The core contents of digital power transmission network are to build the true three dimension scene of objective region , to search for the transmission equipments and to operate them in the scene interactively . according to the two main kinds of three dimension digital models ( earth surface model and transmission equipment model ) , this thesis describes a simplifying method depended on view - point : it accomplishes displaying and flying over a large area of true earth surface with level of detail model based on block - binary tree . and it realizes " the efficient display of abundant data of equipment models and interactive management by the method of combination of models and images 构建目标区域的真实三维场景，并在场景中对输电设备进行查询和交互操作是数字输电网络的核心内容，本文针对数字平台中两种主要的三维数据模型? ?地表模型及输电设备模型提出了基于视点的简化方法：用块? ?二叉树结构的动态细节层次模型解决了大区域真实地形的显示及漫游方法；用失栅结合的方式实现了对海量设备模型数据的高效显示及交互管理的功能。
A detailed model of non - linear parametric excitation vibration coupling the stay cable and the girder , in which the static sag as well as the geometric non - linearity are considered , is proposed in this paper . based on several numeric examples investigated by the galerkin method composed with the integration strategy , several kinds of factors effecting stay cable parameter vibration are studied . another parameter vibration model by the axial excitation is presented and the corresponding nonlinear equations are derived 本文创新地提出了斜拉桥拉索-桥面耦合参数振动模型，推导了索-桥耦合非线性参数振动方程组，联合galerkin法及数值积分方法，对各种特性的拉索进行了数值求解，得出了影响拉索参数振动的各种因素；提出了斜拉索受轴向端激励参数振动模型，导出了模型的非线性振动方程，使用谐波平衡法得出了产生参数振动需要的最小激励幅值、共振时瞬态及稳态的振动幅值及索拉力的变化特性，并用数值积分方法对实际斜拉桥拉索进行了计算，分析了拉索阻尼对参数振动的影响。
