指数型非粘滞阻尼模型参数识别的理论与试验研究

发布时间：2018-08-25 17:44

【摘要】：振动问题普遍出现在机械、土木和航空领域,我们不但关心振动本身,而且设法通过阻尼耗能来减少振动。目前为止,关于阻尼的研究已经取得了大量的成果,但是关于阻尼物理机制的研究还相当落后。其中一个最主要的原因是与质量和刚度相比,阻尼还无法用一个十分确切的物理量来描述。新近发展起来的指数型非粘滞阻尼模型被认为是更为一般化的阻尼模型,它充分考虑了阻尼力的时滞效应,对它的深入研究是有价值的。对此,本文将阻尼矩阵分解方法拓展到指数型非粘滞阻尼模型中,识别该模型的阻尼系数矩阵;同时,以拟牛顿法中最有效的BFGS(Broyden-Fletcher-Goldfarb-Shanno)方法为理论基础,提出了新的松弛因子迭代计算方法。最后通过一个附加粘弹性阻尼器的单跨双榀二层钢框架的振动台试验,验证了新的阻尼系数矩阵识别方法和松弛因子迭代算法的正确性。具体内容如下:考虑到通过实际现场数据提取模态参数的不完备性,在阻尼矩阵分解方法的基础上,拓展得到一种新的适用于指数型非粘滞阻尼模型的阻尼系数矩阵识别方法。该方法能够考虑指数型阻尼系数矩阵的元素分布形态,可以利用有限的低阶实测模态,较为准确地识别出系统的阻尼系数矩阵。进一步考虑到目前国内外对于指数型非粘滞阻尼模型松弛因子的研究不足以指数型比例阻尼模型为基础,通过拟牛顿法中的BFGS方法提出了新的松弛因子迭代算法。最后对一个相似比为1:4的附加粘弹性阻尼器的单跨双榀二层钢框架模型进行振动台试验,计算确定了整体钢框架模型的非粘滞性参数。通过本文提出的阻尼系数矩阵分解方法和松弛因子迭代算法,识别了该框架的阻尼系数矩阵和松弛因子,进一步考察了本文提出的识别方法在实际运用中的可行性和正确性。
[Abstract]:Vibration problems are common in the fields of machinery, civil engineering and aviation. We not only care about the vibration itself, but also try to reduce the vibration by damping energy dissipation. Up to now, a lot of achievements have been made in the research of damping, but the research on the physical mechanism of damping is still quite backward. One of the most important reasons is that damping can not be described by a very exact physical quantity compared with mass and stiffness. Recently developed exponential non-viscous damping model is considered to be a more general damping model which fully considers the delay effect of damping force and is valuable for further study. In this paper, the damping matrix decomposition method is extended to the exponential non-viscous damping model to identify the damping coefficient matrix of the model, and the most effective BFGS (Broyden-Fletcher-Goldfarb-Shanno) method in the quasi-Newton method is used as the theoretical basis. A new iterative calculation method of relaxation factor is proposed. Finally, the validity of the new damping coefficient matrix identification method and relaxation factor iterative algorithm is verified by a shaking table test of a single-span and two-story steel frame with viscoelastic dampers. The main contents are as follows: considering the incompleteness of extracting modal parameters from actual field data, a new method of identifying damping coefficient matrix for exponential non-viscous damping model is developed on the basis of damping matrix decomposition method. This method can consider the element distribution of the exponential damping coefficient matrix and can accurately identify the damping coefficient matrix of the system by using the finite low-order measured modes. Considering that the research on relaxation factor of exponential non-viscous damping model at home and abroad is not sufficient for exponential proportional damping model, a new relaxation factor iteration algorithm is proposed by using BFGS method in quasi-Newton method. Finally, a shaking table test of a single-span and two-story steel frame model with a similar ratio of 1:4 and visco-elastic dampers is carried out, and the non-viscous parameters of the integral steel frame model are calculated and determined. The damping coefficient matrix and relaxation factor of the frame are identified by the damping coefficient matrix decomposition method and relaxation factor iterative algorithm proposed in this paper. The feasibility and correctness of the proposed identification method in practical application are further investigated.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB535

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