## C. Dealing with materials properties: CPIEZO, MPIEZO, PPIEZO

With the help of the CPIEZO tool,the user can display properties of the materials stored in his materialsdatabase. It is not a complete tool, but it can help for simple cases. In any case,the values provided by the MATERIAL entry in the data file are the best placeto look. Depending on the number of properties, a given material is defined aselastic, fluid or piezoelectric/magnetostrictive.

The syntax of the command is:

cpiezo MAT

where MAT is the material’s name.

For an elastic material, the longitudinal and transversespeeds are displayed.

For a fluid material, the longitudinal speed is displayed.

For a piezoelectric (magnetostrictive) material, it isassumed that the material belongs to the crystalline class 6mm. The constants sE,sD, cE, cD, d, g, h, e, eS, eT; bS and bT (sH, sB, cH,cB, d, g, h, e, mS, mT; cS and cT) and the coupling factors k33, k13,k15, and kT are displayed.

The user can create lossy piezoelectric or magnetostrictivematerials from non-lossy ones, by specifying loss factors on the three mainconstants blocks (MPIEZO program).

The user can check that a piezoelectric or magnetostrictivematerial is effectively lossy (dissipating, not absorbing heat) (PPIEZO program).