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Bionic lightweight design of limb leg units for hydraulic quadruped robots by additive manufacturing and topology optimization

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Bio-Design and Manufacturing 2024年第1期7卷 1-13页

作者： Huaizhi Zong Junhui Zhang Lei Jiang Kun Zhang Jun Shen Zhenyu Lu Ke Wang Yanli Wang Bing Xu The State Key laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310058China Unmanned Vehicle research and Development Center China North Vehicle Research InstituteBeijing 100072China School of Mechatronic Engineering Nanchang UniversityNanchang 330031China Auclean high-Tech Ltd. Wuxi 214108China

Galloping cheetahs,climbing mountain goats,and load hauling horses all show desirable locomotion capability,which motivates the development of quadruped *** various quadruped robots,hydraulically driven quadruped robots show great potential in unstructured environments due to their discrete landing positions and large *** the most critical movement unit of a quadruped robot,the limb leg unit(LLU)directly affects movement speed and reliability,and requires a compact and lightweight *** by the dexterous skeleton–muscle systems of cheetahs and humans,this paper proposes a highly integrated bionic actuator system for a better dynamic performance of an *** propose that a cylinder barrel with multiple element interfaces and internal smooth channels is realized using metal additive manufacturing,and hybrid lattice structures are introduced into the lightweight design of the piston *** addition,additive manufacturing and topology optimization are incorporated to reduce the redundant material of the structural parts of the *** mechanical properties of the actuator system are verified by numerical simulation and experiments,and the power density of the actuators is far greater than that of cheetah *** mass of the optimized LLU is reduced by 24.5%,and the optimized LLU shows better response time performance when given a step signal,and presents a good trajectory tracking ability with the increase in motion frequency.

关键词： Additive manufacturing Bionic lightweight design Limb leg unit Quadruped robot Trajectory tracking

Energy dissipation mechanism and ballistic characteristic optimization in foam sandwich panels against spherical projectile impact

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Defence Technology（防务技术） 2024年第5期35卷 108-122页

作者： Jianqiang Deng Tao Liu Liming Chen Xin Pan Jingzhe Wang Shaowei Zhu Weiguo Li College of Aerospace Engineering Chongqing UniversityChongqing 400030China State Key laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing 400030China Chongqing Key laboratory of Heterogeneous material Mechanics Chongqing UniversityChongqing 400030China State Key laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

This study systematically examines the energy dissipation mechanisms and ballistic characteristics of foam sandwich panels(FSP)under high-velocity impact using the explicit non-linear finite element *** on the geometric topology of the FSP system,three FSP configurations with the same areal density are derived,namely multi-layer,gradient core and asymmetric face sheet,and three key structural parameters are identified:core thickness(t_(c)),face sheet thickness(t_(f))and overlap face/core number(n_(o)).The ballistic performance of the FSP system is comprehensively evaluated in terms of the ballistic limit velocity(BLV),deformation modes,energy dissipation mechanism,and specific penetration energy(SPE).The results show that the FSP system exhibits a significant configuration dependence,whose ballistic performance ranking is:asymmetric face sheet>gradient core>*** mass distribution of the top and bottom face sheets plays a critical role in the ballistic resistance of the FSP *** BLV and SPE increase with tf,while the raising tcor noleads to an increase in BLV but a decrease in ***,a face-core synchronous enhancement mechanism is discovered by the energy dissipation analysis,based on which the ballistic optimization procedure is also conducted and a design chart is *** study shed light on the anti-penetration mechanism of the FSP system and might provide a theoretical basis for its engineering application.

关键词： Sandwich panel numerical simulation Ballistic resistance Specific penetration energy Energy analysis

Novel Soft Magnetic Co-Based Ternary Co-Er-B Bulk metallic Glasses

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Acta Metallurgica Sinica(English Letters) 2024年第9期37卷 1633-1642页

作者： Jie Lu Yanhui Li Shuang Ma Wanping Li Feng Bao Zhengwang Zhu Qiaoshi Zeng Haifeng Zhang Man Yao Wei Zhang Key laboratory of materials Modification By Laser Ionand Electron Beams(Ministry of Education)School of Materials Science and EngineeringDalian University of TechnologyDalian116024China School of Metallurgy Northeastern UniversityShenyang110819China Center for high Pressure Science and Technology Advanced research(HPSTAR) PudongShanghai201203China

