Bolted Joint Analysis
Check the capacity of a single bolt in a connection subjected to shear and tension per BS EN 1993-1-8. Includes bolt shear, bearing, tension, combined interaction, and net section checks.
About This Calculator
This calculator checks a single bolt and its connected plate under shear and tension against the design resistances of EN 1993-1-8 Table 3.4, covering the main failure modes in one pass so the governing check is clear. Checks: bolt shear, α_v f_ub A_s / γ_M2 per shear plane, multiplied by the number of shear planes (α_v = 0.6 for grades 4.6, 5.6 and 8.8, or 0.5 for 4.8, 5.8, 6.8 and 10.9 with threads in the shear plane); plate bearing, k_1 α_b f_u d t / γ_M2, with α_b and k_1 worked out from the end and edge distances; bolt tension, 0.9 f_ub A_s / γ_M2; the net section of the plate at the hole, 0.9 A_net f_u / γ_M2; and combined shear and tension, F_v,Ed / F_v,Rd + F_t,Ed / (1.4 F_t,Rd) ≤ 1. Each check is reported as a utilisation so the critical mode stands out. Inputs are the bolt diameter, hole size, tensile stress area, ultimate strength and shear factor, the number of shear planes, the plate thickness, width, end and edge distances and ultimate strength, the partial factor γ_M2 (1.25 in the UK National Annex), and the design shear and tension per bolt. Assumptions and limits: a single bolt acting as both an end bolt and an edge bolt. Block tearing, punching shear, prying action, slip-resistant (preloaded) connections, long joints and the distribution of load around a bolt group are outside its scope. Typical uses: preliminary sizing of bolted steel connections, checking cleats, splice plates and brackets, and confirming which failure mode governs before a full connection design.
Referenced Standards
- BS EN 1993-1-8, Eurocode 3: Design of joints
- SCI P358, Joints in Steel Construction: Simple Joints to Eurocode 3