【摘 要】
：
A novel elastic sandwich metamaterial plate with composite periodic rod core is designed,and the frequency band-gap characteristics are numerically and experimentally inves-tigated.The finite element and spectral element hybrid method(FE-SEHM)is developed
【机 构】
：
College of Aerospace and Civil Engineering,Harbin Engineering University,Harbin 150001,China;Institu
论文部分内容阅读
A novel elastic sandwich metamaterial plate with composite periodic rod core is designed,and the frequency band-gap characteristics are numerically and experimentally inves-tigated.The finite element and spectral element hybrid method(FE-SEHM)is developed to obtain the dynamic stiffness matrix of the sandwich metamaterial plate.The frequency response curves of the plate structure under the harmonic excitation are calculated using the presented numerical method and validated by the vibration experiment.By comparing with the frequency response curves of sandwich metamaterial plate with pure elastic rod core,improved band-gap properties are achieved from the designed metamaterial plate with composite periodic rod core.The elastic metamaterial plate with composite periodic rod core can generate more band-gaps,so it can suppress the vibration and elastic wave propagation in the structure more effectively.
其他文献
Crushing characteristics of single particles are the basis of granular material simula-tion with discrete element method(DEM).To improve the universality and precision of crushable DEM model,inhomogeneous stiffness and strength properties are introduced i
In-plane compression experiments are performed on 3D fine weave pierced C/C composite at a wide strain rate range of 0.0001/s-1000/s.The in-plane compressive failure mech-anism of the composite at quasi-static and high strain rates is analyzed by a scanni
目的:以甘肃省某高校教师群体为研究对象,采用不同诊断标准评价高校教师体重超重及肥胖流行情况,为进一步健康干预采集数据.方法:以甘肃省某高校教师为研究对象,于2018年4-7月采用随机抽样法,测定体脂率(BF)、体质指数(BMI)和腰围(WC),分别判断超重和肥胖.结果:共获得有效标本336名,以BMI、BF为标准,超重检出率分别为33.04％、62.5％,男教师超重率为47.59％、62.65％,女教师超重率为18.82％、62.35％,以BMI为标准超重检出率低于BF标准,差异有统计学意义;以BMI、B
The observations of microorganisms revealed how they swim.As inspired by them,studies on artificial micro-robots with various actuation mechanisms have been thriving.To elucidate the essential concepts in understanding the dynamic behaviors of natural and
We present a new test method for the accurate measurement of the transverse tensile interfacial strength of rare-earth barium copper oxide(REBCO)-coated conductor(CC)tapes to overcome heavy scattering of data tested using regular test methods.A new compos
The hydrogen effect on the nucleation and motion of dislocations in single-crystal bcc Fe with(110)surface was investigated by both nanoindentation experiments and discrete dislocation dynamics(DDD)simulation.The results of nanoindentation experiments sho
通过Midas Civil有限元软件建立拱圈模型和拱圈-拱上结构联合作用模型,对空腹式无铰拱桥进行仿真模拟,引入联合作用系数K,运用系数k对比分析两种结构状态下的计算结果.联合作用下填料有利于拱板应力分布更趋于合理化;横桥向联合作用系数趋势基本一致,但反映出填料约束作用中间优于边缘效果,改善主拱结构的受压状态,降低了拱的挠度约10％,从而提高了拱圈稳定性.联合作用模型可全面真实地反映主拱的实际受力状态.拱上填料的存在分散集中荷载,保证均匀传递,使拱圈的内力得到削弱;现行规范却忽视了拱上结构与拱圈共同作用对
目的:对比不同方案在Hp阳性慢性胃炎患者中的应用价值.方法:90例Hp阳性慢性胃炎患者随机分组,对照组予奥美拉唑、磷酸铝凝胶、羟氨苄青霉素与克拉霉素,观察组予埃索美拉唑、胶体果胶铋胶囊、阿莫西林与呋喃唑酮,两组均持续给药4周后评估疗效.结果:观察组总有效率(97％VS85％)、幽门螺杆菌(Hp)根除率(93％VS78％)高于对照组(P<0.05).症状缓解时间(2.13±0.58天VS3.54±0.65天)和住院时间(4.11±1.05天VS6.33±1.23天)短于对照组(P0.05).结论:含铋剂方案
In this paper,a semi-discrete model based on peridynamics(PD)for engineered cementitious composites(ECCs)is applied to simulate the fracture behavior of functionally graded ECC(FGECC)beams.This is a new application of PD in ECC.Prior to simulating the cra
In this work,two typical interfaces are established for the antisymmetric plate wave by introducing linear defect in between phononic crystals with opposite valley Hall phases.The evolution of projected curves is demonstrated as the defect width increases