摘要
以某海洋平台结构试验模型为研究对象,提出了Krigging模型与多目标遗传算法优化相结合的动力学模型修正方法。将模态频率设为修正目标,利用待修正参数与平台模态频率间的Kriging模型代替平台有限元模型进行修正。针对近似误差可能对修正结果产生干扰的问题,提出了一种基于多目标遗传算法的局部加点优化方法,用于优化代理模型的拟合精度。通过力锤激励下的室内模型试验对上述方法进行了验证,结果表明,Kriging模型能够有效拟合平台结构参数与固有频率间的复杂映射关系,所提出的优化方法能够显著改善Kriging模型精度,可应用于实际工程。
A dynamics model updating method combining the Kriging model with the multi-scale objective genetic algorithm(MOGA) optimization for the experimental model of an offshore platform structure was proposed. The modal frequencies were set as updating targets, and the Kriging model between updating parameters and modal frequencies of the platform was set up and, in replacement of the commonly used finite element model, applied to the model updating. In order to solve the problem that approximate error may cause a disturbance to the updating result, the method of MOGA based on an infill-sampling optimization approach was provided. Model tests of the offshore platform model in the lab based on hammer excitation were employed to prove the effectiveness of the method. The results show that the Kriging model can effectively reveal the complex mapping relations between the updating parameters and modal frequencies, and the infill-sampling criteria provided can significantly improve the precision of the Kriging model, which can be applied in actual engineering.
引文
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