1. CALCULO DEL CENTROIDE PLASTICO
 CALCULO DE ÁREAS DE ACERO
𝐴𝑠′ = 6𝑐𝑚2
𝐴𝑠′′ = 4𝑐𝑚2
𝐴𝑠 = 8.52𝑐𝑚2
 CALCULO DE LA CARGA
𝑃𝑜 = 0.85 𝑓′𝑐 ( 𝑏𝑡) + (𝐴𝑠+ 𝐴𝑠′+ 𝐴𝑠′′)𝑓′𝑦
𝑃𝑜 = (0.85 ∗ 210 ∗ 30 ∗ 50) + (18.52 ∗ 4200)
𝑃𝑜 = 345534 𝑘𝑔
 MOMENTO INTERNO
𝑀𝑜𝑚𝑒𝑛𝑡𝑜 𝐼𝑛𝑡𝑒𝑟𝑛𝑜(1) = 𝑓′𝑦 ∗ 𝐴𝑠′ ∗ 𝑑′ = 4200 ∗ 6 ∗ 40 = 1008000
𝑀𝑜𝑚𝑒𝑛𝑡𝑜 𝐼𝑛𝑡𝑒𝑟𝑛𝑜 (2) = 𝑓′𝑦 ∗ 𝐴𝑠′′∗ 𝑑′′ = 4200 ∗ 6 ∗ 30 = 504000
𝑀𝑜𝑚𝑒𝑛𝑡𝑜 𝐶𝑜𝑛𝑟𝑒𝑡𝑜 = 0.85 ∗ 𝑓′𝑐 ∗ 𝐴𝑔 ∗ 𝑏𝑟𝑎𝑧𝑜 = 0.85 ∗ 210 ∗ (30 ∗ 50) ∗ 20 = 5355000
𝑆𝑢𝑚𝑎𝑡𝑜𝑟𝑖𝑎 𝑑𝑒 𝑀𝑜𝑚𝑒𝑛𝑡𝑜𝑠 𝐼𝑛𝑡𝑒𝑟𝑛𝑜𝑠 = 𝑀𝐼(1) + 𝑀𝐼(2) + 𝑀𝐼(3) = 6867000
 MOMENTO EXTERNO
𝑀𝑜𝑚𝑒𝑛𝑡𝑜 𝐸𝑥𝑡𝑒𝑟𝑛𝑜 = 𝑃𝑜 ∗ 𝑋𝑠 = 345534 𝑋𝑠
 IGUALDAD DE MOMENTOS
𝑀𝑜𝑚𝑒𝑛𝑡𝑜 𝐸𝑥𝑡𝑒𝑟𝑛𝑜 = 𝑀𝑜𝑚𝑒𝑛𝑡𝑜 𝐼𝑛𝑡𝑒𝑟𝑛𝑜
345534 ∗ 𝑋𝑠 = 6867000
𝑋𝑠 = 19.873 𝑐𝑚