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Mode Shape Created Edited

Buckling Mode Shapes


  • Check the Buckling Mode Shapes and Critical Buckling Load Factors of a model.



From the main menu, select [Results] tab > [Type : Analysis result] > [Mode Shape] group > [Mode Shapes] > [Buckling Mode Shapes]



Results-mode shape-buckling mode shape.png

Buckling Mode Shapes dialog box


Load Cases(Mode Numbers)

Select the desired mode numbers.

Press Multi-Modes and select a desired option to simultaneously verify several mode shapes.



Select a desired mode component among the following:

Md-X : Buckling mode component in GCS X-direction

Md-Y : Buckling mode component in GCS Y-direction

Md-Z : Buckling mode component in GCS Z-direction

Md-XY :

Md-YZ :

Md-XZ :

Md-XYZ :


Type of Display

Assign the type of display as follows:


1. Md.Shp.

Display the buckling mode shapes.


Mode Shape Scale Factor : Control the Scale Factor for buckling mode shapes.

Cubic Interpolation : Display the elements by cubically interpolating the mode shapes (including rotation angle) of each node.

Cubic Interpolation Factor : Factor to be applied for cubic interpolation. It affects the curvature of elements.


2. Undeformed

Display additionally the model shape in the buckling mode shapes.

The representation of the model shape can be controlled in Display Option.


3. Values

Display the component of a buckling mode in numerical values.

The font and color of the numbers can be controlled in Display Option.


Decimal Points : Assign decimal points for the displayed numbers

Exp. : Express as exponentials

Min & Max : Display the maximum and minimum values

Abs Max : Display the absolute maximum value

Max : Display only the maximum value

Min : Display only the minimum value

Limit Scale(%) : Set the screen display limit for buckling mode shapes relative to the selected maximum or minimum value

Set Orientation : Display orientation of numerical values

NOTE.png The default Decimal Points can be controlled in "Preferences".


4. Legend

Display various references related to analysis results to the right or left of the working window.


Legend Position : Position of the legend in the display window.

Rank Value Type : Specifies the output format and decimal places for the legend values.


5. Animate

Dynamically simulate the buckling modes.

Click Apply then click Record to the right of the Animation control board at the bottom of the working window.


Animation Mode : Select the type of animation for analysis results.

Animate Contour : Option to change the color of the contour representing the transition according to the magnitudes of variation.

Repeat Half/Full Cycle : Select the repetition cycle for the dynamic representation of the transition.

NOTE.png Select 'Half Cycle' for the transient shapes of a structure and 'Full Cycle' for dynamically simulating vibration modes or buckling modes.

AVI Options : Enter the options required to produce the animation window.

Bits per Pixel : Number of bits per pixel to create the default window for animation.
Compressor... : Assign the method of the compressing image data.

Frames per Half Cycle(3~300) : Number of frames to simulate a 'Half Cycle'.

Frames per Second(5~60) : Number of frames per second to present dynamic simulation.

Construction Stage Option : Specifies the animation method when performing analysis for each construction stage.

Stage Animation : Animation based on construction stages.

Current Stage-Step : Animation by step in the current construction stage.

From ~ To : Select the starting and ending construction stage or step for the animation.


6. Contour

Display the buckling modes in contour.


Ranges : Define the contour range.

Customize Range... : Assign the color distribution range of contour. Using the function, specific colors for specific ranges can be assigned.
Number of Colors : Assign the number of colors to be included in the contour (select among 6, 12, 18, 24 colors)

NOTE.png The ability to specify Contour Range Max/Min values outside the range of the output values has been added. If the values are within the Min/Max range, they will be treated as before. However, if they exceed the range, the Min/Max values will be entered at Rank 0 and Rank 11.

Colors : Assign or control the colors of the contour.

Color Table : Assign the type of Colors.

Customize Color Table... : Control the colors by zones in the contour.

Reverse Contour : Check on to reverse the sequence of color variation in the contour.

Contour Line : Assign the boundary line color of the contour.

Element Edge : Assign the color of element edges while displaying the contour.

Contour Options : Specify options for contour representation.

Contour Fill

Gradient Fill : Display color gradient (shading) in the contour.

Draw Contour Lines : Display color boundaries in the contour.

Draw Contour Line Only

Display only the colored boundaries of the contour.

Mono line : Represents the boundaries of contour lines in a monochromatic color scheme.

Contour Annotation

Legend or annotation signifying the ranges of the contour is displayed.

Spacing : Display the spacing for the legend or annotation.

Coarse Contour(faster) (for large plate or solid model)

Represent a simplified contour for a large model using plate or solid elements in order to reduce the time required to represent a complete contour.


Where plate elements or solid elements along a cutting plane are represented in contour, a three dimensional contour is created. The positive direction of the analysis results is oriented in the z-axis direction of the local element coordinate system.
The option is not concurrently applicable with the Deformed Shape option. Similarly, the option can not be concurrently applied to the cases where Hidden option is used to display plate element thicknesses or Both option is used to represent Top & Bottom member forces (stresses).


Update Model with Imperfections

Create a new model file in which the geometry of analysis model is updated based on the mode shape of linear buckling analysis. The new model can be used for geometric and material nonlinear analysis to find a buckling load.


Update Model with imperfections

Buckling Mode : Selects the mode shape to be applied when updating the nodal coordinates of the analysis model.

Scaling : The mode shape is modified in size by the Scale Factor or Maximum Mode Shape. The updated mode shape is then applied to the nodal coordinates.

Scale Factor

Updated coordinate = (initial coordinate) + (mode shape) x (scale factor)

Maximum Value

Updated coordinate = (initial coordinate) + (mode shape) x (maximum value)/(maximum mode shape)

NOTE.png When 'Maximum Value' is selected, the mode shape values are adjusted based on the DtXYZ(V) values. 
- Buckling mode shape of a node. (Relative displacement of buckling mode shape) DtX(V)=1, DtY(V)=2, DtZ(V)=3, DtXYZ(V))=3.742
- Maximum Value = 5
- Scaling DtX(V)=1x(5/3.742), DtY(V)=2x(5/3.742), DtZ(V)=3x(5/3.742), DtXYZ(V))=3.742x(5/3.742)

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