船舶减振支架是一种具有优良减振性能的隔振装置，使用弹性体将柴油机和齿轮箱等会发生振动行为的设备固定在减振支架上，能够有效防止设备在使用过程中因振动而对船体造成损伤。由于振动疲劳的影响，极易导致船舶减振支架结构在工作过程中突然发生疲劳断裂事故。本文首先对船舶减振支架进行有限元模态和频率响应分析，得到结构应力较大部位。然后，基于功率谱密度（PSD）法和Miner线性累积损伤理论对支架结构未考虑残余应力的振动疲劳寿命进行分析，得到结构易发生振动疲劳破坏的关键部位。最后，根据试验测得的焊接残余应力对S-N曲线进行修正，得到考虑不同焊接残余应力影响的减振支架振动疲劳寿命。研究结果表明：焊接残余应力对支架结构振动疲劳寿命的影响较大，应尽量降低或消除支架结构关键部位的有害焊接残余应力。
Shock absorption support is a kind of vibration-isolated device with excellent vibration-reduced performance. It can effectively prevent damage to the hull caused by vibration during the operation of diesel engine and gearbox on the upper part of the support. Sudden fracture accident of the support would be easily caused during its works due to vibration fatigue. First of all, modal and frequency response are analyzed with the finite element method, and the high stress areas of the support are obtained in this paper. Then, the vibration fatigue life of the support without considering the effect of welding residual stresses is analyzed on the basis of the power spectral density method (PSD) method and Miner linear cumulative damage theory. The key parts which are prone to cause vibration-fatigue damage are obtained. Finally, based on the residual stresses of the support which are measured by the testing, the S-N curves are corrected, and then the vibration fatigue life of the support considering the welding residual stresses is calculated. The results show that the welding residual stresses have a great influence on the vibration fatigue of the support. So it is necessary to minimize or eliminate the harmful welding residual stresses at the key parts of the support.
2018,40(8): 41-44 收稿日期：2018-03-15
DOI：10.3404/j.issn.1672-7649.2018.08.008
分类号：U663.7
基金项目：国家自然科学基金资助项目（51479084）
作者简介：张晓飞(1982-),男,硕士,讲师,研究方向为船体结构与性能
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