The figure shows the free body diagram around flange B. The free body diagram cuts through members 1 and 2. The load on the flange is P which equals 110 kilo newtons directed vertically downwards. The reaction force on member 1 is F subscript 1 directed vertically upwards. The reaction force on member 2 is F subscript 2 directed vertically downwards. The parameters corresponding to member 1 are A subscript 1, L subscript 1 and E subscript 1 and the parameters for member 2 are A subscript 2, L subscript 2 and E subscript 2.

Solve for F1:

F1-F2-P=0

F1=F2+P

and substitute the expression for F1 into the compatibility equation:

(F2+P)L1A1E1+F2L2A2E2=0

Solve this equation for F2:

F2 L1A1E1+L2A2E2=-PL1A1E1

F2 =-PL1A1E1L1A1E1+L2A2E2