of the commands:

     R_DETAIL, ROD_NAME, -EVENT EVENT_NUMBER

     R_VIEW, ROD_NAME, -OPTIONS

     R_ENVELOPE, ROD_NAME, -OPTIONS

The available options here are:

     -EVENTS, EVE_BEGIN, EVE_END, EVE_INC

Here, EVE_BEGIN and EVE_END are the beginning and ending event numbers for which the results will be computed, and EVE_INC is an event increment.

The first of these commands, R_DETAIL, allows one to look at the situation at all points in the rod at a single event, EVENT_NUMBER. The R_ENVELOPE command yields the minimum and maximum values at all points in the rod over all events between EVE_BEGIN and EVE_END. Finally, R_VIEW, gives the maximum absolute values of the values over the points in the rod as a function of time. At the conclusion of each of these commands, on is placed in the disposition menu. The corresponding form of the REPORT command is:

     REPORT, NAME(1), NAME(2), .... -OPTIONS

The only option available for reporting is:

     -EVENTS, EVE_BEGIN, EVE_END, EVE_INC

and the NAME(i) must be either FORCE or STRESS for R_DETAIL and FORCE, STRESS, or LOCATION for the other two. If no NAMEs are supplied, all reports will be printed.

Most of the quantities are self explanatory, except with stresses. Here, you get the normal axial, bending, torsion, and shear stresses. Also, you get a column for the maximum axial normal force. This is just the combination of the axial and bending at the extreme fibers. Finally there are three utilization ratios: the maximum normal stress divided by the yield stress, the Von Mises stress divided by the yield stress, and a code check of the interaction of hoop stress with normal stress according to RP2A working stress edition.