Viewing the design results
In order to create a design, we must first have concluded an analysis.
 | In the PRE-Stress application, the “design” stage calculates the capacities of a beam sufficient to address the calculated loads. Therefore, designing without the analysis stage cannot produce a meaningful result. To view the design results, go to the context selector and click on Design. The loadcases will be shown, with the most significant control of the utilization ratio (on a per-section basis) displayed as contiguous lines along the beam. The sidebar will allow you to toggle various visualization methods, and to exaggerate or reduce the representation of deformation, although the actual values will remain unaffected. Through the project tree handler, you can choose to view of all load combinations simultaneously or one at a time. When in Design mode (i.e. viewing design results), the Results option appears as a new menu, allowing you to visualize various factors related to design. |
Firstly, the Utilization Colors option allows the user to set the colors used in the graphical representation of design results.
Utilization Table lets the user view the Utilization Ratios of the load combinations.
Several more extensive tables provide information on bending, shear, stress, and other factors.
Bending, SLS
The bending table shows various bending data at a position along the axis of the beam specified in the Section column.
SLS elements use the symbols below:
| Symbol | Unit | Description |
|---|---|---|
| Md | kNm | Moment |
| Ni | kN | Prestressing force |
| Mi | kNm | Moment due to prestressing force |
| σc,top | MPa | Concrete stress top1) |
| σc,btm | MPa | Concrete stress bottom1) |
| Crack stadium | - | I (uncracked), II (cracked) |
| σs,top | MPa | Reinforcement stress top |
| σs,btm | MPa | Reinforcement stress bottom |
| Mcr | kNm | Moment at point of cracking |
| wk | mm | Crack Width |
| z | mm | Deflection |
1) If the concrete stress is above the cracking stress, the linear concrete stress before the cracking check is shown.
Example of result-table (Bending, SLS):
Bending, ULS
ULS elements use the following symbols:
| Symbol | Unit | Description |
|---|---|---|
| Nd | kN | Normal force |
| Md | kNm | Moment due to loads |
| Mu | kNm | Bending moment capacity |
| Md / Mu | - | Utilization |
| z | mm | Internal lever |
| x | mm | Compression zone height |
| εc | ‰ | Concrete strain |
| εs | ‰ | Steel strain |
| σs,top | MPa | Reinforcement stress top |
| σs,btm | MPa | Reinforcement stress bottom |
| σsc | MPa | Stress in the most compressed (or least tensile) reinforcement bare/wire |
| σst | MPa | Stress in the most tensile (or least compressed) reinforcement bare/wire |
Example of result-table (Bending, ULS) for hollowcore elements:
Shear
Shear values only apply to ULS load combinations.
There are two different tables, if the element is calculated with or without stirrups.
Shear, without stirrups
Some results will only show up depending on the structure or loads. For instance will only torsion-related results show up in the table if atleast one load has been defined with an excentricity, or hollowcore elements has atleast one core filling.
| Symbol | Unit | Description |
|---|---|---|
| Vd | kN | Shear design force |
| Td | kNm | Torsion design moment (conditional) |
| VRd | kN | Final shear design capacity |
| Vd / VRd | - | Utilization with regard to concrete shear capacity |
| VRd,max | kN | Maximum shear capacity |
| Vcw | kN | Capacity due to web shear failure |
| Vcb | kN | Capacity due to bend shear failure |
| Vp | kN | Shear capacity increase/decrease due to normal force |
| Vi | kN | Shear capacity increase due to variable section depth |
| Vcfc | kN | Shear capacity of core fillings (conditional, hollowcore only) |
| VEtd | kN | Shear capacity decrease due to torsion (conditional, hollowcore only) |
| bw | mm | Web width at neutral layer (accumulated) |
| d | mm | Effective depth |
Example of result-table (Shear, ULS, without stirrups):
Shear, with stirrups
Shear values for stirrups have different notation:
| Symbol | Unit | Description |
|---|---|---|
| VSd | kN | Shear design force for stirrups |
| V' | kN | Shear field force, used for design of stirrups |
| VRd,s | kN | Shear design capacity for stirrups |
| V' / VRd,s | - | Shear utilization for stirrups |
| VRd,max | kN | Maximum shear capacity |
| (Asw / s)cur | mm2/m | Applied (current) stirrup reinforcement area |
| (Asw / s)req | mm2/m | Required stirrup reinforcement area |
| (Asw / s)req min | mm2/m | Minimum stirrup reinforcement area |
| bw | mm | Web width |
| z | mm | Internal lever |
Example of result-table (Shear, ULS, with stirrups):
Crack width
Crack width results are only available for SLS
| Symbol | Unit | Description |
|---|---|---|
| Crack stadium | - | I (uncracked), II (cracked) |
| A | m2 | Effective area of cross-section |
| I | m4 | Effective moment of inertia |
| ζ | - | Ratio between cracked and uncracked cross-section |
| Mcr | kNm | Moment at point of cracking |
| As,min | mm2 | Minimum longitudinal reinforcement area required |
| As,curr | mm2 | Current longitudinal reinforcement area |
| sr,max | mm | Maximum distance between cracks |
| wk | mm | Crack width |
Example of result-table (Crack width):
Topping joint
For the case of active topping, separate bending and shear tables are shown. In addition, a table showing results pertaining the joint between the beam and topping is available.
