压电晶体最大特征系数切向判定方法

Method of Determining the Cutting Orientationwith Maximum Coefficients of Piezoelectric Crystals

利用特征系数最大的压电晶体切型,可以获得较强的压电效应.给出了一种利用最优化方法确定特征系数最大的压电晶体切向的计算方法.压电晶体各系数矩阵的矩阵元随不同的旋转切割方向而变化,对二次旋转切割,它们是两个旋转角的连续函数.以压电系数为例,给出了二次旋转后各矩阵元的表达式和部分矩阵元随两个旋转角变化的三维曲面.各矩阵元的绝对值均存在一个最大值,有些最大值比原始坐标系中的最大值要大.针对LiNbO3晶体的压电系数矩阵,利用所给出的方法计算了每一矩阵元的最大值和相应的切割方法(2个旋转切角).

A more strongly piezoelectric effect can be obtained by using the cuts of the piezoelectric crystal with the maximum coefficients. The values of the elements of piezoelectric coefficient matrixes change with the different cutting orientation. For the cuts doubly rotated, they are continuous functions of two rotation angles. The absolute value of every matrix element has a maximum. Some of the maximum values are greater than that given in the original coordinate system. The formulas of the elements of the piezoelectric coefficient matrix for the cuts of the crystal LiNbO3 that doubly rotated were obtained. Some curves of the matrix elements about two rotation angles were given. The maximum of each matrix element and the corresponding cuts were calculated by the proposed numerical method.