Displaying the internal forces on slabs (PPEv17)

The procedure to display the internal forces

  1. Open service Results.

  2. Select function 2D members > 2D Internal forces.

  3. Set result properties

  4. Refresh

Parameters for 2D results

Description for basic settings of 2D results can be found here: Selection and filter ; Loading

Special settings for 2D results are:

Averaging of peak

To activate the averaging algorithm

 Displaying the averaged results, Averaging strips
Rib Turns ON/OFF rib effect on slab Calculation of internal forces in ribs

Location

Sets how the results will be displayed related to mesh

 Averaging of results in FE nodes

Type of values

2D internal forces provides three types of values - basic, principal, elementary design

 Calculated results for 2D members

Standard result

 Shows results on slab plane, drawing is handled by 2D drawing setup 2D drawing setup
Result on section Shows results on sections, drawing is handled by 1D drawing setup (same as for any other 1D member) 1D drawing setup
Result on edges Shows results on slab edges, drawing is handled by 1D drawing setup (same as for any other 1D member) 1D drawing setup

Type of forces

As mentioned above, there are three different types of force. The following tables summarise individual options.

Basic magnitude

Project: plate

mx

bending moment of 2D member in x direction

my

bending moment of 2D member in y direction

mxy

torsion moment of 2D member  

vx

shear force perpendicular to plane of 2D member in x direction

vy

shear force perpendicular to plane of 2D member in y direction

Project: wall

nx

normal force of 2D member in x direction

 ny

normal force of 2D member in y direction

 nxy

membrane shear force of 2D member  

Project: general (shell)

mx

bending moment of 2D member in x direction

my

bending moment of 2D member in y direction

mxy

torsion moment of 2D member  

vx

shear force perpendicular to plane of 2D member in x direction

vy

shear force perpendicular to plane of 2D member in y direction

nx

normal force of 2D member in x direction

ny

normal force of 2D member in y direction

nxy

membrane shear force of 2D member  

Principal magnitude

Note: Lower index "m" at the quantity name means the membrane component. Lower index "b" at the quantity name means the bending component.

Project: plate

m1, m2

principal moments

alfa

angle between the direction of m1 and planar axis xP

mtmax

maximal torque moment

qmax

maximal shear force

Project: wall

n1, n2

principal axial forces

alfa

angle between the direction of n1 and planar axis xP

Project: general (shell)

m1, m2

principal moment

alfab

angle between the direction of m1 and planar axis xP

qmax-b

maximal shear force from bending effects

beta

angle between the direction of qmxo and planar axis xP

n1, n2

principal axial forces

alfam

angle between the direction of n1 and planar axis xP

qmax-m

maximal shear force from membrane effects

Design magnitude

Project: plate

mxD+, myD+, mcD+, mxD–, myD–, mcD–

Project: wall

nxD, nyD, ncD

Project: general (shell)

mxD+, myD+, mcD+, mxD–, myD–, mcD–, nxD, nyD, ncD

Only relevant design moments are drawn per surface. For upper top surface we show only negative values, and for bottom we show only positive values.

Note: Starting with version 18.0, when viewing design moments for the top surface, if the type of load is set to 'Class', setting the envelop to 'Minimum' will display the highest negative values resulting from the combinations in the class and setting the envelop to 'Maximum' will display the lowest negative values. This differs from the methodology in 17.9 and prior, where all values were shown as positive and setting the envelop to 'Maximum' displayed the highest values.

In case of result on section we also respecting general rule of drawing the negative bending moment up (as it is relevant for upper surface) and positive moment down (as it is relevant only for bottom surface)

 

Design forces in a wall are in the middle plane.

Corresponding surface of action of design moments in shells is given directly by the sigh of the moment.

See also chapters Principal internal forces and Design internal forces.

See also chapter Style of isolines.