船舶纵向下水弹性计算方法和结构安全性

The Elastic Calculation of Ship Longitudinal Launch and Structural Safety

为保证船舶下水过程中的结构安全，提出了一种船舶弹性下水计算方法．考虑船体的弹性弯曲、船底结构局部弹性变形、墩木与滑道的弹性压缩，用有限元方法计算任一下水位置时船体的姿态和变形，通过系列计算可预报下水全过程中船体总弯曲力矩、切力及每一对支墩反力的数值与变化，并进而实现船体总强度与局部强度的校核．文中介绍了一个计算实例并对下水安全性进行了讨论．

An elastic calculation of ship launching has been developed for the structural safety of ship during launching operation .The elastic flexibility of ship hull,the local elastic deformation of ship bottom and the compressive elasticity of launching blocks on ship skid way are considered in a finite element analysis of ship hull's bending and its floating state at any skid position.The general bending moment and shear force of ship hull as well as the reaction force at each of support blocks in the whole launching process can be predicated by a series of calculations for defferent skid distances.Then,the general and local strength of ship hull during launching can be checked.An example of launching calculation is presented and the structural safety of ship launching is discussed too.