POSTTEN is a STRAP postprocessor program that designs posttension beams and slabs in solved STRAP models.
POSTTEN retrieves the analysis results from STRAP, calculates the effect of the prestressing on the model (including losses), and combines all results to calculate the stresses, etc.
If the prestressing is done on several distinct model that represent intermediate stages of construction, the stages must be defined in STRAP geometry. These 'STRAP stages' are then assigned to the relevant design stages in the POSTTEN module.
For example:
The user has flexible and powerful tools for defining the number of cables and their geometry in the beam section so that all stresses are within the limits.
Each cable may consist of a series of straight segments and parabolas starting and ending anywhere along the span.
 Bonded or unbonded cables may be designed.
 Jacking sequence may be specified.
The program calculates the following:
Losses:
 Accurate claculation of all loss types (creep, shrinkage, etc) including the effect of prestressing at stages. The losses are calculated using a timesteps method.
Ultimate Moment:
 The capacity is calculated for each section using a straincompatibility method, including any regular reinforcement.
Shear:
 Shear capacity is calculated along the length of the span using either the "truss model" or the "inclined struts model", according to the selected design code
Deflections: (beams only)
 Deflections are calculated either by the effective section properties method or by integrating the curvature along the span.
All results are calculated fror userspecified time intervals, Capacities are compared to the actual forces/moments at every section along the span.
Codes:
Eurocode 2, BS8100, BS5400, ACI318, CSA A23.3. AASHTO.
