I think would suggest looking up papers on the "dynamic Modulus" see files below.
You also mention "creep-fatigue" test so I suggest you look at this Code of practice. Which gives advice on determining the static modulus from cyclic test data.
As for your problem you can only measure the "static modulus" during a creep-fatigue test and the accuracy of the results will depend on your extensometer and testing/data-logging. If you decide that you really need the "dynamic modulus" to answer your question then I would suggest interrupting the creep-fatigue test and using ultrasonic methods. It will be interesting to see if the dynamic modulus changes during creep-fatigue cycling.
https://en.wikipedia.org/wiki/Dynamic_modulus
http://www.npl.co.uk/publications/elastic-modulus-measurement.
Article Elastic modulus measurement - Obtaining reliable data from t...
Article A Code of Practice for the determination of cyclic stress-strain data
Article Comparison of static and dynamic methods for measuring stiff...
I am not sure if this is what you are asking but, anyway, in case it is helpful, I can tell you the following:
- as you probably know, from static tests you can obtain the (static) elastic modulus (or Young's modulus), a measure of the stiffness of the material or, in other words, a measure of the (elastic) deformation energy stored in the material when loading in the linear elastic region
- when applying dynamic load, you can obtain the dynamic elastic modulus. In the complex modulus approach, the elastic (real) component of the dynamic modulus is called storage modulus, E’, and again is a measure of the deformation energy stored by the material. On the other side, the viscous (imaginary) component of the dynamic modulus is called loss modulus, E”, and accounts for the energy dissipation due to internal friction during relaxation processes
Maybe you identify these with the modulus you are asking about...
If this is so, for measuring them you could use a dynamic mechanical analyser (DMA). The DMA is able to apply a mechanical excitation of selected frequency and amplitude (it can apply stresses/strains that may be very small) under controlled temperature conditions, while recording displacements and stiffness. This allows the evaluation and characterization of intrinsic and extrinsic mechanical properties of the material, namely the (static) elastic modulus, the creep response or the viscoelastic behaviour/dynamic elastic modulus (e.g. the storage modulus, the loss modulus and the loss tangent/mechanical damping) as a function of frequency and temperature. There are several types of clamp that may suite different types of samples.
Regards,
I think would suggest looking up papers on the "dynamic Modulus" see files below.
You also mention "creep-fatigue" test so I suggest you look at this Code of practice. Which gives advice on determining the static modulus from cyclic test data.
As for your problem you can only measure the "static modulus" during a creep-fatigue test and the accuracy of the results will depend on your extensometer and testing/data-logging. If you decide that you really need the "dynamic modulus" to answer your question then I would suggest interrupting the creep-fatigue test and using ultrasonic methods. It will be interesting to see if the dynamic modulus changes during creep-fatigue cycling.
https://en.wikipedia.org/wiki/Dynamic_modulus
http://www.npl.co.uk/publications/elastic-modulus-measurement.
Article Elastic modulus measurement - Obtaining reliable data from t...
Article A Code of Practice for the determination of cyclic stress-strain data
Article Comparison of static and dynamic methods for measuring stiff...
Thanks to Jose Ignacio Rojas Gregorio and Michael William Spindler for your valuable information.
This is one of the question now I am looking for. Thanks for all of you.
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