Vibration Mode Shapes



Check the vibration mode shapes and natural periods of a model.




From the Main Menu select Results > Mode Shape > Mode Shapes > Vibration Mode Shapes.



Load Cases (Mode Numbers)

Select the desired mode numbers.

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


Select a desired mode component among the following:

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

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

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





Type of Display

Assign the type of display as follows :


Display the vibration mode shapes.


Control the Scale Factor for vibration mode shapes.

Mode Shape Scale Factor

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.



Display additionally the model shape in the buckling mode shapes.
The representation of the model shape can be controlled in Display Option.


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

: Express as exponentials

Min & Max: Display the maximum and minimum values

Abs Max
: Display the absolute maximum value

: Display only the maximum value

: Display only the minimum value

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

Set Orientation: Display orientation of numerical values

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

Set Orientation = 0 horizontally displays the numerical values to the right of nodes or elements.

The orientation angle represents the counter-clockwise direction, which may be used to enhance the readability of the numbers.


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



Dynamically simulate the vibration modes.
Click 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

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

: 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



Display the vibration modes in contour.


Ranges: Define the contour 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)

Colors: Assign or control the colors of the contour.

Color Table: Assign the type of Colors.

: 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

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: Display the boundaries of the contour in a mono color.

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

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).


Revision of Civil 2014 (v2.1)

Q1. I am trying to model a 3span post tensioned girder bridge. When I perform the Eigenvalue analysis with ends of the piles pinned, I get 93% mass participation in X & Y direction. But, when I assign point springs supports to represent soil structure interaction, the mass participation drastically reduces to 60%. I expect at least 90% mass participation within 10 modes. Please explain.