Rivet Joint Calculator
Verify a transversely loaded riveted joint: from the transverse force, rivet diameter, rivet count, arrangement and plate thickness the tool derives the shear of the rivets and the bearing pressure at the thinnest plate, each with a safety factor against the allowable stresses, live with every input.
Rivet calculator (shear, bearing pressure)
Model: static check of a transversely loaded riveted joint against allowable stresses (shear τ = F/(z·n·A), bearing σ_l = F/(z·d·t)). Even load distribution over all rivets assumed. No check of edge distance, hole weakening, fatigue or friction grip. Note: in lightweight design, self-pierce riveting and clinching are modern alternatives to classic riveting.
Results
Calculating …
Formulas and fundamentals
The riveted joint transfers a transverse force F that is distributed evenly over z rivets. The shear check compares the mean shear stress τ = F/(z·n·A) with the allowable shear stress. Here A = π·d²/4 is the rivet cross-section (governed by the rivet shank or hole diameter) and n is the number of shear planes per rivet: single shear n = 1, double shear n = 2. Double shear halves the shear stress because the force is split over two shear planes per rivet.
The bearing pressure check (contact) verifies that the rivet does not press unacceptably into the hole wall. Related to the projected area d·t, σ_l = F/(z·d·t); the governing value is always the thinnest effective plate t. The limit is the allowable bearing pressure of the plate material, which is usually a multiple of the allowable shear stress. The available safety factor in each case is the ratio of allowable to acting value, S = allow/act.
Both checks run in parallel: the joint is only adequate when shear and bearing pressure are satisfied. For thick plates and few rivets the shear usually governs, for thin plates the bearing pressure. Not covered are the tension check of the plate cross-section weakened by the holes and the edge distance (tear-out to the edge), which must be checked additionally.
Worked example
Given: A single-shear rivet row transfers a transverse force F = 20,000 N over z = 4 rivets of diameter d = 10 mm. The thinnest effective plate is t = 8 mm thick. The allowable values are τ_zul = 140 N/mm² and σ_l,zul = 280 N/mm².
Shear: The rivet cross-section is A = π·10²/4 = 78.54 mm². With single shear (n = 1) this gives τ = 20,000/(4·1·78.54) = 63.66 N/mm². Against τ_zul = 140 N/mm² the safety factor is S = 140/63.66 = 2.2 – the shear check is satisfied.
Bearing pressure: σ_l = 20,000/(4·10·8) = 62.5 N/mm². Against σ_l,zul = 280 N/mm² the safety factor is S = 280/62.5 = 4.5. Both checks are well in the green range; the joint is adequately sized. With a double-shear arrangement the shear stress would be halved to 31.8 N/mm².
Frequently asked questions
What do single shear and double shear mean for rivets?
The number refers to the shear planes per rivet: in single shear two plates with one interface lie against each other and the rivet is sheared at one location (n = 1). In double shear the central plate lies between two straps, giving two shear planes (n = 2). The double-shear arrangement halves the shear stress and avoids the eccentric force offset of the single-shear interface.
Why is the bearing pressure related to the thinnest plate?
Because the bearing pressure σ_l = F/(z·d·t) decreases with plate thickness t: the thinnest effective plate has the smallest projected contact area and thus the highest pressure. It is the weakest link of the bearing contact and determines the safety factor. Thicker plates are uncritical.
Which check usually governs?
For thick plates and few rivets the shear is often critical, for thin plates the bearing pressure. The calculator reports both separately and marks the governing value, so the smallest safety factor is immediately visible. In addition, the edge distance and the weakened plate cross-section must be checked.
Are rivets still up to date?
Classic hot or solid rivets have largely been replaced by bolts in steel construction. In lightweight design, however, forming-based joining methods such as self-pierce riveting and clinching are widespread because they need no pre-drilled hole, join dissimilar and coated materials and are easy to automate. For static rough sizing the same basic checks of shear and bearing pressure apply.
Does the calculator cover fatigue and friction grip?
No. The check is static against the allowable stresses and assumes an even load distribution over all rivets. Under cyclic load a fatigue check is required; the friction grip of preloaded joints (e.g. slip-resistant connections) and the hole weakening of the tension cross-section are not considered.