The formula for the full plastic nail arrangement modulus Zpxy which is used in the calculation of the ultimate shear capacity of the sheathed shear walls with any nail arrangement was theoretically derived by using the upper bound theorem.
The unknown values are the rotation ratio (θx/θy) and the neutral axis positions (xo and yo) in the calculation.
The difference between the calculation with the elastic values and the plastic values as unknown values is within 1.5%.
