The single plate connection, or shear tab, is one of the simple shear connections set out in Part 10 of the AISC Manual, and a fabricator favourite because it is the cheapest of the group: one plate, one weld line, one bolt group.
La piastra viene sempre saldata in officina al supporto e normalmente imbullonato sul campo alla trave di collegamento. It can be welded to the beam instead on a shop-assembled frame. What you should not do is put that weld in the field: field welding is labour-intensive and expensive next to running a bolt in.
Due tipi di configurazione
Which configuration you are in decides which rules apply, and it follows from the geometry rather than from a setting you choose.
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Configurazione convenzionale
- È consentita una sola fila verticale di spit. Il numero di bulloni nella connessione deve essere compreso tra 2 e 12.
- La distanza dalla linea dei bulloni alla linea di saldatura deve essere uguale o inferiore a 3-1/2 pollici.
- Fori standard (malattie sessualmente trasmissibili) o fori orizzontali ad asola corta (HSSL) sono consentiti per essere utilizzati come indicato nella tabella 10-9 del manuale AISC XV Edizione.
- La distanza dal bordo verticale deve soddisfare i requisiti della tabella J3.4 delle specifiche AISC. La distanza dal bordo orizzontale deve essere maggiore o uguale a 2d sia per la piastra che per l'anima della trave, dove d è il diametro del bullone.
- Lo spessore della piastra o lo spessore dell'anima della trave devono soddisfare il requisito di spessore massimo indicato nella tabella 10-9 del manuale AISC XV Edizione.
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Configurazione estesa
- Il numero di bulloni non è limitato.
- La distanza dalla linea di saldatura alla linea di bulloni più vicina al supporto non è limitata.
- L'uso dei fori deve soddisfare i requisiti della sezione J3.2 delle specifiche AISC.
- Le distanze dal bordo orizzontale e verticale devono soddisfare i requisiti della tabella J3.4 delle specifiche AISC.
Designing a Single Plate Connection in SkyCiv
The design code can be AISC 360-16 ASD o LRFD, and units English/Imperial or SI/Metric. Orientation is BCF, BCW o BBW; hover the tooltip for what each one means. Clicca il “Piatto unico” piastrella.
Scheda Dettagli
Record the project details here. None of it changes the calculations, but it carries into the report.
Scheda assemblaggio
Three tabs sit under Assembly: the Girder, the Beam, and the Connection, which holds the single plate.
Scheda trave
Specify the section and material grade of the supporting member. A992 and A36 are in the list; for anything else choose Custom and enter Fy and Fu.
Scheda Trave
The same inputs for the beam, plus cope dimensions, beam clearance and the difference in elevation.
For BBW orientation the coping is worked out automatically, and you can override it. The automatic cope recalculates whenever you change the beam section, the girder section, the clearance or the difference in elevation.
The clearance is also what puts you in one configuration or the other. A clearance small enough that the beam still sits inside the girder will usually give a conventional single plate, unless the girder flange is wide enough that the distance from the bolt to the girder web exceeds 3-1/2″. A clearance that puts the beam completely outside the girder flange gives an extended single plate. For the difference in elevation, a positive value means the beam is above the girder and a negative value below.
Scheda Connessione
Set the plate properties: grade A36 or A992, or Custom with your own Fy and Fu, then the plate width ‘b’, height ‘h’ and thickness ‘thk’.
Watch the 3D renderer as you go. The plate height should sit within the beam depth, and the plate width has to be wide enough for the beam to bolt or weld to, which matters most in an extended configuration.
Infisso 1 Scheda
Infisso 1 is the plate to beam web connection. It can be bolted or welded; this walkthrough uses bolted.
Primo, the bolt hole types at the beam and at the plate. Fabricators usually ask for standard holes (malattie sessualmente trasmissibili) in the beam and horizontal short-slotted holes (HSSL) in the plate, which buys fitting tolerance in the field. Note that those two are also the only hole types the conventional configuration permits, so reaching for oversized holes moves you into the extended configuration rules.
Successivamente, the bolt material or grade: A307, A325, A490 or Custom. A325 and A490 are grades within ASTM F3125, which consolidated the older standalone specifications. Choose N or X for a bearing-type connection and SC for slip-critical.
Slip-critical joints have lower design bolt capacity than bearing-type, so use them where slip actually matters: oversized or slotted holes, load reversal, or fatigue. Between N and X, X gives the larger bolt shear capacity, but the threads must be excluded from the shear plane, and the erector has to know that. Between SC(A) and SC(B), SC(B) gives the larger capacity and requires a more thoroughly prepared faying surface, for example SSPC-SP6 commercial blast cleaning.
Then the bolt diameter, from 5/8″ to 1-1/2″ or the metric equivalents, and the arrangement, fino a 12 file e colonne di bulloni, with the row and column spacing.
Worth knowing: if you need more bolt group capacity, opening up the spacing can do it instead of adding bolts, as long as the plate height still fits within the beam depth. The bolt group strength uses the instantaneous centre of rotation method (ICOR), so a wider spacing is credited with the capacity it actually provides. Check with your fabricator first, though. Many prefer 3″ spacing typical throughout.
La “bordo” input is the distance from the beam end to the first bolt column.
Scorso, the erection gap. This is the gap that lets the beam be dropped into place on site. It costs capacity, so specify it only where erection actually needs it.
Infisso 2 Scheda
Infisso 2 is the plate to support connection, whether that support is a girder web, a column flange or a column web. For a single plate this is welded only.
Specify the weld material, or ‘Custom’ with your own Fnw if the electrode is not listed, then the weld size. For single plate connections the weld needs to be at least 5/8 volte lo spessore della piastra, so that the weld develops the plate.
That rule has a cost consequence worth planning around. tavolo 8-12 del Manuale AISC XV Edizione, . 8-126, shows a large jump in weld passes between 5/16″ and 3/8″ filetto: 5/16″ needs a single pass, 3/8″ needs three. A 1/2″ plate needs only a 5/16″ fillet to develop it, which keeps you in single-pass territory. So if the connection is short of capacity, increase the plate height to the maximum allowable before you increase the thickness. A thicker plate demands a larger weld, and a larger weld means more passes, more deposited metal and more labour time.
Scheda Carichi
Enter the vertical shear under ‘Fy’.
Match the load to the design method you picked at the start. LRFD takes factored loads against design strength; ASD takes service loads against allowable strength. The software cannot tell which you typed.
Scheda Risultati
Clic “Esegui controlli di progettazione”. Anything missing from the earlier tabs is flagged here rather than silently defaulted.
The summary shows whether the connection passed, with a utilization ratio against each check. Se ha fallito, change the inputs on the earlier tabs and click “Rieseguire i controlli di progettazione”. When it passes, “View Calculation Report” opens the detailed report.
That is an extract from the report. Each check carries its reference to the AISC manual or specification, and the working follows the order the specification uses, so a reviewing engineer can read it line by line instead of reverse-engineering a number.
Ecco una copia in PDF del rapporto di calcolo dettagliato completo: Rapporto di progettazione della connessione.
Try It Yourself
Pick the single plate, enter your sections, plate and shear, and see every check with its code reference. Funziona nel browser, with nothing to install.
See also the single plate connection calculator, il double angle calculator, che per il connessioni a taglio overview.
