【摘要】 针对大跨度斜拉空间结构的斜拉索大幅振动问题,考虑塔柱-拉索-空间结构协同作用,导出了拉索在轴向激励作用下的非线性振动方程。采用多尺度法研究拉索大幅振动的各种可能性,运用精细时程积分法数值求解振动方程。研究表明斜拉索自由振动时的振动特性与塔柱、拉索、空间结构三者之间的频率比,以及塔柱、空间结构对拉索所提供的初始扰动特性密切相关;塔柱振动对拉索的参数振动影响明显。若塔柱与空间结构的固有频率相近且远离拉索固有频率,拉索振动发散。若塔柱和空间结构的固有频率相近、且与拉索固有频率存在一定差别,拉索振动呈现“拍”的特点。若塔柱、空间结构与拉索三者的固有频率相互紧密靠近,拉索振动的位移幅值接近拉索的初始扰动值。更多还原

【Abstract】 The dynamic response of cables without damping in cable-stayed spatial structures (CSS) under axial excitation is investigated. The non-linear vibration equations of cables with the consideration of interaction among tower columns, cables, spatial structures are given. The multiple scale method (MSM) is introduced to analyze the characteristics of cable’s vibration, and the precise time-integration method (PTIM) is used to solve vibration equations. It is shown from the results that the characteristics of cable vibration is closely relative to the frequency ratio of tower columns, cables and spatial structures, as well as the initial disturbances caused by the vibration of the tower columns and the spatial structures. The parametric vibration response of cables is significantly influenced by the vibration of tower columns. The divergent vibration arises in the free vibration of cable without damping if the natural frequencies of tower columns and spatial structures are very close, but are far from the natural frequencies of cables. On the other hand, the “beat” feature of cable free vibration occurs, if the natural frequencies between tower columns and spatial structures are approximately the same and slightly different from those of cables. The displacement amplitude of cable vibration is very close to the magnitude of its initial disturbance if natural frequencies among cables, tower columns and spatial structures are almost the same.更多还原