d33

d33 is a designation used in various technical domains, with meanings that depend on the context. In mathematics, D33 (or D_33) denotes the dihedral group of order 66, the symmetry group of a regular 33-gon. This group consists of 33 rotations and 33 reflections and is part of the family of dihedral groups that describe symmetries of regular polygons.

In materials science and engineering, d33 is a piezoelectric coefficient that describes the induced strain in the same direction as an applied electric field. It is a key parameter for evaluating piezoelectric materials and devices such as actuators and sensors. The value of d33 varies with the material, temperature, and crystal orientation.

In other contexts, d33 may appear as a code, variable, or label within standards, catalogs, or software. Its exact meaning in those cases is defined by the relevant documentation or specification. Overall, d33 most commonly appears as either a mathematical group designation or a material property coefficient, reflecting its use in symmetry analysis and electromechanical characterization.