Universal dynamic testing. (Hardware/Software).

Dynamic mechanical analysis consists of applying a dynamic stress and measuring the corresponding strain to calculate the intrinsic viscoelastic properties of a specimen of rubber. Servo-hydraulic dynamic testing machines allow users to apply customized tests combining various transient or periodical conditions on either final products or specimens of material. The Viscoanalyzer series (VA2000-VA3000 and VA 40000) includes Multidyn testware offering a dynamic machine type mode that allows full use of the system's analysis potential. Contrary to the classical DMA mode where the excitation signal is sinusoidal, but the strain signal is often not purely sinusoidal due to the non-linear behavior of the rubber, Multidyn makes it possible to control in real time the waveform of the true excitation applied to the specimen. Excitation waveforms such as sine, half sine, haversine, etc., are available, as well as the capability to apply a pre-recorded specific excitation shape, for example a real road response. A harmonic analysis of the material's response may then give much more information on the complex and highly non-linear behavior of rubbers. Simple dynamic and/or static tests, as well as customized experiments defined as a succession of different chained test sequences, are possible, offering scientists any combination of analysis that may approach the typical real life conditions representative of the future use of the final product. Then, shear modulus and tangent delta measurement, Payne effect, glassy transition determination, thermal expansion coefficient, fatigue tests, creep and stress relaxation may be measured with one single Viscoanalyzer. (Metravib R.D.S., 200, Chemin des Ormeaux F-69578, Limonest, Cedex, France)

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