中文摘要：

在大跨度桥梁设计中，抗风是工程师们最关心的问题之一，也是桥梁动力稳定问题的重要研究领域。本文按照广义力和广义位移之间的对应关系，将相空间的弹性动力学的基本方程乘上相应的虚量，然后积分，代数相加，并考虑到体积力和面积力均为伴生力，建立了适用于研究大跨度桥梁流固耦合初值问题相空间的两类变量的广义拟余能原理。应用该原理，解决了一个非保守桥梁流固耦合问题的具体算例。并且讨论了如何应用非保守系统的广义拟变分原理进行大跨度桥梁近似计算的问题。

英文摘要：

In the design of long-span bridges, one of the most be concerned problems is wind-resistance, which is an important field of dynamic stability of bridges. In the paper, according to the corresponding relations between generalized forces and generalized displacements, the basic equations of elasto-dynamics in phase space are multi- plied by corresponding virtual quantities, integrated and then added algebraically. Considering that body forces and surface forces are both fellow forces, the generalized quasi-complementary energy principles with two kinds of varia- bles of non-conservative systems are established for initial value problems in the fluid-solid coupling problem of the long-span bridges in phase space. A concrete calculation example of the fluid-solid coupling problem in the non- conservative system of bridge has been presented by using this theory. Also the problem about how to deal with the approximate calculation of long-span bridges by dint of the generalized quasi-variational principles in non-conservative systems is discussed.