In order to create a design, we must first have concluded an analysis.

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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.

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Utilization Table lets the user view the Utilization Ratios of the load combinations.

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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:

SymbolUnitDescription
MdkNmMoment
NikNPrestressing force
MikNmMoment due to prestressing force
σc,topMPaConcrete stress top
σc,btmMPaConcrete stress bottom
Crack stadium-I (uncracked), II (cracked)
σs,topMPaReinforcement stress top
σs,btmMPaReinforcement stress bottom
McrkNmMoment at point of cracking
wkmmCrack Width
zmmDeflection

Example of result-table (Bending, SLS):

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Bending, ULS

ULS elements use the following symbols:

SymbolUnitDescription
NdkNNormal force
MdkNmMoment due to loads
MukNmBending moment capacity
Md / Mu-Utilization
zmmInternal lever
xmmCompression zone height
εcConcrete strain
εsSteel strain
σs,topMPaReinforcement stress top
σs,btmMPaReinforcement stress bottom
σscMPaStress in the most compressed (or least tensile) reinforcement bare/wire
σstMPaStress in the most tensile (or least compressed) reinforcement bare/wire

Example of result-table (Bending, ULS) for hollowcore elements:

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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.

SymbolUnitDescription
VdkNShear design force
TdkNmTorsion design moment (conditional)
VRdkNFinal shear design capacity
Vd / VRd-Utilization with regard to concrete shear capacity
VRd,maxkNMaximum shear capacity
VcwkNCapacity due to web shear failure
VcbkNCapacity due to bend shear failure
VpkNShear capacity increase/decrease due to normal force
VikNShear capacity increase due to variable section depth
VcfckNShear capacity of core fillings (conditional, hollowcore only)
VEtdkNShear capacity decrease due to torsion (conditional, hollowcore only)
bwmmWeb width at neutral layer (accumulated)
dmmEffective depth

Example of result-table (Shear, ULS, without stirrups):

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Shear, with stirrups

Shear values for stirrups have different notation:

SymbolUnitDescription
VSdkNShear design force for stirrups
V'kNShear field force, used for design of stirrups
VRd,skNShear design capacity for stirrups
V' / VRd,s-Shear utilization for stirrups
VRd,maxkNMaximum shear capacity
(Asw / s)curmm2/mApplied (current) stirrup reinforcement area
(Asw / s)reqmm2/mRequired stirrup reinforcement area
(Asw / s)req minmm2/mMinimum stirrup reinforcement area
bwmmWeb width
zmmInternal lever

Example of result-table (Shear, ULS, without stirrups):

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Crack width

Crack width results are only available for SLS

SymbolUnitDescription
Crack stadium-I (uncracked), II (cracked)
Am2Effective area of cross-section
Im4Effective moment of inertia
ζ-Ratio between cracked and uncracked cross-section
McrkNmMoment at point of cracking
As,minmm2Minimum longitudinal reinforcement area required
As,currmm2Current longitudinal reinforcement area
sr,maxmmMaximum distance between cracks
wkmmCrack width

Example of result-table (Crack width):

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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.

SymbolUnitDescription
VdkNShear design force
FjointkN/mJoint force
ffMPaJoint stress
bjointmJoint width
FRdkN/mJoint capacity
Asfamm2/mActual shear reinforcement area in joint
Asfdmm2/mRequired shear reinforcement area in joint

Example of result-table (Topping joint):

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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.

SymbolUnitDescription
TEdkNmTorsion design moment
VEd  
V'T  
VRd,s  
V'T/VRd,s  
VRd,max  
(Asw / s)curmm2/mApplied (current) stirrup reinforcement area
(Asw / s)reqmm2/mRequired stirrup reinforcement area
(Asw / s)req minmm2/mMinimum stirrup reinforcement area
Ak  

Example of result-table (Torsion):

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Torsion, longitudinal capacity

SymbolUnitDescription
TEdkNmTorsion design moment
TRd,lkNmTorsion capacity (longitudinal)
TEd /TRd,l-Utilization with regard to (longitudinal) torsion capacity
Asl,curmm2 
Asl,reqmm2 
ukm 
Akm2 

Example of result-table (Torsion):

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Punching

For hollowcores a Punching table presented, if there are point loads defined.

SymbolUnitDescription
Base LC-Name of base load case in which the point is added
xmPosition of the point load along the hollwocore
emEccentricity
bmm 
FdkNDesign load
beffmEffective width
hmheight
σcpMPaCompressive stress at the centroidal axis
VrdkNPunching capacity
Fd / Vrd- 

Example of result-table (Punching):

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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.

SymbolUnitDescription
Load ID-index of the considered loads in this load combination
LoadkN, kNmMagnitude of the design load
SpanmDistribution length of the calculated reinforcement
Asmm2/mRequired amount of reinforcement
Util-Utilization

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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)

SymbolUnitDescription
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.
P0kNInitial prestressing force just after release in the considered web or the total prestressing force in case of solid slabs
bwmmThickness of the individual web or the total width b of the slab in case of a solid slab
hwmmHeight of the web
eommEccentricity of the prestressing steel
αe-(eo - k) / hw
lpt1mmLower design value of the transmission length
σspMPaSpalling stress
fctMPaTension 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):

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Fire results

Fire-related design results can be found here: Fire results.

 

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PRE-Stress Documentation