|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Fatigue in Materials: Fundamentals, Multiscale Modeling and Prevention
||Miniaturised Ultrasonic Fatigue Testing in Torsion
||Tinger Wen, Jicheng Gong, Angus J. Wilkinson
|On-Site Speaker (Planned)
We have developed a novel ultrasonic (20 kHz) testing methodology capable of probing very high cycle regimes in reasonable time frames (10<SUP>8</SUP> ~ 1.4 hours), on small volumes of material spanning 50-200 μm. Bending modes have been used to generate fully reversed uniaxial stress states. We have now extended the sample design to access twisting modes by offsetting the inertial block to one side of the symmetry axis of the cantilever. Dynamic elastic finite element analysis was used to design the detail of the sample shape and analyse the resulting stress distributions. A testing campaign on 304L stainless steel has revealed a dramatic difference between fatigue lives in torsion compared to bending when presented in terms of maximum shear stress amplitudes. This implies the normal stress across the maximum shear stress plane (present in bending but not in torsion) has a large effect in reducing the crack initiation lifetime.
||Planned: Supplemental Proceedings volume