Pii: S0020-7225(99)00118-4

The asymptotic expansion technique is used to obtain the two-dimensional dynamic equations of thin micropolar elastic plates from the three-dimensional dynamic equations of micropolar elasticity theory. To this end, all the ®eld variables are scaled via an appropriate thickness parameter such that it re ̄ects the expected behavior of the plate. A formal power series expansion of the three-dimensional solution is used by considering the thickness parameter as a small parameter. Without any a priori assumption on the form of the ®eld variables, it is shown that the zeroth-order approximation simultaneously includes both the plate equations previously presented in the literature and the standard assumptions on the speci®c forms of the ®eld variables. Some aspects of the present asymptotic plate equations are also discussed. Ó 2000 Elsevier Science Ltd. All rights reserved.