Quote (75 meter aluminium dome roof. We are doing the ground assembly using Chain pulley blocks hanged in Tripods. As we move further to the periphery we find that, while lifting the structure using tripods the struts (beams) getting bent and even cracked at few locations.)

Apparently the picture depicts web buckling of the alu. profile and experienced high load due to lifting operation. Probably , the pulleys did not operate simultaneously in sequence .. The no. of Chain pulley tripods and locations should be studied by an experienced engineer and lifting shall be simultaneously ( without lifting one of the point to final position).

When you write ( vacono dome lifting ) and search the web , one of the outcomes,

https://www.youtube.com/watch?v=3oqzJC2Wz-k

Well as the roof gets larger the weight increases and that connecting plate is simly not strong enough to withstand the forces imposed by that strap which is creating forces which the connecting plate cannot resist.

What does the construction plan say?

Why are you not lifting from the top of the connecting plates? why not have a beam under the flat connecting plates and lift on both sides?

This seems to indicate a poor appreciation of construction loads from the strap and you need to find a way to create only vertical lift forces and not the crushing loads that the strap is providing.

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Wouldn't the manufacturer's prints show the lifting points of this frame work?