Stewart Platform: how can i connect multiple joints to the same child link but different parent links ?!

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I want to simulate and control the famous stewart platform in ROS and gazebo. I started with modeling the system in Solidworks and when i wanted to export the assembly to a URDF description i ran into a problem that the URDF description doesn't allow multiple joints to have the same child with different parents. Thus when i try to connect the different arms to the platform i end up with an error stating that there are multiple links with the same name. My question is: Is there any work around for this? I have searched for the problem and i found that SDF description supports closed loop joints, is this a solution to my problem ?! Here's link to a picture of my model in Solidworks to help you visualize the system:

Stewart Platform

Thanks in Advance