Impulse excitation technique for dynamic flexural measurements at moderate temperature

Abstract

The impulse excitation technique (IET), which is presently a precise and reliable technique for measuring dynamic moduli at room temperature, has been adapted to measure dynamic flexural modulus at temperatures in the range of 25° to 300 'c. This modified technique involves a sensitive microphone and electronics to record and analyze the sound waves emitted from a specimen vibrating in the fundamental flexural mode. The fundamental resonant frequency and geometry of the specimen are used to obtain the modulus. The location ofthe microphone relative to the specimen is critical and is a major factor once the specimen is placed within the heated environment. Problems were identified and solved, and test data for aluminum are presented to support the modification ofthe lET for use at elevated temperatures.

Mechanical properties of nanostructured silicon carbide consolidated by spark plasma sintering

“…First, the Young's modulus (E) was obtained from room temperature (RT) to 1000 • C in neutral atmosphere by a dynamic resonant frequency method 25,26 (Grindo Sonic apparatus, LEM-MENS Inc.) using rectangular bars, with a similar geometry to the bending tests specimen described below. Impulse excitation was done by means of an electro-pneumatic shock on the bottom side of the specimen.…”

Measurement of the Young's modulus in particulate epoxy composites using the impulse excitation technique

“…On the contrary, a simple and low cost technique well-known as impulse excitation technique (IET) accomplishes all the experimental needs for a correct measurement of the E parameter. Basically, IET measurements provide the E modulus through the resonant frequency of the vibration of a normalized beam generated by a punctual impact on a sample of the material under test [2][3][4][5][6][7]. Measurements in different materials have been carried out using IET [5][6][7].…”

Properties of zirconia-toughened-alumina prepared via powder processing and colloidal processing routes

“…Bars were set into free vibration by striking and an impulse excitation frequency tester (GrindoSonic, Lemmens Elektronica BV, Belgium) was used to measure the resonant frequency. This frequency, along with the length, thickness, and density of the bars were used in the following equation to calculate Young's modulus [8]:…”