Issue 37

M. Vieira et alii, Frattura ed Integrità Strutturale, 37 (2016) 131-137; DOI: 10.3221/IGF-ESIS.37.18 137 Extensive experimental analyses were produced in order to qualitatively evaluate the dynamic behaviour of the device, specifically on the specimen. Laser vibrometer measurements have confirmed the correct axial and rotational behaviour of the free-end of the specimen. Thermographic imaging comproved that maximum stresses are registered at the middle throat. A three-way rosette type strain gage was installed on the middle throat in order to acquire strains and evaluate the stresses present on this region, confirming the existence of a biaxial stress state. Further research is strongly suggested on this field, specifically on specimen control and behaviour, horn geometry influence on the τ xy /σ y stress ratio and final specimen dimension. A CKNOWLEDGMENTS his research was financed by Fundação para a Ciência e Tecnologia (FCT) under Portuguese National Project PTDC/EMS-PRO/5760/2014. R EFERENCES [1] Bathias, C., Paris, P., Gigacycle Fatigue in Mechanical Practice, Marcel Dekker, New York, (2005) [2] Stanzl-Tschegg, S., Very high cycle fatigue measuring techniques, International Journal of Fatigue, 60 (2014) 2–17, doi:10.1016/j.ijfatigue.2012.11.016. [3] Anes, V., Reis, L., Li, B., Freitas, M., Sonsino, C., Minimum Circumscribed Ellipse (MCE) and Stress Scale Factor (SSF) criteria for multiaxial fatigue life assessment, Theoretical and Applied Fracture Mechanics, 73 (2014) 109-119. doi : 10.1016/j.tafmec.2014.08.008. [4] Vieira, M., Reis, L., de Freitas, M., Ribeiro, A. M. R., Preliminary Evaluation of the Loading Characteristics of Biaxial Tests at Low and Very High Frequencies Procedia Structural Integrity, (2016). DOI: 10.1016/j.prostr.2016.02.027. [5] Lage, Y., Ribeiro, AMR, Montalvão, D., Reis, L., Freitas, M., Automation in Strain and Temperature Control on VHCF with an Ultrasonic Testing Facility Application of Automation Technology in Fatigue and Fracture Testing and Analysis, Peter C. McKeighan and Arthur A. Braun, Eds., STP 1571, (2014) 80–100, doi:10.1520/STP157120130079, ASTM International, West Conshohocken, PA, doi: 10.1520/STP157120130079. T