导管架式海洋平台模型的模态试验与计算

MODAL TEST AND CALCULATION OF JACKT'S OFFSHORE PLATFORM MODEL

本文给出导管架式海洋平台模型在五种不同介质中模态参数的识别结果,观测了水及回填砂对模型的固有频率、阻尼比和振型等模态参数的影响及其变化规律,试验了甲板质量及其质心偏移对模态参数的影响,发现丁模型构件节点开裂导致甲板振型变化远大于模型固有频率的下降。有限元计算结果与试验结果的一致性表明,依据试验结果不断地修改计算数学模型是建模修模的有效途径。

A testing of offshore platform model made of polyearbonate has been made in labora- tory.The identified and Computed modal parameters of jacket's offshore platform are presented for five different medium in this paper.The effect of water and sand on natural frequencies,damping factors and mode shapes of offshore platform model has already measured.The effect of mass of deck and eccentricity of mass on modal para- meters was observed.Analytical and experimental results show that natural frequency changes a few percent only and normalized mode shape of deck changes more than20% when a joint is damaged,The modal parameters have been computed by finite element method.Calculating values of model parameters accord with testing values.The fact shows that mathematical model of the offshore platform model is correct.