In this work,a series of Co-based ternary Co-Er-B bulk metallic glasses(BMGs)with excellent soft magnetic properties and high strength were developed,and the local atomic structure of a typical Co_(71.5)Er_(3.5)B_(25) metallic glass was studied through in situ high-energy synchrotron X-ray diffraction and ab initio molecular dynamics *** results reveal that the BMG samples can be obtained in a composition region of Co_(68.5-71.5)Er_(3.5-4)B_(25-27.5) by a conventional copper-mold casting *** Co-Er-B metallic glasses possess stronger atomic bond strengths and denser local atomic packing structure composed of a higher fraction of icosahedral-like clusters but fewer deformed body-centered cubic and crystal-like polyhedrons,and they exhibit slower atomic diffusion behaviors during solidification,as compared to Co-Y-B *** enhancement in structural stability and the retardation of atomic-ordered diffusion lead to the better glass-forming ability of the Co-Er-B *** smaller magnetic anisotropy energy in the Co-Er-B metallic glasses results in a lower coercivity of less than 1.3 A/*** Co-Er-B BMGs exhibit high-yield strength of 3560-3969 MPa along with distinct plasticity of around 0.50%.

关键词： Co-based bulk metallic glass Glass-forming ability Soft magnetic property Ab initio molecular dynamics simulation Local atomic structure

high-Order Two-Scale Asymptotic Paradigm for the Elastodynamic Homogenization of Periodic Composites

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Acta Mechanica Solida Sinica 2024年第1期37卷 124-138页

作者： Wei-Zhi Luo Mu He Liang Xia Qi-Chang He State Key laboratory of Intelligent Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China Laboratoire Modélisation et simulation Multi-Echelle MSME UMR 8208 CNRSUniversite Gustave Eiffel77454 Marne-la-ValléeFrance

The classical two-scale asymptotic paradigm provides macroscopic and microscopic analyses for the elastodynamic homogenization of periodic composites based on the spatial or/and temporal variable,which offers an approximate framework for the asymptotic homogenization analysis of the motion ***,in this framework,the growing complexity of the homogenization formulation gradually becomes an obstacle as the asymptotic order *** such a context,a compact,fast,and accurate asymptotic paradigm is *** work reviews the high-order spatial two-scale asymptotic paradigm with the effective displacement field representation and optimizes the implementation by symmetrizing the tensor to be ***,the modified implementation gets rid of the excessive memory consumption required for computing the high-order tensor,which is demonstrated by representative one-and two-dimensional *** numerical results show that(1)the contrast of the material parameters between media in composites directly affects the convergence rate of the asymptotic results for the homogenization of periodic composites,(2)the convergence error of the asymptotic results mainly comes from the truncation error of the modified asymptotic homogenized motion equation,and(3)the excessive norm of the normalized wavenumber vector in the two-dimensional inclusion case may lead to a non-convergence of the asymptotic results.

关键词： Composites Homogenization Asymptotic analysis Dynamics Dispersion

Formation of a disordered region at the grain boundary during migration with He atoms

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Science China(Physics,Mechanics & Astronomy) 2017年第4期60卷 78-81页

作者： Shi Yuan Hu Yi Yu Wei Shi Yuan YuHan Wang XiaoLin Shu GuangHong Lu Department of Physics Beihang University Institute of Applied Physics & Computational Mathematics Software Center for high performance numerical simulation

W is considered a potential candidate as a plasma facing ma- terial for future nuclear fusion devices because of its high melting point, low sputtering rate, and low H or He solubility [1-3]. In a fusion environment, W will be in direct contact with heat flux, H/He particle fluxes, and the irradiation of high-energy neutrons, causing several defects to be generated, which decrease the service life of W materials. The grain boundary （GB）, which is an important type of defect, affects the various physical and mechanical properties of ma- terials. In the nuclear environment, the GB can act as a sink for the defects when the material is under irradiation.

