How
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is pattern or skip loading run in SAFE
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?
In SAFE v12, "Answer: Pattern or skip loading is run in SAFE by defining an Auto Pattern Live " Load case is added which currently apply the Live load type on load case (Figure 1), which applies area loading to each slab panel and , then combine the forces envelope using Range Combo which is described as follows:
Add "Auto Pattern Live" case after Live type load is defined in the model.
For example, create a template model of 4x4 bays, add LPAT1 case of "AUTO PATTERN LIVE" type and run the analysis. Look at the LPAT1 load case using Display > Show Loads, select LPAT 1 Case and choose the option for Analysis Model load. Program is creating 16 patterns where each panel is loaded with Live load as shown below.
The results are combined from 16 patterns using Range Combo. The pattern load combo is created using Range type combination which automatically includes the all possible pattern or skip loading cases i.e., loading from the adjacent spans, alternate span etc. to produce enveloping solution. Click here to find the details of Range combo in SAP2000 and SAFE v12 program. The final results are shown below:
The slab panels are currently identified based on Cartesian Grid System only. In future, automatic trace of supports will be added which will help to identify panels for more complex structures.
using the Range-add load combination to envelope response from all possible load combinations. When the Load Type is Auto Pattern Live, SAFE loads each slab panel defined by the intersection of orthogonal grids with a separate automatically created pattern live load pattern. The magnitude of these load patterns is based on the sum of all defined live and reducible live load patterns. These load patterns are created when an analysis is performed. The live load in these patterns is not reduced.
Figure 1 - Auto Pattern Live definition
For example, a slab with a 4x4 bay arrangement may be created from a template, then subjected to the Auto Pattern Live load case named LPAT1, which will generate 16 load patterns, one for each slab panel. Once analysis is run, the load case may be viewed by selecting Display > Show Loads > LPAT1 > Analysis Model Load, as shown in Figure 2:
Figure 2 - Load patterns
The range-add load combination then envelopes the solution to consider all possible combinations of pattern or skip load cases which may result from the 16 load patterns. Enveloped results are shown in Figure 3:
Figure 3 - Enveloped results
Slab-panel geometry is based on the Cartesian grid system. Future releases will enable automatic tracing of support objects to provide for more complex panel geometry.
Attachments
- Auto pattern live model (FDB file)
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