Engineering F.A.Q.
What kind of buildings can be designed?
Our truss engineering module is used in residential and light commercial buildings.
What kind of buildings it can be used?
Light gauge steel typically has capacity up to 3 floors, with more floors hot rolled steel or concrete is needed. I have seen quite complex truss layouts in AU projects where loads are transferred from valley trusses above to trusses below and then again to trusses below and finally to girder trusses in same level. All these trusses are in roof layout and in contact with each other or connected using our connection tools. Rafters may transfer part of load and be supported by trusses.Load transfer from floor to floor is not supported. Bottom chords have been continuous without any knee, but top cords may have multiple knees. In-plane trusses may also be ply trusses like girders usually are.
Will it optimize the structure?
Truss engineering is a checking tool, it do not optimize member sections or diagonal locations, but it can optimize connection fasteners.
How the software behaves if the design fails?
If truss fails then user have to adjust panel spacing or modify truss layout to pass less load to truss, changing section is not a choice in many cases because many customers have only one roll former. Truss framer has rules to set verticals or diagonal connections into bearing locations which are in many cases critical locations. Also design criteria like bracing interval has huge effect to flexural-torsional buckling of compressed members which in many cases is limiting capacity of top cord or compressed diagonals.
Which Vertex versions supports the engineering?
Steel-au and howick-au are most driven environments and can be used for testing in-plane and out-of-plane trusses. Current steel-eu has only support for in-plane trusses.
What kind of cross sections can be used?
Sections need some engineering parameters and we only have limited set of lipped C-sections. C-section with out lips is not supported. Section dimensions, corner rounding, gauge and grade are needed to solve section engineering parameters. We use our own tool to solve these parameters for Eurocode and external program called ColdSteel4600 developed by university of Sydney for AU building code.
Roof truss engineering is affected a lot by wind and snow loads and therefore implementing new code for truss engineering involves also implementing new wind code. Wind local pressures are complex to solve by hand and too much work is needed to define correct wind load by hand to every roof location. Snow loads are more easy to estimate by hand and we haven't built any tools for those. In most countries qualified engineer should sign truss engineering and therefore our truss engineering tool is used as preliminary engineering tool. Our new FEA development gives tools to engineer to check trusses in very detail level. If used truss engineering model in FEA and in our truss engineering tool are equal then an engineering result is same. FEA module engineering do not check connections.
What kind of software options are needed?
Truss engineering needs only option 129 Truss design. FEA needs options 161 FEM Beam Analysis for building engineering model solve stresses and option 162 Building Codes for Beam FEA for capacity check.
Is training needed?
Some training is needed before using truss engineering. Drafter should understand that model should be correct where bearing walls are and snug contact is needed between building components to enable correct load transfer. Drafter should check after truss engineering the results. In checking process applied loads should be in correct magnitude and supports located in correct locations. Overhang is also critical location because open section easily twist. Boxing or other reinforcement is usually needed. Juho can give you more precise answer to need of training. It is best to start with some kind of pilot project with customer because there are so many details involved in truss engineering and drafters have different level of understanding how structures work under different loading and support/bracing conditions.