矩形 b=50, h=100 mm, V=20000 N → τ_max = 6 MPa A = b·h = 5000 mm²。τ_avg = V/A = 4 MPa。τ_max = 1.5·V/A = 6 MPa @ 中性轴。{"result":"Rectangle b=50 mm, h=100 mm, V=20000 N. A = b·h = 5000 mm². τ_avg = V/A = 4 MPa. τ_max = 1.5·V/A = 6 MPa at the neutral axis.","metadata":{"input":{"shape":"rectangle","V":20000,"b":50,"h":100},"result":{"shape":"rectangle","shearStress":6,"shearStressUnit":"MPa","avgShear":4,"avgShearUnit":"MPa","area":5000}}}
实心圆 D=100 mm, V=20000 N → τ_max ≈ 3.3953 MPa A = π·D²/4 = 7853.98 mm²。τ_avg ≈ 2.5465 MPa。τ_max ≈ 3.3953 MPa @ 中性轴。{"result":"Solid circle D=100 mm, V=20000 N. A = π·D²/4 = 7853.9816 mm². τ_avg = V/A = 2.5465 MPa. τ_max = 4·V/(3·A) = 3.3953 MPa at the neutral axis.","metadata":{"input":{"shape":"circle","V":20000,"D":100},"result":{"shape":"circle","shearStress":3.3953,"shearStressUnit":"MPa","avgShear":2.5465,"avgShearUnit":"MPa","area":7853.9816}}}