Variable stiffness composite laminates(VSCLs)are promising in aerospace engineering due to their designable material properties through changing fiber angles and stacking sequences.Aiming to control the thermal postbu...Variable stiffness composite laminates(VSCLs)are promising in aerospace engineering due to their designable material properties through changing fiber angles and stacking sequences.Aiming to control the thermal postbuckling and nonlinear panel flutter motions of VSCLs,a full-order numerical model is developed based on the linear quadratic regulator(LQR)algorithm in control theory,the classical laminate plate theory(CLPT)considering von Kármán geometrical nonlinearity,and the first-order Piston theory.The critical buckling temperature and the critical aerodynamic pressure of VSCLs are parametrically investigated.The location and shape of piezoelectric actuators for optimal control of the dynamic responses of VSCLs are determined through comparing the norms of feedback control gain(NFCG).Numerical simulations show that the temperature field has a great effect on aeroelastic tailoring of VSCLs;the curvilinear fiber path of VSCLs can significantly affect the optimal location and shape of piezoelectric actuator for flutter suppression;the unstable panel flutter and the thermal postbuckling deflection can be suppressed effectively through optimal design of piezoelectric patches.展开更多
针对间隙非线性机翼颤振系统的亚临界问题,引入了非线性能量阱(nonlinear energy sink,NES)技术来提高系统发生极限环振荡的临界速度。建立了具有NES控制的间隙非线性机翼颤振系统动力学模型,并分析了质量比、频率比、阻尼比、相对位置...针对间隙非线性机翼颤振系统的亚临界问题,引入了非线性能量阱(nonlinear energy sink,NES)技术来提高系统发生极限环振荡的临界速度。建立了具有NES控制的间隙非线性机翼颤振系统动力学模型,并分析了质量比、频率比、阻尼比、相对位置等NES参数对颤振系统极限环振荡的抑制效果,以及NES参数对颤振系统极限环振荡临界速度的影响规律。结果表明,阻尼比越大,可以在越小的自振频率比情况下使系统进入稳定区,但需要更苛刻的NES位置要求,即越靠近机翼前缘;而阻尼比越小,则使颤振系统极限环振荡响应进入稳定区所需的NES质量越小。在NES位置靠近机翼前缘时,增大自振频率比会使极限环振荡抑制效果有明显的提升,而增大质量比可以显著提高极限环振荡的抑制效果和临界速度。此外,NES的阻尼比越小,其颤振系统的极限环振荡抑制效果越好。展开更多
基金Project(JCYJ20190808175801656)supported by the Science and Technology Innovation Commission of Shenzhen,ChinaProject(2021M691427)supported by Postdoctoral Science Foundation of ChinaProject(9680086)supported by the City University of Hong Kong,China。
文摘Variable stiffness composite laminates(VSCLs)are promising in aerospace engineering due to their designable material properties through changing fiber angles and stacking sequences.Aiming to control the thermal postbuckling and nonlinear panel flutter motions of VSCLs,a full-order numerical model is developed based on the linear quadratic regulator(LQR)algorithm in control theory,the classical laminate plate theory(CLPT)considering von Kármán geometrical nonlinearity,and the first-order Piston theory.The critical buckling temperature and the critical aerodynamic pressure of VSCLs are parametrically investigated.The location and shape of piezoelectric actuators for optimal control of the dynamic responses of VSCLs are determined through comparing the norms of feedback control gain(NFCG).Numerical simulations show that the temperature field has a great effect on aeroelastic tailoring of VSCLs;the curvilinear fiber path of VSCLs can significantly affect the optimal location and shape of piezoelectric actuator for flutter suppression;the unstable panel flutter and the thermal postbuckling deflection can be suppressed effectively through optimal design of piezoelectric patches.
文摘针对间隙非线性机翼颤振系统的亚临界问题,引入了非线性能量阱(nonlinear energy sink,NES)技术来提高系统发生极限环振荡的临界速度。建立了具有NES控制的间隙非线性机翼颤振系统动力学模型,并分析了质量比、频率比、阻尼比、相对位置等NES参数对颤振系统极限环振荡的抑制效果,以及NES参数对颤振系统极限环振荡临界速度的影响规律。结果表明,阻尼比越大,可以在越小的自振频率比情况下使系统进入稳定区,但需要更苛刻的NES位置要求,即越靠近机翼前缘;而阻尼比越小,则使颤振系统极限环振荡响应进入稳定区所需的NES质量越小。在NES位置靠近机翼前缘时,增大自振频率比会使极限环振荡抑制效果有明显的提升,而增大质量比可以显著提高极限环振荡的抑制效果和临界速度。此外,NES的阻尼比越小,其颤振系统的极限环振荡抑制效果越好。
