Development of Experimental Identification Techniques in Time Domain for Boundary Conditions and Joint Conditions of structures

实验识别领域中最困难的问题之一是确定机器和结构的边界条件和连接条件。为了预测它们的行为，广泛使用诸如有限元法的数值方法。为了得到准确的结果，边界条件和连接条件的准确描述是必不可少的。因此，发展边界条件和节理条件的识别技术具有重要意义。作为第一步，我们在2001年开发了梁的非线性边界条件的技术。该技术基于谐波平衡，因此使用对周期性激励的稳态响应。我们通过数值模拟和实验证实了所提出的技术的适用性。然后，我们推广的技术，使其可以应用到二维问题。作为一个典型的例子，我们开发了一种适用于非轴对称圆板的技术，并通过数值模拟证实了其适用性。然后，作为我们的最终目的，我们在2002年开发了一种使用时间序列数据的技术。与上述技术相比，使用时间序列数据减少了对激励类型以及响应数据的限制。作为一个典型的例子，我们提出了一种技术，适用于梁。通过数值模拟验证了该方法的适用性。

One of the most difficult problems in the field of experimental indentification is to determine the boundary conditions and joint conditions of machines and structures. To predict their behavior, numerical methods such as the finite element method are widely used. To get accurate results, accurate description of the boundary conditions and joint conditions is essential. Thus development of identification techniques of boundary conditions and joint conditions is of great importance.In this study, we aimed to develop general-purpose identification techniques. As a first step, we developed in 2001, a technique for nonlinear boundary conditions of a beam. This technique is based on the harmonic balance, and hence uses steady-state response to a periodic excitation. We confirmed the applicability of the proposed technique by numerical simulation and experiment. Then we generalized the technique so that it can be applied to two-dimensional problems. We developed, as a typical example, a technique applicable to a non-axisymmetric circular plate, and confirmed the applicability by numerical simulation. Then, as our final purpose, we developed in 2002, a technique that uses time series data. Use of time series data reduces limitations on the type of excitations as well as the responses data, as compared with the above technique. As a typical example, we proposed a technique that is applicable to a beam. We confirmed the applicability by numerical simulation.