Split-ring and shear-plate connections
A bolted joint with split rings or shear plates in the side grain of the members, by NDS 2024 Chapter 13 with the adjustment factors of Chapter 11. LRFD or ASD.
Inputs of the connection #
- Connectors: 2-1/2 in. split rings on 1/2 in. bolts, 4 in. split rings on 3/4 in. bolts, 2-5/8 in. shear plates on 3/4 in. bolts, or 4 in. shear plates on 3/4 or 7/8 in. bolts. Only the 4 in. shear plate offers a choice of bolt; it sets the metal limit of Table 13.2B footnote 2 (4,400 or 6,000 lb). Bolts, or lag screws with their penetration into the main member in shank diameters (Table 13.2.3 sets Cd).
- Connectors in a row and rows: a row runs along the load (11.3.6.2). Each connector on each bolt in each shear plane is one unit.
- Members: two members (one shear plane) or three (the main member with connectors on both faces). The side members are wood, or steel plates with shear plates. The species gives G, and G gives the species group of Table 13A. Net thickness and width set the tabulated value and the gross areas of the group action factor; E is for the group action factor.
- Load angle to grain: in the main member, and in a wood side member at its own angle.
- Spacing, end and edge distances: spacing in a row and between rows, the end distance from the square-cut end of the main member, whether the main member is in tension or compression at that end, and the unloaded and loaded edge distances. The values entered are for the main member; if a side member is tighter, enter its values.
- Loads: dead, live, snow and wind along the connection, combined by ASCE 7-22. Service conditions: moisture (Table 11.3.3) and temperature (Table 11.3.4). Load duration factors and the live-load time effect factor are in the code options.
Auto-design (editor toolbar) varies the connectors in a row and the number of rows, and the connector when you unlock it. Objective: the fewest connectors.
Checks performed #
| Check | Basis |
|---|---|
| Member thickness at least the tabulated minimum | NDS 13.2.2.1 (not feasible below it) |
| Reference P and Q per unit | Tables 13.2A, 13.2B by group, thickness and faces with connectors, interpolated between rows (13.2.2.2); the lower of the two members joined |
| Lag screw penetration | Table 13.2.3, Cd interpolated between 0.75 and 1.0 |
| Steel side plates | Cst on P of 4 in. shear plates (Table 13.2.4); the metal limits of Table 13.2B footnote 2 |
| Load at an angle to grain | Hankinson, Eq. 13.2-1, in each member at its own angle |
| Geometry factor CΔ | Table 13.3, interpolated between the minimum and the full value; at an angle, separate factors on the parallel and perpendicular components and the spacing of Eq. 13.3-1 with Table 13.3.2.2; the least for any connector applies to all (13.3.2) |
| Group action Cg | Eq. 11.3-1 with γ = 500,000 lb/in. (4 in.) or 400,000 lb/in. (2-1/2 in. rings, 2-5/8 in. plates), gross areas; a member loaded across the grain by its thickness times the width of the group (11.3.6.3) |
| Connection capacity | units × N' against the load, every combination with its CD (≤ 1.6) or KF φz λ (λ ≤ 1.0 for connections) |
The drawings are the joint elevation (connectors, bolts, end distance, spacing, edge distances, the side member behind) and a section through a connector row.
Limitations #
- Connectors in end grain or on sloping cuts (13.2.6, 13.3.3) are not offered.
- The members are not checked: net section at the connector grooves (3.1.2, Appendix K), local stresses (13.3.4.3, Appendix E), and the members themselves. Neither is a steel side plate or the bolt bearing on it.
- The geometry entered applies to the main member; a side member with tighter distances is your check.
- The one-third increase of the shear plate metal limits for wind and seismic (footnote 2) is not applied. For LRFD, the limit is converted with KF φz λ; that form is to be confirmed against the code text.
- Two grooves cut concentric in one surface (13.3.4.2) are not offered.
Verification examples #
Verification status: 21 values compared in 12 examples (9 published, 3 hand calculations from the cited equations): 21 within tolerance, 0 recorded deviations. Code basis: not yet recorded for this module.
The tabulated values and group action factors are NDS 2024's own tables: Table 13.2A and 13.2B rows (including the 4,400 lb limit of a 4 in. shear plate on a 3/4 in. bolt), and four entries of Table 11.3.6B. Thickness interpolation, the load at 45° and the geometry factor between the minimum and the full distances are hand calculations. No free worked example of a split-ring or shear-plate connection is on disk. AWC's Structural Wood Design Examples are listed as needed.