2D stress / strain

The 2D stress / strain command serves for displaying stresses and strains on selected 2D members.

Usage

  1. Calculate a FEM analysis of the model
  2. Go to Tree > Results > 2D members > 2D stress / strain
  3. Set properties of the command to specify mainly:
    • selection of 2D members where the results are evaluated
    • load type from which the results are derived
    • specific result value from the available list to be visualized
  4. Click on [Refresh] action button to display the results

Note: To get general overview about how to work with a Result service and its commands, see Results/Basics.

Properties

Category Property Description / Notes
Selection

Type of selection
All / Current / Advanced / Named Selection

Specifies on what members the results are displayed
See "Type of selection"

 
Filter

No / Material / WildCard / Layer / Thickness
Result case

Type of load
Load case / Combinations / Classes / Nonlinear Combinations/ Stability Combinations / Mass combinations

 Defines for what load the results are displayed.
See "Result case"
Extreme

Averaging of peak
On/Off

Activates averaging of peaks of results in places where averaging strips are applied.
See Results/Tools/Averaging strip
See Results/Theory/Averaging_peaks

Rib
On/Off

 

 Controls whether the components of internal forces parallel with the direction of the rib are neglect in area of effective width (the forces are recalculated to 1D results of the rib instead).
See Results/Theory/Rib_option
Location
In centres / In nodes no avg. / In nodes avg. / In nodes avg. on macro

Determines way how results - calculated in the nodes of individual finite elements - are further processed (averaged) to get smoother continuous distribution.
See Results/Theory/Smoothing_results

System
LCS mesh element / LCS - Member 2D

 Sets a coordination system which is used as referenced for displaying the results.
See Results/Theory/Local_axes_2d

Extreme

Mesh / Member / Global

 Defines for which extreme on 2D member the results are displayed.
Type of values

Basic stress / Principal stress / Membrane stress / Basic total strain / Principal total strain / Principal plastic strain

  
Value See table Values below.
Standard result
On/Off		 Display standard results on 2D members.
Results on sections
On/Off		 Display results on defined sections on 2D members.
Results on edges
On/Off		 Display results on the edges of selected 2D members.
Output settings Print combination key
On/Off		  
Table setup   Possibility to define columns with values in preview window.
Drawing Setup 2D   "Drawing setup 2D"
Errors, warnings and notes settings   "Errors, warnings and notes settings"

Values

The following categories of stresses and strains can be displayed:

Note: As default, the stresses and strains refer to the local axes of the individual finite (mesh) elements. The local axes can be displayed by selecting the corresponding option in the View parameters settings.

Basic stress

The basic stresses are default magnitudes referring to the local axes of the selected coordination system.

Value Description Notes
σx+

stress in direction of local axis x


 It is calculated on assumption of linear distribution of the strain within the section. In the first step the plane of deformation is calculated using iterative algorithm () so strain in all fibres is known. In the next step adequate stresses are assigned using stress-strain curve. Remember that linear calculation uses linear approximation (E modulus) of stress-strain curve.
σy+

 

stress in direction of local axis y

  
σx-

stress in direction of local axis x

 
σy-

 

stress in direction of local axis y

  
txy+

shear stress

The shear stresses are evaluated differently for thick-walled and thin-walled cross section. For thick-walled (solid) sections the real txyor txzare calculated and displayed.

For thin-walled sections the final shear flow from unit forces in Y or Z directions are evaluated and displayed as total shear flow:

See also chapters in manual related to calculation of sectional characteristics.
txy-

shear stress
txz

shear stress perpendicular to the plane
tyz

shear stress perpendicular to the plane

Principal stress

The principal stresses represent the extreme values of the internal forces derived from the basic ones by transformation into the directions of principal axes:

Value Description Notes
σ1+

principal stress on positive face (max)

 

1) The angles of principal magnitudes are derived from to the local axis x.

2)The principal magnitudes can be visualized also as trajectories (see the option Trajectories in the command properties).
σ2+

principal stress on positive face (min)
a+

angle of principal stress σ1+
σE+

equivalent stress on positive face (von Mises)
σ1-

principal stress on negative face (max)

 
σ2-

principal stress on negative face (min)
a-

angle of principal stress σ1-
σE-

equivalent stress on negative face (von Mises)
tmax,b

Maximum shear stress perpendicular to the plane

 

Membrane stress

Value Description Notes
σm1

principal membrane stress on positive face (max)

  
σm2

principal membrane stress on positive face (min)
σmE

membrane equivalent stress (Mises)
am angle of principal membrane stress σm1

Basic total strain

The basic strains are default magnitudes referring to the local axes of the selected coordination system.

Value Description Notes
etot,x+

strain on positive surface
etot,y+

strain on positive surface
gtot,xy+

slope on positive surface
etot,x-

strain on negative surface


  
etot,y-

strain on negative surface
gtot,xy-

slope on negative surface

Principal total strain

The principal strains represent the extreme values of the internal forces derived from the basic ones by transformation into the directions of principal axes:

Value Description Notes
etot,1+

principal strain on positive surface (max)


  
etot,2+

principal strain on positive surface (min)
a+

angle of principal strain on positive surface
etot,1-

principal strain on negative surface (max)
etot,2-

principal strain on negative surface (min)
a-

angle of principal strain on negative surface
etot,M+

equivalent strain on positive surface (Mises)
etot,M-

equivalent strain on negative surface (Mises)

Basic plastic strain

The basic plastic strains are default magnitudes referring to the local axes of the selected coordination system. The basic plastic strains are part of basic total strains after nonlinear calculation with functionality "General plasticity" for elasto-plastic material.

Value Description
epl,x+

for elasto-plastic material without hardering

for elasto-plastic material with hardering

 
epl,y+
gpl,xy+
epl,x-
epl,y-
gpl,xy-

Principal plastic strain

The principal plastic strains represent the extreme values of the internal forces derived from the basic ones by transformation into the directions of principal axes. The principal plastic strains are part of principal total strains after nonlinear calculation with functionality "General plasticity" for elasto-plastic material.

Value Description
epl,1+

for elasto-plastic material without hardering

for elasto-plastic material with hardering
epl,2+
a+
epl,1-
epl,2-
a-
epl,M+
epl,M-