Catia Static Analysis - Weld Connections?

[MBCatia]

Hello experts,

I made a part like below,

https://files.engineering.com/getfile.aspx?folder=1b182319-4b4f-465b-9908-6a4dbaa7262c&file=11.PNG

This part became with diffrent parts together and using welds.

But I made it just one part and not consider weld connections.

Is it true or Am I have to consider this welds? How effect yield stress these welds.

Your opinion please

Best regards.