Both flexural moment and shear strength is controlled automatically according to 7.5.1.1.
Dimensions of the cross-section should be satisfy ACI Eq. (22.5.1.2). It’s automatically controlled and users are warned if the rule is not satisfied.
Symbols
Mu = factored flexural moment at section, lb
Mn = nominal flexural strength at section, in.-lb
f'c = specified comprehensive strength of concrete, psi
Ac-sh = area of concrete used to determine shear stress, in2
Ag = gross area of concrete section, in2
bw = web width or diameter of circular section, in.
d = distance from extreme compression fiber to centroid of longitudinal tension reinforcement, in.
h = overall thickness, height, or depth of member, in.
s = center-to-center spacing transverse reinforcement, in
Vc = nominal shear strength provided by concrete, lb
Vn = nominal shear strength, lb
Vs = nominal shear strength provided by shear reinforcement, lb
Vu = factored shear force at section, lb
To design diaphragms for each applicable factored load combination, it’s controlled automatically whether it’s satisfied ΦSn ≥ U. Interaction between load effects are considered. Φ is automatically designed according to Strength Reduction Factors.
ΦMn ≥ Mu
ΦVn ≥ Vu
Design strengths of diaphragms idealized with finite-element model are determined in accordance with Chapter 22. Detailed information: Sectional Strength. Nonuniform shear distributions is considered in design for shear.
7.5.2 Moment
Mn is determined according to 22.3 as nominal flexural strength Mn is calculated as shown below. Detailed information: Flexural Strength
7.5.3 Shear
Vn is determined according to 22.5. Nominal one-way shear strength at a section, Vn, is calculated by eq. 22.5.1.1.
The shear strength is based on an average shear stress over the effective cross section, bwd. Therefore dimensions of the cross-section should be satisfy ACI Eq. (22.5.1.2). Detailed information: One-Way Shear Strength
