Segment locks are used on both polybars and shape bars.
This option is useful when the user needs to create a variable distribution of a shape bar, and, at the same time, keeping constant some of the bar leg lengths.
For example, the concrete member shown below must be reinforced with a shape bar similar to the one in Section A-A.
The distribution from the Top View is variable, but legs A and E must be constant. To obtain this, segments A and E must be locked.
To lock a polybar or a shape bar segment, the user must double-click the bar to display the segment locks.
Next, the user must click the locks to block - in this case, the ones corresponding to segments A and E. Thus the segments will be kept constant, no matter what distribution type is applied to them.
Next, the bar may be variably distributed throughout the Top View. To do this, the user must select the bar, and then access the Create a variable linear distribution... option 
from the Advance Reinforcement toolbar.
In the next step, the user can manually contour the Top View, or can input "C" on the command line, select the formwork of the element and define the distribution orientation.
The distribution is complete. The locked segments may be viewed:
1. Either in a Bar List... 
2. Or with the 3D Reinforcement Viewer 
