隨機激勵下鋁蜂窩夾層板非線性特性研究

Nonlinear dynamic analysis of aluminum honeycomb sandwich board based on random excitation

摘要: 為研究鋁蜂窩夾層板的非線性動力學(xué)特性，對鋁蜂窩夾層板做不同激振量級下的隨機振動試驗，并作出非線性幅頻圖。系統(tǒng)的非線性頻響函數(shù)的共振放大倍數(shù)隨著激振量級的增加而減小，其特征與應(yīng)用等效線性化及FPK法計算的帶有非線性阻尼的系統(tǒng)理論得出的結(jié)果相似，擬合結(jié)果也表明試件的等效阻尼系數(shù)隨外激勵變化而變化，故得出文章中的試件帶有非線性阻尼特性。鋁蜂窩夾層板具有非線性阻尼特性這一結(jié)果可對航天器建模提供理論參考依據(jù)。

Abstract: The nonlinear dynamic characteristics of aluminum honeycomb sandwich board, as a widely used compound material in spacecraft, are studied in this paper. With random vibration tests in different test levels, nonlinear frequency response functions (FRF) are obtained; and it is shown that as the excitation level increases, the FRF decreases in magnitude, and the damping ratio increases, which is consistent with the model with nonlinear damping, with FPK transform and equivalent principle method being combined. That reveals the nonlinear damping characteristics in aluminum honeycomb sandwich board. This study provides a theoretical guidance in choosing a model for a nonlinear dynamic system.