密肋复合墙板支撑框架结构是由框架与其内部嵌入的密肋复合墙板组成的一种双重抗震结构，框架内部嵌入复合墙板所组成的受力构件，其变形特征不同于普通框架和剪力墙，由此导致结构的自振周期计算方法不能直接按照一般框架-剪力墙结构进行计算。本文以Timoshenko双变量梁理论及协同工作模型为基础，建立了复合墙板支撑框架结构的频率方程，结合边界条件导出了结构的自振周期计算公式，并给出了基本自振周期的近似计算方法。算例分析表明：复合墙板支撑框架结构自振周期受复合板抗剪刚度影响较大，且影响随着振型的增加而增大，高振型时复合墙板剪切变形的影响不可忽略；采用似计算方法计算基本自振周期的误差不大，可以满足工程计算精度要求。

The frame structure with multi-grid composite walls is a dual seismic structure. The deformation feature of the structure is different from common frame or shear wall, and the natural vibration period of the structure can not be calculated with the method for the frame-shear wall structure. Based on the theory of Timoshenko dual variable beam and collaborative work model, the frequency equation for the structure is derived, and the natural period calculation formula is established combined with the boundary conditions of structure. The approximate calculation method for the basic formula is gived simultaneously. Example analysis shows that: the natural vibration period of the structure can be impacted by the shear stiffness of the lightweight composite wallboard significantly, especially to the high order mode. The influence of the shear deformations of the composite wall to the natural vibration period of the high order mode can not be ignored. The error of approximate calculation method by the basic formula is not large comparing with the analytical solution, and can meet the engineering calculation accuracy requirements.