Considerations for each mode of geometry

Shear mode is also an easy mode to use, with minimal sample precautions required. Only samples having a modulus 10 Pa or less can be tested in this mode, since higher modulus materials would be too stiff in this geometry. 

Tension mode generally gives good results, but it is complicated by the need to superimpose a static force on the dynamic, in order to establish correct measurement conditions. The same is true for compression mode. This topic is discussed fiilly in Section 4.3.4. 

Three-point bending is the best choice of geometry for acciuate modulus determination. In fact, testing an accurately machined steel sample (ordinary steel, not stainless) is certainly the best way of verifying a DMAs modulus measuring accuracy. Despite this, a poor choice of sample dimensions or displacement amplitude can yield results which are wrong. First, it is best that no sample is over 5 mm in width. It is very hard to clamp or uniformly load wide 

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