基于动力特性的木地板损伤检测

Damage Detection of Simply Supported Beam Based on Dynamic Response

由于役木地板结构在使用过程中会发生局部开裂等损伤从而对木地板结构的安全产生不利影响,因此对木地板结构进行健康监测十分重要,而识别木地板的损伤位置与损伤程度则是结构监测的关键。为实现木地板结构损伤的定位与定量,将木地板结构简化成简支梁,从梁的受迫振动方程出发,利用振型叠加法计算损伤前后简支梁在简谐激励下的响应,以单元刚度的降低来模拟梁的局部损伤,通过引入损伤系数矩阵,利用结构损伤前后的固有频率和未损伤结构的振型数据计算刚度影响系数,进行损伤位置与损伤程度的判定,克服了频率作为全局量在损伤识别应用上的不足。数值模拟结果表明,该方法能够快速准确地识别出木地板结构的单一位置和多个位置的局部损伤,并且对模拟测量噪声不敏感,因此该方法为木地板结构损伤识别提供了一条可靠的途径。

Assume there are different damage positions and extents in wood floor structure, and put the wood floor structure as simply supported beam. Vibration model addition method was used for the forced vibration analysis of wood floor structures. Natural frequencies of structures before and after damage and vibration mode data of undamaged beam were used to calculate the stiffness influence coefficients which be used to detect the location and the level of the local damage（s）. It is found that the local damage（s） can be identified successfully from the stiffness influence coefficients. These results have important significance in detecting and recognizing the structural damage of wood floor structures.