# Global Surface Load \[FEA]

Global surface loads apply distributed pressure over a polygonal area defined by a set of points. The load is distributed to nodes within the specified FE group that fall within the defined area. This is useful for applying area loads such as deck overlays, snow loads, or equipment pads without referencing individual elements.

## Surface Load

**Load Case:** The analysis case (load case) to which this surface load belongs.

**Group:** The FE group containing the elements to which the load will be distributed. The load is applied to nodes of the elements within this group that fall within the defined polygon.

**Points:** Defines the polygon area over which the surface load is applied. Points are defined as X, Y, Z coordinates. Right-click this cell for actions: *Edit Points...* opens a point editor for manual coordinate entry; *Select Polygon (3D)...* launches an interactive 3D picker that lets you click on surface element corners to define the polygon directly in the model view.

**Fx:** Distributed pressure in the global X direction (force per unit area).

**Fy:** Distributed pressure in the global Y direction (force per unit area).

**Fz:** Distributed pressure in the global Z direction (force per unit area). Use negative values for downward pressure loads.

**Convert to Node Load:** When set to Yes, the load is converted to equivalent nodal forces before analysis. This can improve performance for large models.

## Load Distribution

**Load Type:** Controls how the load is distributed across the surface area. Select "Uniform" for a constant pressure across the entire area, or "Linear" for a linearly varying load defined by the direction vector and coefficients.

**Direction X:** The X component of the direction vector along which the load varies linearly. Only used when Load Type is set to "Linear".

**Direction Y:** The Y component of the direction vector along which the load varies linearly. Only used when Load Type is set to "Linear".

**Direction Z:** The Z component of the direction vector along which the load varies linearly. Only used when Load Type is set to "Linear".

**Load Coeff 1 (Base):** The load coefficient at the base (start) of the linear variation. The actual load at any point is interpolated between Coeff 1 and Coeff 2 based on the point's projection along the direction vector. Default is 1.

**Load Coeff 2 (Apex):** The load coefficient at the apex (end) of the linear variation. Default is 0, which means the load decreases linearly to zero along the specified direction.