To overcome the difficulties in measuring rotational dynamic flexibility and exerting moment excitation on the substructure which lie in the experimental component mode synthesis method, a numerical differentiation formula was utilized to estimate the rotational displacement, the moment excitation was represented by a parallel force system, and then a new indirect technique for measuring the rotational dynamic flexibility was developed. By measuring a set of force induced translational dynamic flexibilities at a limited number of points using hammer excitation or frequency sweeping method, it is possible to express approximately the moment induced rotational dynamic flexibilities in terms of those measured quantities. The merits of this indirect measuring technique are that no attached T block no moment excitation, and even no parallel force excitations are needed. The indirect measurement of rotational dynamic flexibility was then brought into the fixed frequency residual dynamic flexibility based experimental component mode synthesis method to satisfy the rotational compatibility at the interface of substructures. Numerical examples demonstrate the validity and efficiency of the proposed method.%将谐波集中力矩等效为谐波集中力系,用转角的数值微分公式构造一种全新的转角动柔度间接测量技术,克服实验模态综合法中转角难测量与集中力矩难加载的困难.该间接测量技术无需附加任何质量块与施加集中力矩及集中力系,只需几次锤击实验或扫频实验,即可将集中力矩作用下的转角动柔度用集中力作用下的平动动柔度线性表示.将转角动柔度的间接测量技术应用于基于定频剩余动柔度的实验模态综合法中,数值实验表明,该转角动柔度间接测量技术切实可行,能有效解决实验模态综合法中界面自由度不匹配问题,可提高实验模态综合法精度及可靠性.
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