基于高阶局部模态的弹性地基上框架结构物理参数识别研究

Research on physical parameter identification of concrete frame structure on elastic foundation based on higher modes

利用框架结构的整体振动模态信息进行局部损伤的判别具有明显的局限性。高阶模态逐渐被人们认识并用来进行局部物理参数识别并用来进行损伤判别。本文以弹性地基上独立基础的框架结构底层柱为研究对象,利用增加的质量块对柱子进行局部损伤的制造,利用脉冲锤击法和激振器扫频实验进行高阶模态对比测试,利用PolyMAX模态分析方法进行损伤前后高阶模态的识别,发现了“高灵敏度高阶模态”的存在。最后通过两端约束Euler梁的计算模型,通过高阶模态来识别物理参数以及地基参数,其中物理参数结果具有较好的可靠性。

Using the global modal information of a frame to diagnose local damage has obvious limits. The higher modes were recognized and used to identify the local physical parameters and to diagnose the damage. Based on the research on the column of the first story with isolated footing, the additional mass was used to cause the damage the hammer-impact method and the sweeping frequency by using vibrator were used to measure contrastively. The PolyMAX modal analysis method was used to identify the modal parameters and the ＂high sensitive higher modes＂ were found. Finally, the Euler beam model with two ends constrained were used as the calculating model. The higher modes were used to identify the physical parameters and the foundation parameters and the physical parameters have high reliability.