The ultimate recipient of the load is the shell itself. Part VII focuses heavily on calculating the localized stresses induced in the cylindrical shell. It helps engineers determine if the shell thickness is sufficient or if a reinforcing pad (repadv) is required to prevent tearing or buckling. Why AISI E-1 Volume II Part VII Makes Designs Better
This article dissects AISI E 1-16 (or latest edition) Volume II, Part VII, explaining its requirements for cold-formed steel framing connections and, more importantly, how adhering to this part of the AISI specification elevates anchor bolt chair design from a mere spacer to a critical load path component.
The standard provides precise empirical definitions for every component of the anchor chair assembly. AISI E-2 Anchor Bolt Chair | PDF - Scribd
The top plate must feature adequate width and clearance to accommodate heavy-duty hydraulic torque wrenches or tensioning jacks. A chair that is perfectly optimized on paper but impossible to fabricate or tighten in the field is a failure of practical design.
(Top-Plate Length): The length of the plate in the radial direction. (Top-Plate Thickness): The thickness of the top plate. aisi e 1 volume ii part vii anchor bolt chairs better
| Requirement | Detail | |-------------|--------| | | Anchor bolt chairs for axial load-bearing CFS columns (typically 33–68 ksi steel) | | Design loads | Tensile + shear interaction, eccentricities included | | Material | Minimum Fy = 33 ksi (usually 50 ksi for better performance) | | Thickness | Typically ≥ 54 mil (1.37 mm) for chair elements | | Welding | Must comply with AWS D1.3; fillet welds sized per AISI S100 | | Bearing | Concrete bearing strength under chair base (0.85 f’c) | | Anchorage | Anchor bolt edge distance, embedment, and nut/washer configuration per ACI 318 |
While the AISI formulation is considered a reliable standard, modern engineering practices suggest several ways to optimize or "better" the performance and durability of these chairs: 1. Optimization of Chair Geometry : Increasing the height (
Designing steel structures like storage tanks and silos requires precision, particularly when managing overturning forces from wind or seismic activity. AISI E-1, Volume II, Part VII Go to product viewer dialog for this item.
An anchor bolt chair is a specialized structural assembly consisting of a top plate, vertical gussets (or side plates), and an optional base plate. The ultimate recipient of the load is the shell itself
Vertical vessels, chimneys, and storage tanks experience severe overturning moments from environmental forces. Standard anchor bolts cannot always connect directly to a thin cylindrical shell without causing severe localized stresses. Anchor bolt chairs solve this problem by:
While intermittent welding might pass structural calculations, continuous fillet welds provide superior fatigue resistance and prevent moisture entrapment, minimizing crevice corrosion behind the chair assembly.
Creating a rigid platform (top plate) for the anchor bolt nut.
While high-quality anchor bolt chairs may have a higher upfront cost compared to makeshift rebar chairs or wooden templates, they prevent "site-fix" costs that can skyrocket. Why AISI E-1 Volume II Part VII Makes
Using the AISI E-1 method provides several engineering advantages: Localized Stress Reduction
Ensures the plate is thick enough to resist bending from the bolt nut without prying.
By relying on the rigorous engineering frameworks established in , structural engineers ensure a design that is safe, compliant, and built to last. When it comes to the safety of industrial steel construction, adhering to these proven specifications is undeniably the better choice. How Can We Assist You Further?