ULTRASONIC-RHEOLOGICAL METHOD FOR DETERMINING THE DYNAMIC THRESHOLD FORCE IN MATERIALS WITH PLASTIC-TYPE BEHAVIOUR

摘要

The invention relates to an ultrasonic-rheological method for determining the dynamic threshold force in materials with plastic-type behaviour, comprising: coupling an ultrasonic transducer to the lower plate of a torsional rheometer with parallel plate geometry, b) adjusting the distance between plates of the rheometer to a gap of between 0.1 and 1 mm, c) introducing the sample of material with plastic-type behaviour between the rheometer plates fitted in the previous step, d) initiating the emission, by the transducer, of longitudinal ultrasonic waves at a frequency interval of between 0.1 and 20 MHz, and e) synchronising said acoustic emission with the rheological test consisting of subjecting the sample to the action of a mechanical stress.