考虑温度梯度的模态应变能法海洋平台损伤检测研究

Damage detection for an offshore platform based on modal strain energy method considering temperature gradient

针对导管架式海洋平台,研究了海水温度梯度对结构整体损伤检测方法之一的模态应变能法的影响。以一个导管架平台为模型,考虑温度对钢材弹性模量的影响,建立了该平台在模拟的海水温度梯度下的有限元模型。通过使用模态应变能法对该模型进行损伤检测,总结了温度梯度对基于模态应变能法的海洋平台损伤检测的影响规律。结果表明温度梯度会使该方法损伤定位能力变弱,对结构冗余度越大的构件影响越大;同时会使损伤程度识别精度降低,构件结构冗余度越大、损伤程度越小,影响越大。

For offshore jacket platforms,influences of seawater temperature gradient on modal strain energy method,one of the methods for structural global damage detection,were studied.Taking a jacket-type offshore platform as a model,its finite element model under a simulated seawater temperature gradient was built regarding influences of temperature on steel elastic modulus.By detecting and analyzing the damage simulated on this model using modal strain energy method,the influence rules of temperature gradient on damage detection for the offshore platform based on modal strain energy method were summarized.It was demonstrated that the temperature gradient weakens the damage location ability of the method,especially for the members with greater structural redundancy,and it also reduces the accuracy of damage extent detection,the influence of the temperature gradient is greater on the members with greater structural redundancy and lower damage extent.