斜拉跨越结构的风载影响分析

Effect of wind load on stay-cables across structure

利用有限元分析软件对木龙河斜拉索跨越结构在风载荷作用下的动静态力学特性进行了分析.静态分析表明,风力小于3级时桥的最大位移和最大应力随风力变化不大.风力大于3级时两者随风力的增大而显著增加.通过模态分析得到了跨越结构的前10阶振型和频率,并分析了8级动态风载下管桥中部和端部两个关键节点的位移和拉应力的时间历程响应及某一时刻跨越结构的应力、位移分布情况,最后得到了动态风载荷下风力与最大应力和最大位移之间的关系,得出的结论与静态一致,但在大于3级的风力情况下,动态风载引起的最大位移和最大应力比静态风载约大2倍.

The dynamic and static mechanical performances of the stay-cables structure across Mulong River under the effect of wind load were analyzed using the finite element method.The static analysis results indicate that the maximum deformation and the maximum stress vary a little with wind-force when the wind-force is smaller than grade 3,but they increase significantly with wind-force when the wind force is larger than the grade 3.Under dynamic wind load,the front 10 order modes and frequencies of the structure are obtained by modal analysis.Under the effect of 8 grade dynamic wind force,the time history responses of the displacement and pulling stress of two important nodes located in the middle of the bridge and at its end are researched,and the stress and displacement distributions of the whole bridge in a moment are also analyzed.Finally,the relationships between the maximum deformation and the maximum stress and the dynamic wind-force are obtained,they are similar to those under static wind load,but when the wind-force is larger than grade 3,the maximum deformation and the maximum stress are almost two times than those under the static wind load.