基于模态应变能密度理论的网架结构损伤识别方法

为了研究网架结构的损伤检测方法,根据应变能密度理论,提出采用单元模态应变能密度差值作为网架结构损伤识别指标的方法,以损伤单元模态应变能密度差值的大小初步确定单元的损伤程度。分析了5种具有代表性的损伤工况,并在数值计算结果中引入了白噪声。结果显示,在一阶模态下,针对单损伤、多损伤和轻微损伤、严重损伤等不同损伤工况,损伤杆件的模态应变能密度差值均为高值。因此,该方法可以有效识别出网架结构的损伤位置,根据损伤单元的模态应变能密度差值大小初步确定单元的损伤程度,且在一定的噪声水平下具有较强的鲁棒性,对网架结构损伤识别具有参考价值。

Identification of grid structure damage based on the theory of modal strain energy density

In order to study the method of detecting grid structure damage, this paper proposes to use elemental modal strain energy density difference as an index of identifying grid structure damage according to the theory of strain energy density, thus preliminarily determining the degree of elemental damage. A numerical analysis is performed on five typical working conditions of damage, and white noise is introduced in numerical computation. The results show that for different working conditions of damage, including single damage, multiple damage, slight damage and severe damage, the modal strain energy density differences of the damaged member in the first-order mode remain high. Therefore, this method can effectively identify the damaged location of the grid structure and preliminarily determine the degree of element damage according to the size of the modal strain energy density difference. Furthermore, it exhibits strong robustness at a certain noise level and provides a reference for the identification of grid structure damage.