系泊浮桥运动的非线性动力特性

研究系泊分段线性恢复刚度对浮桥运动的影响，根据系泊浮桥的分段线性刚度，提出了浮桥动力响应的非线性分析模型．考虑浮桥的横荡运动，计算上下游锚链的系泊力及确定分段线性刚度，建立了浮桥横荡运动方程．以长1000m的浮桥为例，得到了浮桥横荡周期为4．33s，及不同波浪作用下浮桥横荡运动响应的幅频特性．计算表明，由于系泊刚度的分段线性，浮桥运动出现幅值跳跃，并且刚度比越大，幅值跳跃越大．

Nonlinear Dynamic Behavior for Motion of the Moored Floating Bridge

The nonlinear response behaviors of moored floating bridge suffered from wave-current were investigated, and the nonlinear analytical model of dynamics response for floating bridge was presented based on the piece-wise linear stiffness of chains.The mooring forces in the two sides of the floating bridge and the piece-wise linear stiffness were solved by considering sway motion of the bridge,and the sway equations were established for the bridge.The period 4.33 s of sway motion for the bridge of 1 000 m was obtained and the amplitude-frequency response characteristics of the sway motion of floating bridge were given.It is shown that due to piece-wise linear stiffness of mooring chains the jumps of motion amplitudes occur, and the bigger is the ratio of stiffness between the first section and second section,the bigger is the jump of amplitude.