桥墩柔性防撞装置的静态等效弹性系数

Effective Stiffness of a Crashworthy Device for Ship-pile Collision Cushion

给出了一个分析桥墩柔性防撞装置等效弹性系数的简单模型,该模型由分布的辐射弹簧以及弹簧连接的2个同心刚体圆环构成.研究表明:无量纲化平动反力是无量纲化平动位移的单值函数,包括初始线性段、非线性段、以及软化段.初始等效弹性系数相当于全体弹性单元并联弹性系数的1/2;非线性响应由压缩弹簧的大变形(几何非线性)产生,在位移达到半径差的93.8%时,反力达到峰值.此外,也得出了纯转动时扭矩与转角之间关系,以及平动-转动同时发生时的压-扭耦合弹性系数.并用有限元方法分析了外钢围弹性变形对系统弹性系数的影响.

This paper presents a model for calculating the effective quasi-static stiffness of a new flexible device designed for ship-pile collision defense.The model consists of two concentric rigid rings linked by distributed spoke spring elements.Analytical investigations of the model give the translational and rotational stiffness of it,as well as the coupling between the two deformation modes.The nondimensional translational ＂reaction force-displacement＂ curve includes an initial linear phase,a nonlinear hardening phase,and a nonlinear softening phase.The initial elastic coefficient of the structure is equivalent to that calculated when half of the springs are connected in parallel.Maximum translational reaction force of the structure is achieved at relative deformation of 0.938.The nondimensional ＂torque-twist＂ relationship is given,and a quantitative evaluation of the translation-twist coupling effects is conducted.Using a FEM model the influence of outer ring deformation on the elastic property of the structure is investigated.It is seen that the deformation of the outer ring brings extra flexibility to the whole structure.