Abstract
This paper describes a novel method to model the stress gradient effect in fretting-fatigue. The analysis of the mechanical fields in the proximity of the contact edges allows to extract nonlocal intensity factors that take into account the stress gradient evolution. For this purpose, the kinetic field around the contact ends is partitioned into a summation of multiple terms, each one expressed as the product between nonlocal intensity factors, Is, Ia, Ic, depending on the macroscopic loads applied to the mechanical assembly, and spatial reference fields, ds, da, dc, depending on the local geometry of the part. This description is obtained through nonintrusive post-processing of FE computation and is conceived in order to be easily implementable in the industrial context. By using as input the macroscopic load, the procedure consists in computing a set of nonlocal stress intensity factors, which are an index of the severity of the stress field in the proximity of the contact edges. This description has two main advantages. First, the nonlocal stress intensity factors are independent from the geometry used. Secondly, the procedure is easily applicable to industrial scale FE model..
Highlights
C omputational models for fatigue damage analysis in presence of a steep stress gradient still remain poorly effective
The kinetic field around the contact ends is partitioned into a summation of multiple terms, each one expressed as the product between nonlocal intensity factors, Is, Ia, Ic, depending on the macroscopic loads applied to the mechanical assembly, and spatial reference fields, ds, da, dc, depending on the local geometry of the part
The first main problem is related to the fact that fretting-fatigue introduces a severe stress gradient at the contact interface that depends on the local geometry of the part
Summary
C omputational models for fatigue damage analysis in presence of a steep stress gradient still remain poorly effective This is the case of fretting-fatigue where a local stress concentration is introduced by contacting components experiencing small amplitude relative motion. As a consequence the mechanical fields generated close to the contact edge and the ones arising at the crack tip are comparable This analogy can be exploited to apply the mathematical tools already developed for fracture mechanics to fretting fatigue. The analogy between crack and contact problems is justified Both reference fields are normalized in order to correspond to the displacement field obtained at the crack tip during an elastic loading phase with either ΔKI or ΔKII equal to 1MPa. Figure 3: radial and tangential evolution of da.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
