壳体动响应阻尼系数的ALE数值反演研究

ALE Numerical Inversion Research on Damping Coefficients of Shell's Dynamic Response

圆柱壳体作为航空航天工程中的主要结构构形,对其在空气中运动的阻尼特性进行研究具有重要意义。首先运用有限元软件LS-DYNA的任意拉格朗日欧拉算法(Arbitrary Lagrangian-Eulerian,简称ALE)模块对不同几何尺寸的圆柱壳体在空气中的运动历程进行动响应计算分析,并通过不同尺度大小空气域对数值计算的准确性进行验证;然后采用粘性阻尼模型模拟空气作用,用Isight优化软件进行最佳逼近,反演出与空气对圆柱壳体作用等效的质量阻尼系数和刚度阻尼系数,并应用于加筋模型和缩小尺寸模型进行验算。结果表明:用反演系数计算的结果和ALE结果吻合良好,质量和刚度的改变对阻尼系数没有明显影响。

Cylindrical shell plays an important role in aerospace engineering, and it is of great significance to re- search on damping characteristics during its motion in the air. Firstly the dynamic responses of cylindrical shells are analyzed using the Arbitrary Lagrangian-Eulerian（ALE） finite element method in LS-DYNA software, and the validity of the model is verified. Then the equivalent damping coefficients of the system are obtained using inversion method by the Isight software, which are verified by comparing with corresponding models. The re- suits indicate that the inversion damping coefficients can be used to replace the ALE method in simulating cylin- drical shell＇s motion in the air, while the stiffness and mass are of little effect on damping coefficients.