Urgent: Full-penetration double sided groove weld sizin

I need help. I have an IPE400 lifting beam and i have to make it longer by welding an another IPE400 to it with full penetration double sided groove welds. I want to check it in Solidworks Simulation Edge Weld Connectors. When i make the edge weld connector for double sided groove weld what data should i give for estimated weld size for full penetration double sided groove weld?

The web thickness for IPE400 is 8,6 mm. 

Questions:

  • For a single sided full penetration groove weld the estimated weld size should be 8,6 mm? (the one on the left)
  • For a double sided full penetration groove weld the estimated weld size should be 8,6/2=4,3 mm? (the one on the right)

    SOLIDWORKSSimulation 

Ofc, for the flanges i will make a separate edge weld connector, with another sizing.
Thank you in advance for your answer!