基于改进谱分析法的船舶疲劳强度直接计算

Direct calculation of ship fatigue strength based on improved spectral analysis method

针对目前船舶疲劳强度评估问题,频域谱分析法将应力范围服从Rayleigh窄带分布,造成结果偏保守。而时域法则计算时间过长,无法满足快速预估需求。本文以频域谱分析法为基础,提出一种适用于宽带随机过程的改进谱分析法,并以实船为算例进行计算分析。结果表明,基于改进谱分析法的疲劳计算结果与精确解差距较小,可以提供一个相对可靠的船舶疲劳损伤结果。新方法对解决宽带随机过程下的船舶疲劳评估问题有一定参考意义。

Aiming at the problem that the assessment of fatigue strength,the results are conservative based on spectral analysis method.Because the range of stress is treated as Rayleigh’s model,Rayleigh’s model is a narrow model.The time of calculation based on time-domain analysis method is too long,this method is unable to meet the requirement of the fast assessment.This paper gives improved spectral analysis method of fatigue assessment suitable for wide-band random process based on spectral analysis method.Then Taking a ship as an example to analyze.The results show that:the result of calculation based on improved spectral analysis method is close to the accurate solution.This method can provide a relatively reliable result of assessment for fatigue strength.The new method has reference significance for assessment of fatigue strength under wide-band random process.