用Poly MAX方法进行弹性地基板的实验模态分析

对弹性地基上自由板进行了脉冲锤击法模态试验研究。针对传统模态识别方法难以准确识别重频、高阻尼结构的模态参数的特点，利用LMSTest．Lab软件中Poly MAX方法对地基板的传递函数进行模态参数估计和识别。实测及分析表明实际地基上的自由板不存在纯刚体模态。利用识别的模态频率分别对Winkler地基，双参数地基的地基参数进行了识别。利用蒙特卡罗模拟计算地基参数以标准差5％变化时的频率值，发现地基的不均对弹性地基板的频率值有着重要的影响。为道路工程和岩土工程中混凝土板的地基参数识别和损伤诊断提供了手段和方法。

EXPERIMENTAL MODAL ANALYSIS OF A SLAB ON ELASTIC FOUNDATION BY POLYMAX METHOD

The modal test of an edge-free slab on elastic foundation is done by hammer impulse method.The traditional methods which are difficult to identify modal parameters of structures with overlap modal frequencies and high modal damping are not used here.On the contrary,the PolyMAX method of the software LMS Test.Lab is used to estimate and identify modal parameters in the transfer functions of the slab.Measuring and analyzing indicate that there are no rigid body modes in the edge-free slab on the actual foundation.The identified modal frequencies are used to identify parameters of the Winkler foundation and the two-parameter foundation.The Monte Carlo simulation process is conducted during the foundation parameters varying with 5% standard deviation.It is found that the non-uniformity of the foundation has significant influence on the modal frequencies of the slab on elastic foundation.The proposed technique is applicable for foundation parameter identification and damage diagnosis of concrete slabs used in road and geotechnical engineering.