Prestress Beam Loads 





Enter prestress loads for beams, or modify or delete previously entered loads. The concept of defining the prestress loads in beams is illustrated below. The cable drape is located on a 2D curve passing through 3 eccentric points. It is assumed that the eccentric points are on the beam element's local xz plane. The tension in the cable is assumed to be uniform over the entire length of the drape. For accurate calculation results, after dividing the beam element into four segments, the program uses the following method to calculate equivalent loads on the beam element. 1. Calculate the equation corresponding to the cable drape. 2. Calculate the slope of the cable drape at each intersection at the end of four segments and the cable drape. 3. Shear, moment and distributed load for each segment can be calculated by the following equations:
(a) Beam member subject to a prestress load
(b) Equivalent load acting on a beam element due to a prestress load<Figure 1> Concept of prestress load in a beam element








From the Main Menu select Load > Temp/Prestress > Prestress Beam Loads. 





LoadsRefer to the figure under the Load Type selection field to enter the drape shape and pretension value. Tension: Pretension Force (enter only a positive value) Di: Cable drape in the local ± z direction at the beam element start point (iside N1 end) Dm: Cable drape in local ± z direction at the beam element midpoint Dj: Cable drape in local ± z direction at the beam element end point (jside N2 end) 

