BS ISO 22605:2020 pdf free.Refractories一Determination of dynamic Young’s modulus (MOE) at elevated temperatures by impulse excitation of vibration.
BS ISO 22605 A test specimen of suitable geometry is heated up to the test temperature and allowed to stabilize at this temperature. It is then excited mechanically with a single elastic strike by an adequate impulse tool (Method A).Alternatively, the test specimen is heated up (resp. cooled down) at a low heating rate (resp. cooling rate) to the test temperature, excited mechanically with a single elastic strike by an adequate impulse tool at regular intervals and the fundamental resonant frequency values are determined (Method B).A vibration signal detector (e.g. non-contacting microphone or laser vibrometer) senses the mechanical vibrations in the specimen resulting from the excitation and transforms the vibrations into electrical
signals. Specimen supports, impulse locations and signal pick-up points are selected to induce and measure a specific mode of transient vibrations, i.e. the flexural mode. The signals are analysed and a signal analyser that provides data about the frequency and/or the period of the specimen’s vibration determines the fundamental resonant frequency. The appropriate fundamental resonant frequency,dimensions and mass of the specimen are then used to calculate the dynamic Young’s modulus at this test temperature.This test method is appropriate for determining the modulus of elasticity of refractory bodies that are homogeneous in nature.This method addresses the determination of the dynamic moduli of elasticity of slender rectangular
bars and cylindrical rods.This test method is non-destructive in use, so it may be used on specimens prepared for other tests. The specimens are subjected to only minute strains; hence the moduli are measured at or near the origin of the stress-strain curve with a minimum possibility of specimen fracture. The test provides options for variations in test specimen sizes and procedure to accommodate most refractory compositions and textures.The impulse excitation test method utilizes an impact tool (hammer) and simple supports for the test specimen.
This test method is not suitable for specimens with major cracks or voids.This test method is limited to determining moduli of specimens with regular geometries, such as rectangular parallelepipeds and cylinders, for which analytical equations are available to relate geometry, mass and modulus to the resonant vibration frequency.BS ISO 22605 pdf download.