低速运动船只撞击埋置框架结构动力分析模型

Dynamic analysis model of partly buried framed structure subjected to impact of low-velocity moving ship

通过引入合理的撞击模型,建立了水面运动船只低速撞击埋置框架结构的传递矩阵-节点耦合矩阵动力分析模型。该模型可模拟船只与结构在撞击过程中的短暂脱离,并分析撞击力时程曲线和整个撞击系统的动力响应。与有限元方法的比较验证了结构传递矩阵-节点耦合矩阵动力分析方法的有效性。不同于规范计算方法,分析发现撞击过程中的最大撞击力不仅与船只的初始动能有关,还受船只与结构间的接触刚度及结构的自身刚度影响,这两种刚度越大,则最大撞击力也越大,撞击持续时间则越短,而撞击力时程曲线的振荡越明显,甚至在船只撞击结构后的很短时间内就可能产生较大的撞击力峰值。

Based on a proposed reasonable impact model, an impact analysis method of transfer matrices and joint coupling matrices is presented for the partly buried framed structure subjected to the low-velocity impact of a moving ship. A spring between the ship and the structure is taken into account, and the moment separation between the moving ship and the structure during the collision can be predicted. Excellent agreement with the traditional finite element method verifies the method of transfer matrices and joint coupling matrices for the dynamic response analysis of the framed structure. Different to the relative China code and US code, the present analysis finds that the maximal impact force during the collision depends on not only the mass and the initial velocity of the moving ship, but also the contact stiffness between the ship and the structure as well as the stiffness of the structure. With the increase of both the stiffness, the maximal impact force during the collision increases, the duration time of the collision decreases, and the time history of the impact force fluctuates increasingly. If both the stiffness is large, there will be a large peak value of the impact force at a moment after the beginning of the collision.