Estimating the effect of punching on out-of-plane bending fatigue of steel sheet specimens
2025 (English)In: Engineering Failure Analysis, ISSN 1350-6307, E-ISSN 1873-1961, Vol. 173, article id 109415Article in journal (Refereed) Published
Abstract [en]
Sheet metal punching is an important process in manufacturing of heavy-duty vehicle chassis components. The cut edges have a detrimental effect on high cycle fatigue life in uniaxial- and in-plane-bending but the reduction is less pronounced in out-of-plane bending. This paper aims to explain the reduced process sensitivity in out-of-plane bending fatigue, to quantify the high cycle fatigue life reduction at different load ratios, and to propose a methodology for fatigue life estimation. This could enhance the possibilities to identify critical load cases of chassis components, to judge whether fatigue life improving post-processes are necessary, and to locate critical initiation sites for fatigue. Fatigue testing of punched and polished specimens was conducted, and the punching process and four-point bending were simulated using FEM. The results were used to estimate crack initiation site, fatigue life reduction, and for validating the predictions. Fatigue life reduction is found to increase with increased load ratio, but to a smaller extent than expected. A contributing factor the reduced tensile residual stresses due to plasticity during the first load cycle. The reduced process sensitivity as compared to uniaxial fatigue could be explained by the separate locations of crack initiation and high tensile residual stresses in the cut edge. Specimen orientation seems to have a minor influence on the fatigue life. Only improving the outer surfaces, and not the central parts of the cut edge, could increase the high cycle fatigue life for pulsating and reversed loading.
Place, publisher, year, edition, pages
Elsevier BV , 2025. Vol. 173, article id 109415
Keywords [en]
Bending, Heavy-Duty Vehicle (HDV), High Cycle Fatigue (HCF), Punching, S500MC
National Category
Applied Mechanics Vehicle and Aerospace Engineering
Identifiers
URN: urn:nbn:se:kth:diva-360897DOI: 10.1016/j.engfailanal.2025.109415ISI: 001435166500001Scopus ID: 2-s2.0-85218426472OAI: oai:DiVA.org:kth-360897DiVA, id: diva2:1942560
Note
QC 20250317
2025-03-052025-03-052025-03-17Bibliographically approved