【作者】 王勇；

【导师】 李盈利； 孙强；

【作者基本信息】 中南大学 ， 工程（专业学位）， 2022， 硕士

【摘要】 城市轨道交通迅速发展,人们对乘车舒适性的要求也随之提高,振动与噪声问题亟待解决。针对星型-内凹六边形超结构的减振性能开展研究,得到低频减振调控规律,并进行优化设计,应用于列车地板减振中。建立16自由度质量弹簧解析模型研究星型蜂窝的弹性波传播和振动衰减机理。带隙边界模态表明带隙机理为单极子、偶极子、四极子和旋转共振等模态的共同作用。根据带隙机理,调整参数打开了第2、3条色散曲线之间的低频带隙,得到带隙调控规律。有限周期结构的谐波响应验证了带隙的存在,且在色散曲线负斜率频率范围内表现出各向异性。建立8自由度内凹六边形蜂窝弹性波传播模型。低频色散曲线发生能量交叠,根据交叉点前后模态将色散曲线分类。有限周期晶格的谐波响应表明,当模态中质量沿同一方向运动时,在其垂直方向上形成方向带隙。利用有限元方法研究了星型蜂窝与内凹六边形蜂窝组成复合蜂窝结构,具有更低频的带隙。有限周期结构的谐波响应表明,部分带隙内的共振峰处在输入端产生共振,可以实现在隔振的同时进行能量收集。利用遗传算法优化复合蜂窝结构,得到具有1000Hz～2000 Hz减振频率的结构参数,通过仿真验证,其能有效衰减实车激励。初步验证了块状与板状减振结构的静力学性能,模态频率均高于20 Hz。制作了复合蜂窝样件开展振动试验,验证其减振性能。图75幅,表8个,参考文献100篇更多还原

【Abstract】 With the rapid development of urban rail transit,people’s requirements for ride comfort have also increased,and the problems of vibration and noise need to be solved urgently.The vibration attenuation performance of the star-concave hexagonal metastructure is studied,and the low-frequency vibration attenuation regulation law is obtained,and the optimized design is applied to the train floor vibration attenuation.A 16-DOF mass-spring analytical model is established to study the elastic wave propagation and vibration attenuation mechanism of star honeycombs.The bandgap boundary modes indicate that the bandgap mechanism is a combination of modes such as monopole,dipole,quadrupole and rotational resonance.According to the band gap mechanism,adjusting the parameters opens the low frequency band gap between the second and third dispersion curves,and obtains the regulation rule of the band gap.The harmonic response of the finite periodic structure verifies the existence of the band gap and exhibits anisotropy in the frequency range of the negative slope of the dispersion curve.An elastic wave propagation model of a concave hexagonal honeycomb with 8 degrees of freedom is established.The energy overlap occurs in the low frequency dispersion curves,and the dispersion curves are classified according to the modes before and after the intersection.The harmonic responses of finite-period lattices show that when the masses in the modes move in the same direction,a directional band gap is formed in their perpendicular directions.The composite honeycomb structure composed of star honeycomb and concave hexagonal honeycomb with lower frequency band gap is studied by finite element method.The harmonic response of the finite periodic structure shows that the resonance peaks in part of the bandgap resonate at the input end,which can realize energy harvesting while isolating vibrations.The composite honeycomb structure is optimized by genetic algorithm,and the structural parameters with vibration damping frequency of 1000 Hz～2000 Hz are obtained.Through simulation verification,it can effectively attenuate the excitation of the real vehicle.The static performance of the block and plate damping structures is preliminarily verified,and the modal frequencies are higher than 20 Hz.A composite honeycomb sample was made to conduct vibration tests to verify its vibration attenuation performance.更多还原