10.10 determination of redundant member forces for truss structures 了，bar forces (Fabl R1产 R21 (c) R31 △10+△1R=0 △1R=/1X S=So+SX1 同 9 Example 110= ΣR风 ∑ 53.3 。=0 Fo (kN) 75.4 378 3m.8 6.7 26.7 20.7 1R=80 R0=53.3 R0=287 707 a小1=X=1 (kN) 707 0 R1=0 R21=0 R31=0