{ "title": "Large-deflection cantilever under a dead tip load against the elastica (solids)", "kind": "theory", "source": "The elastica of a cantilever under a vertical end load: K. E. Bisshopp, D. C. Drucker, Large deflection of cantilever beams, Quarterly of Applied Mathematics 3(3):272–275, 1945 (elliptic-integral solution); values computed by integrating θ″ = −(P/EI) cos θ by shooting (our own RK4, 20000 steps), agreeing with the table of K. Mattiasson, Numerical results from large deflection beam and frame problems analysed by means of elliptic integrals, IJNME 17(1):145–153, 1981, to all six digits", "quantities": [ { "id": "v1", "quantity": "tip deflection δ_v/L at P L²/(E I) = 1", "measure": { "command": "solve.probe", "params": { "step": "K1", "at": [ [ 10.0, 0, 0.25 ] ] }, "pointer": "/nodes/0/displacement/2", "scale": -0.1 }, "value": 0.301721, "tolerance": { "relative": 0.01 }, "reason": "hex20, 40 × 2 through the depth, L/h = 20: shear deformation (0.6 (h/L)² ≈ 0.15 % of the deflection) and the clamp's local restraint, both absent from the elastica" }, { "id": "u1", "quantity": "tip shortening δ_h/L at P L²/(E I) = 1", "measure": { "command": "solve.probe", "params": { "step": "K1", "at": [ [ 10.0, 0, 0.25 ] ] }, "pointer": "/nodes/0/displacement/0", "scale": -0.1 }, "value": 0.056433, "tolerance": { "relative": 0.02 }, "reason": "as δ_v; the shortening is the smaller, second-order quantity, so its relative error is about twice the deflection's" }, { "id": "v2", "quantity": "tip deflection δ_v/L at P L²/(E I) = 2", "measure": { "command": "solve.probe", "params": { "step": "K2", "at": [ [ 10.0, 0, 0.25 ] ] }, "pointer": "/nodes/0/displacement/2", "scale": -0.1 }, "value": 0.493457, "tolerance": { "relative": 0.01 }, "reason": "hex20, 40 × 2 through the depth, L/h = 20: shear deformation (0.6 (h/L)² ≈ 0.15 % of the deflection) and the clamp's local restraint, both absent from the elastica" }, { "id": "u2", "quantity": "tip shortening δ_h/L at P L²/(E I) = 2", "measure": { "command": "solve.probe", "params": { "step": "K2", "at": [ [ 10.0, 0, 0.25 ] ] }, "pointer": "/nodes/0/displacement/0", "scale": -0.1 }, "value": 0.160642, "tolerance": { "relative": 0.02 }, "reason": "as δ_v; the shortening is the smaller, second-order quantity, so its relative error is about twice the deflection's" }, { "id": "v5", "quantity": "tip deflection δ_v/L at P L²/(E I) = 5", "measure": { "command": "solve.probe", "params": { "step": "K5", "at": [ [ 10.0, 0, 0.25 ] ] }, "pointer": "/nodes/0/displacement/2", "scale": -0.1 }, "value": 0.713792, "tolerance": { "relative": 0.01 }, "reason": "hex20, 40 × 2 through the depth, L/h = 20: shear deformation (0.6 (h/L)² ≈ 0.15 % of the deflection) and the clamp's local restraint, both absent from the elastica" }, { "id": "u5", "quantity": "tip shortening δ_h/L at P L²/(E I) = 5", "measure": { "command": "solve.probe", "params": { "step": "K5", "at": [ [ 10.0, 0, 0.25 ] ] }, "pointer": "/nodes/0/displacement/0", "scale": -0.1 }, "value": 0.387628, "tolerance": { "relative": 0.02 }, "reason": "as δ_v; the shortening is the smaller, second-order quantity, so its relative error is about twice the deflection's" }, { "id": "v10", "quantity": "tip deflection δ_v/L at P L²/(E I) = 10", "measure": { "command": "solve.probe", "params": { "step": "K10", "at": [ [ 10.0, 0, 0.25 ] ] }, "pointer": "/nodes/0/displacement/2", "scale": -0.1 }, "value": 0.810609, "tolerance": { "relative": 0.01 }, "reason": "hex20, 40 × 2 through the depth, L/h = 20: shear deformation (0.6 (h/L)² ≈ 0.15 % of the deflection) and the clamp's local restraint, both absent from the elastica" }, { "id": "u10", "quantity": "tip shortening δ_h/L at P L²/(E I) = 10", "measure": { "command": "solve.probe", "params": { "step": "K10", "at": [ [ 10.0, 0, 0.25 ] ] }, "pointer": "/nodes/0/displacement/0", "scale": -0.1 }, "value": 0.554996, "tolerance": { "relative": 0.02 }, "reason": "as δ_v; the shortening is the smaller, second-order quantity, so its relative error is about twice the deflection's" } ] }