摘 要：在圆形三向网架非线性动力学基本方程的基础上，用拟壳法给出了圆底扁球面三向网壳的大挠度方程和非线性动力学基本方程。在固定边界条件下，引入了异于等厚度壳的无量纲量，对基本方程和边界条件进行无量纲化。并将扁球面网壳的大挠度解当作扁球面网壳的初始缺陷，通过Galerkin作用得到了一个含二次、三次的非线性动力学方程。通过求Melnikov 函数，给出了具有初始缺陷的扁球面网壳系统可能发生混沌运动的临界条件。并通过数字仿真绘出了平面相图，证实了混沌运动的存在并且可以通过改变参数来抑制系统混沌运动的发生。同时也发现了考虑初始缺陷的扁球面系统固有频率增大了，从而发生混沌运动的临界载荷值减小了。

Abstract: On the basis of the nonlinear dynamical foundational equations, the big deflection equation and the nonlinear dynamic equation of the shallow spherical shells were established by the method of quasi-shells. Dimensionless quantity of shells with uniform thickness was introduced and simplified the foundational equations and the boundary conditions under the fixed boundary conditions. First the big deflection is taken as the initial imperfect of the system and a nonlinear dynamic differential equation including the second and third order is derived by the method of Galerkin. The critical conditions of that chaos motion are given by solution the Melnikov function. Using the digital simulation plotted the plane phase and it approved existence of the chaotic motion and controlled the chaos。 Finally, it is found that the natural frequency of shallow reticulated spherical shells considering initial imperfect becomes bigger and the critical value of chaotic motion is smaller.