1D stresses

The 1D internal forces command serves for displaying internal forces on selected 1D members. (not only on Beams, but also on Ribs, Tendons and Integration strips/members)

Usage

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

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

Properties

Category	Property	Description / Notes
Selections	Type of selection All / Current / Advanced / Named Selection	Specifies on what members the results are displayed See "Type of selection"
Selections	Filter No / Cross-section / Material / WildCard / Layer / Type of beam
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 1D	Extreme 1D No / Section / local / Cross-section / Design group / Member / Global	Defines the position where extremes of result value are evaluated. note for "extreme no" option: If selected combination or class consist of too many linear combinations and thus it is not possible to display the results in full - conservative method that only displays results for linear combinations causing an extreme response of the structure is used instead.
	Type of values Basic magnitudes / Principal magnitudes
	Values	See table Values below.
	Interval On / Off	Activation of interval of values for displaying in 3D window and in result tables.
	Minimum [ ]	It is available only if Interval functionality is ON. User can define minimal value of interval. This item is unique for every type of unit used in Values.
	Maximum [ ]	It is available only if Interval functionality is ON. User can define maximal value of interval. This item is unique for every type of unit used in Values.
	Fibres All / Top / Bottom / Named fibre / All named fibres
	Cross-section parts All / Named cross-section part
	Consider torsion due to shear centre eccentricity On / Off	With this option ON, the shear forces are considered to act in the centre of gravity and therefore the shear stresses are magnified by additional torsion effect from eccentricity of shear forces. Shear stresses on 1D members are calculated by default from shear forces and torsion moment, where shear forces are considered to act in the shear centre of the beam's cross-section. In case of cross-section with different position of shear centre with respect to the centroid of gravity this approach leads to discrepancy in the position of acting forces. Typical example of such cross-section is hot-rolled U shaped cross-section.
	Print combination key On / Off
	Results in sections All / Selected	If results in sections is set on Selected, new possibilities are available Ends / Close to middle / Inputted
Output settings	Print combination key On / Off
Output settings	Display info about used interval On / Off	It is possible to display or not display in header of result tables information about applied intervals.
Drawing Setup 1D		" Drawing setup 1D"
Errors, warnings and notes settings		"Errors, warnings and notes settings"

Values

The following categories of 1D stresses can be displayed:

Basic magnitudes

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

Value	Description	Notes
σ_x	normal 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.
t_xy/t_xs	transverse shear stress from Vy	They are calculated from the shear force and torsional moment using unit distribution of shear stresses. Those unit distributions of shear stresses are also available in the cross section editing dialogue. The t_xs magnitude represents: walled cross section. Distribution of this shear flow from horizontal a vertical unit shear forces can be checked in the cross section manager.
t_xz/t_xs	transverse shear stress from Vz
t_tor/t_xs	torsional shear stress from Mx
Components	possibility to choose more than one value and display them together in 3D window. Only selected values will be displayed in result tables.

Principal magnitudes

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	maximum principal stress
σ₂	minimum principal stress
σ_E	equivalent stress (von Mises)
t_tot	total shear stress
Components	possibility to choose more than one value and display them together in 3D window. Only selected values will be displayed in result tables.