Recording materials mechanical strength

The tensile strength and stress of the IPMC are measured in the same manner as those of the IP. The bending stiffness of a fully hydrated IPMC sample is estimated using the free oscillation attenuation method. By bending the sample to the appropriate initial displacement, the free vibration response can be recorded. The natural frequency of the cantilever, is obtained from the fast Fourier transform of the free vibration response curve. The stiffness of the IPMC, Egg, is determined using Eq. 4, which is based on the thin cantilever beam theory of material mechanics ... 

The results of tensile tests recorded allow for obtaining the mechanical properties of the materials studied. The Young s modulus of both materials was calculated from oi (stress at a strain of 0.0005) and 02 (stress at a strain of 0.0025) according to the standard UNE-EN ISO 527-1. Tables 2 and 3 shown the Young s modulus and the tensile strength obtained of the tensile tests. The other mechanical properties used were density y = 7850 kg/rrP and Poison ratio u = 0.3. 

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