Double weapons

[Sharkon]

The fighter of my party is level 11 nad plays with an orc-double axe. He has 5 attacks :3 from +11 base attack bonus and 2 more from two weapon fighting feats. How much of his STR modifier can he add to each attack? Should all 5 attacks do 1+1/2 * his str mod ? Or 3 of them be done with 1* str mod and the other 2 0.5 * str mod ?

 

[Alzrius]

Or 3 of them be done with 1* str mod and the other 2 0.5 * str mod ?

This. Those other two attacks from his TWF feats get 1/2 Str modifier to damage, while the primary three attacks get the full, unaltered Str modifier to damage.

 

[Bungus]

This. Those other two attacks from his TWF feats get 1/2 Str modifier to damage, while the primary three attacks get the full, unaltered Str modifier to damage.

This is correct - don't have anything else to add on, just wanted to affirm Alzrius.