环境随机激励下在役石油钻机井架试验模态参数识别

针对钻机井架的结构形式和作业特点,详细讨论了模态测试中若干试验参数,如激励方式、传感器位置以及频率分辨率等,提出了基于环境随机激励的钻机井架结构试验模态识别的一种有效方法.根据激振形式,推导了模态参数识别公式,依据结构响应的自功率谱识别井架的模态频率,依据互谱与自谱的峰值之比近似地识别模态振型.针对海洋和陆地钻机两种井架形式进行分析.该方法处理简单、快速、实用,适用于大型复杂钢构结构,具有一定的工程应用价值.

Experimental Modal Parameters Identification of Oil-drilling Derrick under Ambient Random Excitation

Aiming at the design feature and the operating mode of drilling derrick, a number of modal test parameters is discussed in detail such as type and placement of excitations, arrangement of accelerometers, frequency resolution etc. And a effective method used to experimental modal parameters identification under ambient excitation is proposed. Modal frequencies are identified based on auto-spectrum of the structural response, and mode shape is identified in accordance with the ratio of the cross-spectral peak...