Ultrasonic fatigue testing device under biaxial bending
Journal Title: Frattura ed Integrità Strutturale - Year 2016, Vol 10, Issue 37
Abstract
A new fatigue testing device has been developed to test specimens under biaxial loading at 20 kHz. A flat smooth specimen with a disc geometry is placed on a torus frame and cyclically loaded at the center of its upper face. Disc bending generates a biaxial proportional stress state at the center of the lower face. Any positive loading ratio can be applied. A cast aluminum alloy (used to produce cylinder heads) has been tested under biaxial bending using this device in order to determine its fatigue strength at 109 cycles under high hydrostatic pressure. Self-heating is moderate but macroscopic fatigue cracks after testing are very long. First results in VHCF regime are consistent with literature results obtained under similar stress state but in HCF regime and at 20 Hz.
Authors and Affiliations
C. Brugger, P. Osmond, T. Palin-Luc, M. Blanc
Compliant actuation based on dielectric elastomers for a force-feedback device: modeling and experimental evaluation
Thanks to their large power densities, low costs and shock-insensitivity, Dielectric Elastomers (DE) seem to be a promising technology for the implementation of light and compact force-feedback devices such as, for...
Dynamic rock fragmentation: thresholds for long runout rock avalanches
The dynamic fragmentation of rock within rock avalanches is examined using the fragmentation concepts introduced by Grady and co-workers. The analyses use typical material values for weak chalk and limestone in o...
3D-mixed-mode-loading: material characteristic values and criteria’s validity
In many structures and components cracks, which are exposed to a 3D-mixed-mode-loading, occur due to multiaxial loading situation. A reliable evaluation of those components requires fracture mechanical criteria v...
A comparative study on dynamic mechanical performance of concrete and rock
Recently, engineering blasting is widely applied in projects such as rock mineral mining, construction of underground cavities and field-leveling excavation. Dynamic mechanical performance of rocks has been g...
Critical crack path assessments in failure investigations
This paper presents a case study in which identification of the controlling crack path was critical to identifying the root cause of the failure. The case involves the rupture of a 30-inch (0.76 m) natural gas pip...