| 摘要 |
A method of determining the fatigue life of a structure includes the steps of: associating a mathematical equation for total strain amplitude with the structure:Δɛ 2 =σf′E ( 2 N f ) b + ɛ f′ ( 2 N f ) c , where:Δε/2=strain amplitude,σf′=fatigue strength coefficient associated with a material of the structure, b=fatigue strength exponent of the material, E=cyclic modulus of elasticity of the material, 2Nf=number of cycles,εf′=fatigue ductility coefficient of the material, and c=fatigue ductility exponent of the material; reducing the fatigue strength exponent (b) such that an elastic portion of a total strain amplitude curve associated with the equation has a reduced slope to account for variable amplitude loading for the structure; generating a total strain amplitude curve, based upon the mathematical equation:Δɛ 2 =σf′E ( 2 N f ) b reduced + ɛ f′ ( 2 N f ) c , where (breduced) is now the reduced fatigue strength exponent; and determining a fatigue life of the structure, based on the total strain amplitude curve with the reduced fatigue strength exponent. |
