Variables: delta, P, I, k, k.sum, P.actua

Constants (known): h, E,

Equations: delta=P*h^3/(3*E*I), k=1/delt

There is a delta, P, & k for 5 different members (in my case, shearwalls). "I" & "h" are known, but may be different for each member, so there may be a different delta & k result for each member

Member1 delta1=P1*h1^3/(3*E*I1), k1=1/delta
Member2 delta2=P2*h2^3/(3*E*I2), k2=1/delta
Member3 delta3=P3*h3^3/(3*E*I3), k3=1/delta
Member4 delta4=P4*h4^3/(3*E*I4), k4=1/delta
Member5 delta5=P5*h5^3/(3*E*I5), k5=1/delta

k.sum=k1+k2+k3+k4+k

I initially set P=100 to find k. Then k is used in a series of cells/formulas to determine a calculated P (the equations are too complex/lengthy to list here). Let's just say for simplicity's sake that P1.actual=V*k1/k.sum. I then want to use P1.actual in place of P1 to determine a new delta1 & k1. From that a new P1.actual is calculated, which in turn is used to find a new delta1 & k1. I want this iteration to continue until convergence so I can find an unknown, but exact P.actual, delta, & k for each member. Hope this is descriptive enough. Feel free to email me @ if you need to

Brad