利用柔度分解技术,提出一种改进的静力方法用于工程结构损伤诊断中。通过在结构静力反应方程中引入柔度分解式,得到求解柔度扰动参数的线性方程组。由该线性方程组首先计算出各单元柔度扰动参数,再根据柔度扰动参数和刚度扰动参数(损伤参数)之间的关系式,即可计算出各单元损伤参数,据此即可评估结构的损伤状况。所提方法避免了已有方法中需要求解非线性方程组的缺点,无论损伤程度大小如何,均不需要进行迭代运算即可获得精度良好的计算结果。以一个桁架结构为例对所提方法进行验证。结果表明:无论损伤程度大小如何,所提方法只需经过一次计算即可获得精度较高的识别结果,避免多次迭代,显示该方法在计算上的优越性。
The static-based damage identification methods have attracted much attention in the civil engineering field in recent years.Using the flexibility disassembly technique,a new static-based method is presented for structural damage identification.The key idea of the developed theory is to decompose structural flexibility change into a matrix representation of the connectivity between degrees of freedom and a diagonal matrix containing the perturbed flexibility parameters.The first significant advantage of the proposed procedure is that it can detect structural damage by directly using the incomplete static test data.The second significant advantage of the method is that it can obtain reliable extent of damage only by simple computation without any iteration,regardless of whether the damage is small or large.A four-storey frame structure is used as a numerical example to exercise this process and measurement noise is also simulated in damage detection.The results show the good efficiency and stability of the proposed method on the identification of damage on more than one element.It has been shown that the proposed procedure may be a promising method in structural damage identification.