| Symbol | Unit | Description |
|---|---|---|
| Vd | kN | Shear design force |
| Fjoint | kN/m | Joint force |
| ff | MPa | Joint stress |
| bjoint | m | Joint width |
| FRd | kN/m | Joint capacity |
| Asfa | mm2/m | Actual shear reinforcement area in joint |
| Asfd | mm2/m | Required shear reinforcement area in joint |
Example of result-table (Topping joint):
Torsion, transverse capacity
When a torsion moment is present the following tables are shown for non-hollowcore elements. Torsional capacity for hollowcores are shown in the shear table.
| Symbol | Unit | Description |
|---|---|---|
| TEd | kNm | Torsion design moment |
| VEd | ||
| V'T | ||
| VRd,s | ||
| V'T/VRd,s | ||
| VRd,max | ||
| (Asw / s)cur | mm2/m | Applied (current) stirrup reinforcement area |
| (Asw / s)req | mm2/m | Required stirrup reinforcement area |
| (Asw / s)req min | mm2/m | Minimum stirrup reinforcement area |
| Ak |
Example of result-table (Torsion):
Torsion, longitudinal capacity
| Symbol | Unit | Description |
|---|---|---|
| TEd | kNm | Torsion design moment |
| TRd,l | kNm | Torsion capacity (longitudinal) |
| TEd /TRd,l | - | Utilization with regard to (longitudinal) torsion capacity |
| Asl,cur | mm2 | |
| Asl,req | mm2 | |
| uk | m | |
| Ak | m2 |
Example of result-table (Torsion):
Punching
For hollowcores a Punching table presented, if there are point loads defined.
| Symbol | Unit | Description |
|---|---|---|
| Base LC | - | Name of base load case in which the point is added |
| x | m | Position of the point load along the hollwocore |
| e | m | Eccentricity |
| b | mm | |
| Fd | kN | Design load |
| beff | m | Effective width |
| h | m | height |
| σcp | MPa | Compressive stress at the centroidal axis |
| Vrd | kN | Punching capacity |
| Fd / Vrd | - |
Example of result-table (Punching):
Flange reinforcement
For flanges beams with excentric loads placed on the flange, the required 'hanging reinforcement' is calculated and presented in the 'Flange Reinforcement' table.
| Symbol | Unit | Description |
|---|---|---|
| Load ID | - | index of the considered loads in this load combination |
| Load | kN, kNm | Magnitude of the design load |
| Span | m | Distribution length of the calculated reinforcement |
| As | mm2/m | Required amount of reinforcement |
| Util | - | Utilization |
Spalling (Hollowcore)
The spalling calculation is only being performed for the first serviceability limit state in a dependency-chain for hollowcores elements. The spalling table shows the spalling for each web. Calculation is being performed according to EN 1168 4.3.3.2.1 a)
| Symbol | Unit | Description |
|---|---|---|
| web | Shows the spalling calculation for each web. Web number from left (1, top of the table) to right (n, bottom of the table). n = number of webs. | |
| P0 | kN | Initial prestressing force just after release in the considered web or the total prestressing force in case of solid slabs |
| bw | mm | Thickness of the individual web or the total width b of the slab in case of a solid slab |
| hw | mm | Height of the web |
| eo | mm | Eccentricity of the prestressing steel |
| αe | - | (eo - k) / hw |
| lpt1 | mm | Lower design value of the transmission length |
| σsp | MPa | Spalling stress |
| fct | MPa | Tension strength of the concrete |
| Utilization | Utilization rounded to two decimals | |
| Comment | OK or Not OK!, depending on if the utilization is above or below 100% |
Example of result-table (Spalling, Hollowcore):
Fire results
Fire-related design results can be found here: Fire results.