Optimal Design Of The Structural Dynamic Boundary Conditions And Implementation In Engineering

To control the response of engineering structures working in severe vibrating environment it is necessary to predict and analyze the dynamic behavior of the structures accurately and to design the structures dynamically. In the environment vibration experiment, the encountered engineering problem is that the test clamp which supports the structure should reflect or simulate the dynamic characteristics provided by real boundary conditions of the structure, which is a dynamic design or dynamic simulation of structural boundary. For these situations, a time domain method of the identification of boundary conditions, approaches for dynamic design of structural boundary are developed and investigated in this dissertation. The author also emphasizes on implementation method in engineering of the dynamic simulation of structural boundary conditions. Six aspects concerning the identification of structural boundary conditions, the dynamic simulation of structural boundary conditions and optimal realization in engineering are investigated in the thesis systematically.1. Theory and techniques of modeling of the complex structure have been developed and applied successfully to structure analysis. However, the accurate modeling of joints and boundary conditions of a structure may still be considered a quite challenging task. Therefore, identifying the joint parameters and boundary condition parameters using mathematical model and experimental data attracted many researchers and many such techniques have been developed. The most of the methods are based on the modal data. In this dissertation, Using of differential transform method, the original analysis model of vibration system is transformed to a set of algebraic equations in discrete domain, through which the solution techniques of the dynamic equations are constructed and time domain method of identifying dynamic boundary condition parameters of a structure is derived.2. The numerical simulating and experiment research are conducted for the new identification method. In the experiment, a cantilever beam structure with elastic support at one end is elaborately designed, the finite element model of which is corrected by frequency test and then the responses of the beam with and without the elastic support under harmonic excitation are measured by piezoelectric acceleration...