鋳鉄円板の曲げ強度について

抄録

  Bending strength of cast iron circular plates were examined using specimens of various strength, diameter and thickness. Cast iron disks did not fracture at the maximum load, but still supported the load with increasing deflexion. Conventional bending strength σ_bp defined by an elastic formula and the maximum load had good correlation with the tensile strength σ_t. It depended on the thickness of the disk h, but just slightly on diameter D. Thus the following equation was valid experimentally.
    σ_bp=2σ_t+7+100/h (kg/mm²)
The strength of the disk is estimated by
    P_m=σ_bp⋅h²/[3/2π+(1+ν)(0.485C ln (D/2h)+0.52)]
The calculated values well agreed with the experimental values for lathed specimens of σ_t=15∼35kg/mm², h=5∼20mm, D=200∼400mm. The formula was also valid for as cast disks in the region of σ_t<25kg/mm² where σ_t is not the strength of the standard test piece, but is that of the casting.