船舶裂纹轴非线性振动特性仿真研究

Nonlinear vibration characteristics simulation of a crack ship shaft

为研究船舶裂纹推进轴的非线性振动特性,本文基于三维有限元单元法建立含有裂纹的船舶推进轴系有限元模型,并研究其模态特性及其单位阶跃非线性振动特性。计算结果表明,由于裂纹的存在,推进轴一阶模态频率将有所下降,并且振型发生较大的变化。在同样脉冲作用下,位移响应峰值将更大,裂纹轴振动频率将有所下降。

In order to study the nonlinear vibration of ship shaft crack characteristics,this paper based on three dimensional finite element element method to establish the finite element model of ship propulsion shafting crack. And its modal characteristics and unit step nonlinear vibration characteristics are then studied. The calculation results show that: because of the existence of the crack shaft,first order modal frequency will be decreased,and major changes have taken place in vibration mode. Under the same pulses,the peak displacement response will be bigger and crack shaft vibration frequency will be decreased.