{ "title": "Natural frequencies of a cantilever (Euler–Bernoulli)", "kind": "theory", "source": "Euler–Bernoulli beam: f_n = (β_n L)²/(2π L²)·√(EI/ρA), β₁L = 1.8751, β₂L = 4.6941; Timoshenko, Young and Weaver, Vibration Problems in Engineering, 4th ed., Wiley 1974, §5.3", "quantities": [ { "id": "f1", "quantity": "first bending frequency (modes 1 and 2 are the y and z pair)", "measure": { "from": "modes", "pointer": "/modes/0/frequency" }, "value": 0.012770863695053732, "tolerance": { "relative": 0.01 }, "reason": "Euler–Bernoulli neglects shear and rotary inertia, which lower f1 by about 0.2% at L/h = 20" }, { "id": "f1_pair", "quantity": "the other first bending frequency", "measure": { "from": "modes", "pointer": "/modes/1/frequency" }, "value": 0.012770863695053732, "tolerance": { "relative": 0.01 }, "reason": "as f1: a square section bends alike in y and z" }, { "id": "f2", "quantity": "second bending frequency", "measure": { "from": "modes", "pointer": "/modes/2/frequency" }, "value": 0.08003363662360005, "tolerance": { "relative": 0.02 }, "reason": "shear and rotary inertia lower the second mode by about 1% at L/h = 20 (Timoshenko)" } ] }