Configurations de test
(En anglais seulement) Dynamic mechanical properties can be assessed from the response of a material subjected to a periodic stimulus which can be applied axially (tension/compression), or in shear (planar or torsion). These properties are usually expressed in terms of complex dynamic modulus with storage and loss modulus components. The storage modulus can be associated with the stiffness of a material, while the loss modulus is associated with the loss of energy within the sample through plastic deformation, internal friction, relative molecular motions, relaxation processes, phase transitions, morphology changes, etc. Thus, the dynamic properties provide information at the molecular level to understand the mechanical behavior of the material. The evaluation of the dynamic mechanical properties is particularly useful in the characterization of materials showing non-elastic properties such as viscoelasticity or poroelasticity, where properties vary with frequency.
Voir : Module de laboratoire — Torsion d’échantillons en forme de disqueLab Modules · 9 chapitres · 21:26
Préparez les disques de caoutchouc et d’hydrogel, réalisez les essais de torsion et analysez les résultats.
(En anglais seulement) This feature is used to obtain the Frequency, Amplitude and Offset of a sinusoidal signal. A blue line displays the theoretical sinusoid with the Frequency, Amplitude and Offset obtained (Figure 1). The values of the Frequency, Amplitude and Offset are indicated in the "Results" field. The units vary according to the graph’s axes.
This feature can also be used for sinusoidal stimulus-response analysis. Sinusoidal stimulus shall be selected on the x-axis and the sinusoidal response on the y-axis. The Modulus is the ratio of the response Amplitude over the stimulus Amplitude. The Phase is the phase difference between the response and the stimulus. The Modulus’ is computed as the Modulus*Cos(Phase) and the Modulus” is computed as the Modulus*Sin(Phase). A blue line displays the theoretical sinusoidal stimulus-response with the Frequency, Modulus and Phase obtained (Figure 2). The values of the Modulus and Phase are indicated in the “Results” field. The units vary according to the graph’s axes.
One use for this feature would be to compute material properties by multiplying the Modulus obtained by the appropriate geometric factors. For example, the Young’s Modulus can be obtained during uniaxial compression or tension on cylindrical sample with t/pi*r2 as the geometric factor, t is the thickness and r is the radius of the sample.
Mach-1 Analysis – Sinusoid – Exemple d’analyse stimulus-réponse
Mach-1 – Exemple de données brutes (Image Sin 2mm 0.2Hz 5cycles)
Mach-1 – Exemple de données brutes (Image of Sin 2mm 0.1Hz 5cycles)
LAB MODULE – Torsion of Disk-Shaped Samples – Student Version
