抄録
The stress and displacement fields near the bonding edge, sharp notch, and contact edge show singularity behaviors, so methods of evaluating the strength of these points using maximum stresses calculated by a numerical stress analysis, such as the finite element method, are generally not valid. We have previously presented a new method of evaluating the strength of these singular points using two stress singularity parameters H and λ. The difficulty with this method was in obtaining the critical value of the intensity of the stress singularity parameter H<th> for each order of stress singularity λ. Then we have developed a method of formularizing stress-singularity parameter H<th> for each order of stress singularity λ by utilizing two typical strength parameters, namely, fatigue limit σ<w0> and threshold stress-intensity factor range ΔK<th>. The critical H<th> (λ) value agrees well with the experimentally measured value. Using this easily obtained critical H<th> (λ) value, we estimated the fretting-fatigue-crack initiation criteria for any contact edge angle and optimized the contact-edge geometry. Moreover, we can apply this new strength criteria to stress-singularity fields for general stress-concentration structures.
