PreVABS v1.2 Release

  1. Haodong Du

    Hello, PreVABS v1.2 is released. PreVABS is the preprocessor of VABS to facilitate design of Composite blades and airfoils. PreVABS v1.2 introduces some new features like sublayups and segment parametrization. Comments and suggestions of new features are welcomed.

    Download link:

    Windows x64:




    Example 1: Sublayup capability

      <layup name="...">
        <layer lamina="lamina_name">angle:stack</layer>
        <layer lamina="lamina_name">angle:stack</layer>
        <layer lamina="lamina_name">angle:stack</layer>
        <layer layup="sublayup_name"/>

    Using sublayup to construct a layup facilitate the layup constructions when different layups share some common layers. A sublayup is built like an actual layup, but it must appear before the layup where it is referenced.

    Example 2: Use parametrized points to construct segments

    <component name="...">
        <layup begin="0.1">layup_2_name</layup>
        <layup end="0.7">layup_3_name</layup>
        <layup begin="0.2" end="0.9">layup_4_name</layup>

    Now you can parametrize the points on an airfoil and optimize it.

    Release Notes

    What's New?


    • Added a new capability to create layups from sublayups.
    • Added a new capability to create segments using normalized parametric locations on a base line.


    • Added a new format for the input file. Now baselines and layups data are merged into the main input file, to reduce the number of input files needed.
    • Added a new material type 'lamina' accepting four elastic properties (e1, e2, g12, nu12). 
    • Added default small numbers for elastic properties for isotropic materials. 
    • Added the fill-type component for non-structural mass. 


    • Added capability to create quadratic triangle elements. In the main input file, under the xml element , create a sub element  and set it to quadratic or 2. Default is linear.
    • Added a new output file *.txt storing all running messages.

    Fixes and changes


    • Fixed the problem of unable to read recover analysis result files on Linux.
    • Fixed a problem when the segment is too short while the laminate is too thick.


    • Changed one of the layup methods tag name from 'explict list' ('el') to 'layer list' ('ll').
    • Fixed the crashing issue caused by zero number of layers.
    • Fixed the bug that sectional loads were read and written to the distributed loads when doing recovery using VABS.
    • Fixed the bug that local lamina data does not overwrite global data.