Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
An experimental investigation on the fatigue behaviour of 304L stainless steel notched member subjected to axial-torsional loading
Submission Author:
Cainã Bemfica de Barros , DF , Brazil
Co-Authors:
Cainã Bemfica de Barros, Fábio Castro
Presenter: Cainã Bemfica de Barros
doi://10.26678/ABCM.COBEM2021.COB2021-0226
Abstract
This work investigates the axial-torsional fatigue and cyclic plasticity of notched 304L stainless steels specimens at room temperature. Fully reversed force- and torque-controlled axial, torsional and axial-torsional nonproportional loading paths were investigated, with fatigue lives ranging from 10^2 to 10^6 cycles. For selected specimens, rosette strain-gauges were placed at the notch root to investigate the local strains. The evolution of local strains is consistent with the cyclic hardening behaviour observed in thin-walled tubular specimens. An initial cyclic softening is observed and may be followed by secondary hardening due to martensitic transformation. Measurable plastic strains were observed for all tests, including those that did not fail after 10^6 cycles. A post-mortem analysis of the fracture surface indicates that multiple crack initiation sites were observed for axial, torsional and nonproportional loading for low fatigue lives (<10^5 cycles). Moreover, the failure mechanism under torsional loading depends on the fatigue life regime: for lower fatigue lives, fatigue cracks exhibited orientations that correspond to the plane of maximum normal stress, whilst orientations corresponding to the plane of maximum shear stress were observed for longer fatigue lives (>10^5 cycles).
Keywords
304L stainless steel, notched components, multiaxial fatigue
