If the wind load for buildings or structures is to be determined by the simultaneous assumption of aerodynamic pressure and suction coefficients on the windward and leeward sides of the building, the correlation of the wind pressure on zones D and E of the wall surfaces may be taken into account.
If nodal supports should have an effect in certain directions only, you can define failure. Here is an example of a single‑span beam, of which the right support can only absorb positive vertical loads. The load comprise vertical suction load and horizontal load. However, there are 2 failure options: 1) Failure if negative PZ' 2) Failure all if negative PZ' The difference is illustrated in the graphic.