Beams resist the global moment by a force couple, with lever arm of 2/3 the beam depth d; resisted by top compression C and bottom tension T.
Trusses resist the global moment by a force couple and truss depth d as lever arm; with compression C in top chord and tension T in bottom chord. Global shear is resisted by vertical and / or diagonal web bars. Maximum moment at mid-span causes maximum chord forces. Maximum support shear causes maximum web bar forces.
Suspension cables resist the global moment by horizontal reaction with sag f as lever arm. The horizontal reaction H, vertical reaction R, and maximum cable tension T form an equilibrium vector triangle; hence the maximum cable tension is:
Arches resist the global moment like a cable, but in compression instead of tension: