6 根 Ø16 mm → A = 1206.4 mm² A₁ = π·16²/4 = 201.06 mm²。A = 6 × 201.06 = 1206.37 mm²。周长 = 50.27 mm。理论重 = 1.58 kg/m。{"result":"6 bars of Ø16 mm. Single-bar area = π·16²/4 = 201.06 mm². Total area = 1206.37 mm². Perimeter per bar = 50.27 mm. Unit weight = 1.58 kg/m.","metadata":{"input":{"diameterPreset":"16","count":6},"result":{"diameter":16,"count":6,"perBarArea":201.06,"totalArea":1206.37,"perimeter":50.27,"unitWeight":1.58,"unit":"mm²"}}}
4 根 Ø20 mm,12 m → A = 1256.6 mm²,W = 118.4 kg A₁ = 314.16 mm²。A = 1256.64 mm²。理论重 = 2.47 kg/m。总重 = 118.38 kg。{"result":"4 bars of Ø20 mm, length 12 m. Single-bar area = π·20²/4 = 314.16 mm². Total area = 1256.64 mm². Perimeter = 62.83 mm. Unit weight = 2.47 kg/m. Total weight = 118.38 kg.","metadata":{"input":{"diameterPreset":"20","count":4,"length":12},"result":{"diameter":20,"count":4,"length":12,"perBarArea":314.16,"totalArea":1256.64,"perimeter":62.83,"unitWeight":2.47,"totalWeight":118.38,"unit":"mm²"}}}