||ACORD-Express: Check of traditional trusses
The aim is to check, according to design criteria (strength, buckling) and according to service criteria (deformations), the main members of traditional trusses (principal rafter, hip or valley rafter and tie-beam). The total loads, the wood volume, the paint surfaces, the lengths and weights of the members are determined.
|Overview of the structure
|The offered possibilities depend in first instance on the shape of the building in which the truss is inserted: portion with 1 slodowelg side, portion with 2 slodowelg sides, L-shaped portion with hip, L-shaped portion with valley, L-shaped portion with hip and valley, four-slodowelg side roof.
It should be noticed that this choice has an influence not only on the type of truss geometry available in the software but also and primarily on the load transfer automatically computed by ACORD-Express. The loading surfaces depend on the shape of the roof.
Then, regarding the type of truss itself, the following choices are available: truss with collar beam, truss with tie brace, king-post truss, classical truss, A-shaped truss, half truss and beam on two supports. According to your choice, you can in addition specify the number of knee braces and/or of bracings.
Eventually, the definition of the truss is completed by the following data:
- Environmental parameters (moister content…)
- Wood category
- Cross-sectional dimension of each member (rectangular section, grooved or doubled sections)
- Initial cambers of principal rafters and tie-beam
- Truss supports (resting, with shoe or imbedded in masonry…)
- Spacing between trusses
- Number of purlins
We would like to stress that ACORD-Express is the first
software to ask for the dimensions from the technical drawing directly as user input. Until now, the carpenter had to input the distances between neutral axes and the intersection points of these axes. In a nutshell, while the user used previously to have to calculate by hand the position of the model points, it is no longer necessary!
Floor service load (optional):
|Dead loads of the roof and optionally of the floor: in both cases, you have the choice between two input modes. In the first mode, you choose in predefined lists the various components attached to the roof or the floor. The total load is then automatically computed. In this case, for the roof, you can select the nature of the roof covering, the fastening system, the plates and insulation components, etc…, then for the floor, the partition elements, the flooring, the insulation and suspended ceiling etc… In the second mode, you input directly the desired total load.
Snow load: You have the choice between three distinct methods to specify the snow loads, either using the map from the standards, or you select the standard zone, or you input directly the desired values. To complete the snow load definition, you specify the altitude of the construction, then still using predefined lists, you select the various parameters to be considered such as the presence of snow retaining structures, the exposition coefficients, etc…
Using lists, you select only the category of the building (dwelling, office, etc…) and the use of the floor (floor, attic, etc…). The load is then automatically determined. Please note that you always remain free to input specific load values at all time.
the load combination and the various factors included in these combinations are automatically determined without further user input.