SOFTEAM released the SysML Designer module as an open source extension for the Modelio 1.2. You may find below the download information. The prototype is compatible with Modelio FREE 1.2, however it is recommended to try it with Modelio Enterprise Edition.

The SysML Designer implements the OMG SysML 1.2 standard

1. Download and install Modelio Enterprise Edition v. 1.2
   
2. Download, unzip and deploy SysML Designer module from the SourceForge.
3. Check the User's Guide for more information. A nice example is added in the distribution package.
   

Note: The SysML requirements modeling is done with RequirementsAnalyst module that is available with Modelio Enterprise Edition only.