【摘要】 本文以二滩拱坝为例,研究了基于QR分解和MAC准则(模态置信度准则)的高拱坝传感器优化布置方法。首先,基于有限元模态分析获取的可测点振型进行了QR分解,以确定传感器的初始位置;其次,通过逐步累积使MAC矩阵最大非对角元最小,以确定最优测点数量及位置;最后,提出了二滩拱坝原型动力测试的传感器优化布置。基于该传感器优化配置结果,开展了二滩拱坝泄洪振动原型动力测试和模态参数识别。结果表明,测点优化后的识别结果不仅能保证识别精度,而且识别出了更高阶次的模态参数。这种方法可为开展泄流条件下高拱坝动力测试与健康诊断的合理测点布置提供理论参考。更多还原

【Abstract】 Taking Ertan Arch Dam as a study case,the optimal layout of sensors for high arch dam is studied herein based on QR decomposition and MAC criterion.Firstly,the QR decomposition is made on the vibration mode of the measurable points obtained on the basis of the finite element modal analysis to determine the initial positions of sensors;secondly,the maximum non-diagonal elements of the MAC matrix are minimized through the gradual accumulation to determine the optimal numbers and positions of the measuring points;finally,the optimal layout of sensors for the prototype dynamic test of Ertan Arch Dam is proposed.Based on the optimized allocation of the sensors,the prototype dynamic test and parameter identification under flood discharge excitation for Ertan Arch Dam are carried out.The result shows that the result of the identification after the optimization concerned can not only ensure the accuracy of the identification,but can identify the modal parameters of more high-orders.This method can provide a theoretical reference for the reasonable layout of the measuring points for both the dynamic test and the safety health diagnosis of high arch dam under flood discharge excitation.更多还原