【摘要】 本文提出了一种新的基于自由振动信息的塔架结构塔身主杆法兰拼装节点螺栓脱落损伤发生位置的识别方法,并通过一塔架结构模型的试验验证了该方法的准确性和有效性。文中,通过在塔架结构塔身主杆所有法兰拼装节点法兰盘外侧竖向布置应变传感器,以该处在塔架结构顶端初始冲击激励下自由振动的竖向应变响应作为螺栓脱落的损伤标识量,依据完好结构与有螺栓脱落损伤结构法兰节点竖向应变的差异构建损伤指标向量,并对一钢管塔架结构模型进行了损伤识别的试验。试验结果表明,此方法的损伤指标向量具有对螺栓脱落敏感,与初始激励大小无关,对损伤位置具有较强的局域性的特点,且塔架结构其它结构损伤对塔身主杆法兰节点螺栓脱落位置诊断的损伤指标向量的特征没有影响。更多还原

【Abstract】 The paper presents a new detection method of the bolt looseness damage locations at flange joints of leg members based on the free vibration data,and an experiment of bolt looseness damage locations detection at flange joints is conducted to show its accuracy and validity.In the paper,the free vibration longitudinal strain responses,which are measured by the strain sensors installed at the outside of the flange joints of tower legs under the initial impact excitation applied to the top of the tower are selected as the reasonable damaged feature.And the damage index vector can be defined based on the difference between longitudinal strain of the undamaged and damaged structures.Accordingly,an experiment of a tower structure model is carried out for verification.Experimental results show that the proposed damaged index is efficient for the bolt looseness location detection and sensitive to the damage locations,and also independent of the initial excitation.Moreover,other structural damage to the tower structure has no effect on the damage index vector of the bolt looseness location at flange joint of leg members.更多还原