For a single-span beam with a uniformly distributed load (M=q*l^2/8) the program doesn't show the moment graphic as a parabola. The table result values are right only for the maximum, but on other locations they are not. What can I do?
There are several divisions to be considered in RSTAB:
1. Member divisions for results tables
To generate member divisions for result values, go to the "Insert" menu and select "Model Data" and "Member Divisions". With this way of division you get the internal forces for example of members in the RSTAB table 4.1 displayed on intermediate points. The graphical output remains unaffected.
2. Member division for graphical representation
The divisions for the graphical result diagram and the determination of extreme values can be checked and modified in the calculation parameters (toolbar menu "Calculate", see picture 1).
A dialog box opens where you can set the value for the "Result diagrams" to define a finer display for the graphic of internal forces (see picture 2).
This division set in the calculation parameters is considered to be global. The longest member serves as orientation. That is why shorter members do not have the same number of divisions but segments that are similar in size.
Therefore, to improve the graphic, it is recommended to apply a finer division of members (point 2).