API 4F Wind Loading - ANSYS ACT Extension
Wind loads are common load cases in many outdoor structures spanning multiple industries (ex: derrick and mast designs). In the past, applying wind loading in FEA would have been a cumbersome and complex task. Currently, a free ANSYS ACT Extension is available in the ANSYS App store that simplifies this process greatly. The “API 4F Wind Loading v1” application applies wind loading to structures as per the API 4F Specification: “Specification for Drilling and Well Servicing Structures” (2008 edition). It is capable of handling geometries and meshes comprised of solid, shell, and beam elements in ANSYS Mechanical. ANSYS versions 17 and 18 are supported.
The methodology for solid and shell elements utilizes surface effect elements (surf154) to apply wind loads. This type of element overlays the surface and acts as a conduct for surface loads. For solid and shell elements, the extension has a pre-programmed assistant to detect the actual windward faces. This ensures that based on wind direction, the correct elements have wind applied.
For structures made of beam elements, no 3D element geometry exists on which to apply the wind forces directly. The ACT extension is even more useful in this case. Wind loads are applied to the actual faces, surfaces, and edges of the supported beam section type selected. Most beam section types are supported except User integrated and user defined beam shapes are not supported.
Some other highlights of this extension are that wind load can be applied to leeward side as well and multiple wind load cases are allowed. Gust effect, shielding and other factor inputs are also accepted.
The ANSYS 18 version can be found here: API 4F Wind Loading v1 for ANSYS 18.0 (registration required). Other versions may be available and can be found in the ANSYS App Store. All ACT extensions come with documentation on how to install and use the extension.