残留応力の測定について (第2報)

熱処理をした中実および中空円筒の残留応力の測定について

抄録

The author reported, in the first report, a method of measurement of the residual stress in the heat treated solid cylinder with small diameter, consisting of the removal of surface layer of the specimen by corrosion and the measurement of the resultant changes of the length in axial direction and the specific volume of the remaining portion. In the present report, the author shows a method of measurement of the residual stress in the heat treated hollow or solid cylinder when the inner layer of the specimen is removed.
Let ₀σ_z, ₀σ_t and ₀σ_r be the residual stresses in the axial circumferential and radial direction respectively, further let ε_z and ε_v be the changes of axial strain and volume strain accompanied by removal.
Then the three stresses ₀σ_z, ₀σ_t, ₀σ_v are expressed as follows:
₀σ_z=E/1+ν{(f_b-f)d/df(ε_z+ν/1-2νε_v)-(ε_z+ν/1-2νε_v)}
₀σ_t=-E/1+ν{(f_b-f)d/df(ε_z-1/1-2νε_v)-(f_b+f)/2f(ε_z-1/1-2νε_v)}
₀σ_v=-E/1+νf_b-f/2f(ε_z-1/1-2νε_v)
where, E=Young's modulus.
ν=Poission's ratio.
f_b=Cross sectional area in the outer diameter of cylinder.
f=Removed area.
The change of volume strain ε_v is, when we put v₀ and v for the specific volume of the specimens before and after removal.
ε_v=2(1-2ν)/3(1-ν)(v-v₀)/v₀
The procedure and the actual data of measurement are explained. The effect of boring by cutting is also reported.