压电电荷常数 d

决定压电效应程度的一种特性参数。d 的定义因效应类型（正效应或逆效应）而略有不同。

效应	符号	说明	适用场合	单位
正效应	d^E	恒定电场 E 下的 d — 每单位施加应力所产生的电位移	用作接收器的换能器；加速度计	Coulomb/N
逆效应	d^T	恒定应力 T 下的 d — 每单位施加电场所产生的应变	用作发射器的换能器	m/volt

尽管 d^T 和 d^E 的单位不同，但它们在国际单位制（S.I.）中的数值是相同的（参见 Berlincourt (3)，公式 24a，第 188 页）。其数值取决于压电材料的类型、极化后经历的时间以及局部条件（例如温度、电场强度、静态应力等）。该数值还取决于应力-应变或电场相对于极化方向的取向。对于换能器，最常用的是 d₃₃（即平行取向），有时也会使用 d₃₁（即垂直取向）。

另见其他压电特性。

Piezoelectric charge constant d

A property that determines the degree of piezoelectric effect. d is defined somewhat differently depending on the type of effect (direct or inverse).

Effect	Symbol	Description	Applicability	Units
Direct	d^E	d at constant electric field E — dielectric displacement developed per unit of applied stress	Transducers used as receivers; accelerometers	Coulomb/N
Inverse	d^T	d at constant stress T — strain developed per unit of applied electric field	Transducers used as transmitters	m/volt

Although d^T and d^E have different units, their numerical values in the S.I. system are identical (see Berlincourt (3), equation 24a, p. 188). The value depends on the type of piezoelectric material, the time since poling, and local conditions (e.g., the temperature, electric field strength, static stress, etc.). The value also depends on the orientation of the stress-strain or electric field with respect to the poling direction. For transducers d₃₃ (i.e., parallel orientation) is most common although d₃₁ (i.e., perpendicular orientation) is sometimes used.

Also see other piezoelectric properties.