The dynamic theory of piezoelectric materials with voids is intended for applications to natural and artifical materials with distributed voids, some bioengineering materials and intelligent materials. Therefore, it plays an important role in the development and application of modern new materials. But the energy principles in dynamic theory of piezoelectric materials with voids,which the principle of virtual work, the reciprocal theorem and various variational principles are not yet established systematically.rn According to the basic idea of classical yin-yang complementarity and modern, dual-complementarity, in a simple and unified way proposed by Luo[6,7], the energy principles in dynamic theory of piezoelectric materials with voids can be established systematically. In this paper, an important integral relation in terms of convolutions is given, which can be considered as the generalized principle of virtual work in mechanics. Based on this relation, it is possible not onlyto obtain the principle of virtual work and the reciprocal theorem in dynamic theory of piezoelectric materials with voids, but also to derive systematically the complementary functionals for eleven-field, nine-field, six-field and three-field simplified Gurtin-type variational principles by the generalized Legendre transformations given in this paper. Furthermore, with this approach, the intrinsic relationship among various principles can be explained clearly. In this paper first applying the principle of virtual work, one may obtain the reciprocal theorem in dynamic theory of piezoelectric materials with voids avoiding both the use of the Laplace transform and the incorporation of the initial conditions into the equations of motion. Obviously this method given in this paper is even simpler and directer than the conventional method.rn The energy principles (the principle of virtual work, the reciprocal theorem and various simplified Gurtin-type variational principles) established in this paper are an important part of dynamic theory of piezoelectric materials with voids. Obviously, the simplified Gurtin-type variational principle can fully characterize the initial-boundary-value problem of this dynamics. Consequently, the energy principles proposed in this paper will be of great value both in theoretical studies and in the establishment of various approximate methods and approximate engineering theories.%根据古典阴阳互补和现代对偶互补的基本思想，通过作者早已提出的一条简单而统一的新途径，系统地建立了微孔压电弹性动力学的能量原理.给出一个重要的以卷积表示的积分关系式，可以认为，在力学上它是广义虚功原理的表式.从该式出发，不仅能得到微孔压电弹性动力学的虚功原理和互等定理，而且通过作者所给出的一系列广义Legendre变换，能系统地导出成互补关系的11类变量、9类变量、6类变量和3类变量简化Gurtin型变分原理的泛函.同时，通过这条新途径，还能清楚地阐明这些原理之间的内在联系.
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