关键词： migration sputtering solubility irradiation melting disordered defects candidate facing causing

Regeneration of photovoltaic industry silicon waste toward high-performance lithium-ion battery anode

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Rare Metals 2024年第10期43卷 4948-4960页

作者： Kai Wang Xiao-Bin Zhong Yue-Xian Song Yao-Hui Zhang Yan-Gang Zhang Xiao-Gang You Pu-Guang Ji Kurbanov Mirtemir Shodievich Umedjon Khalilov Gong-Kai Wang Xin Zhang Xing-Liang Yao Feng Li Jun-Fei Liang Hua Wang School of Energy and Power Engineering North University of China Zhongyuan Critical Metals laboratory Zhengzhou University Tianjin Key laboratory of materials Laminating Fabrication and Interface Control Technology School of Material Science and EngineeringHebei University of Technology Arifov Institute of Ion-Plasma and Laser Technologies Academy of Sciences of the Republic of Uzbekistan New Uzbekistan University Arifov Institute of Ion-Plasma and Laser Technologies Academy of Sciences of Uzbekistan University of Antwerp School of Chemistry Beihang University

The diamond-wire sawing silicon waste（DWSSW） from the photovoltaic industry has been widely considered as a low-cost raw material for lithium-ion battery silicon-based electrode,but the effect mechanism of impurities presents in DWSSW on lithium storage performance is still not well understood;meanwhile,it is urgent to develop a strategy for changing DWSSW particles into high-performance electrode *** this work,the occurrence state of impurities presents in DWSSW was carefully analyzed using in situ Ar ion etching technology Then,the novel Si@C@SiOx@PAl-NDC composite was designed through in situ encapsulation *** obtained Si@C@SiOx@PAl-NDC electrode shows a high first capacity of 2343.4 mAh·g-1with an initial Coulombic efficiency （ICE） of 84.4%under current density of 1.0 A·g-1,and can deliver an impressive capacity of 984.9 mAh·g-1after 200 *** numerical simulation modeling calculations,the increase in proportion of Si4+/Si0and Si3+/Si0valence states in SiOxlayer leads to a decrease in von Mises stress,which ultimately improves the cycling structural ***,the porous 2D-3D aluminum/nitrogen （Al/N） co-doped carbon layer and nanowires on SiOxlayer can provide abundant active sites for lithium storage due to its developed hierarchical pores structure,which facilitates ion transport What is more,the performance of Si@C@SiOx@PAl-NDC//LiFePO4full cell shows its great potential in practical application.

关键词： Aluminum/nitrogen co-doped In situ encapsulation Lithium-ion batteries Porous carbon nanowires Sawing silicon waste

Ultra-efficient and parameter-free computation of submicron thermal transport with phonon Boltzmann transport equation

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Fundamental research 2024年第4期4卷 907-915页

作者： Yue Hu Yongxing Shen Hua Bao University of Michigan-Shanghai Jiao Tong University joint Institute Shanghai Jiao Tong UniversityShanghai 200240China

Understanding thermal transport at the submicron scale is crucial for engineering applications,especially in the thermal management of electronics and tailoring the thermal conductivity of thermoelectric *** the submicron scale,the macroscopic heat diffusion equation is no longer valid and the phonon Boltzmann transport equation(BTE)becomes the governing equation for thermal ***,previous thermal simulations based on the phonon BTE have two main limitations:relying on empirical parameters and prohibitive computational ***,the phonon BTE is commonly used for qualitatively studying the non-Fourier thermal transport phenomena of toy *** this work,we demonstrate an ultra-efficient and parameter-free computational method of the phonon BTE to achieve quantitatively accurate thermal simulation for realistic materials and *** properly integrating the phonon properties from first-principles calculations,our method does not rely on empirical material properties *** can be generally applicable for different materials and the predicted results can match well with experimental ***,by developing a suitable ensemble of advanced numerical algorithms,our method exhibits superior numerical *** full-scale(from ballistic to diffusive)thermal simulation of a 3-dimensional fin field-effect transistor with 13 million degrees of freedom,which is prohibitive for existing phonon BTE solvers even on supercomputers,can now be completed within two hours on a single personal *** method makes it possible to achieve the predictive design of realistic nanostructures for the desired thermal *** also enables accurately resolving the temperature profiles at the transistor level,which helps in better understanding the self-heating effect of electronics.

关键词： Submicron thermal transport Boltzmann transport equation Deterministic numerical method Phonon transport Transistors Nanostructured materials

Gamma ray multiplicity of a^(240)Pu solid sphere simulated by JMCT

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Nuclear Science and Techniques 2022年第5期33卷 8-15页

作者： Huan-Huan Ding Fan Gao Chang-Bing Lu Rui Li Chen-Guang Li Zhao-Hong Mo Dun-Fu Shi Ming Su De-Shan Zhao Mao-Bing Shuai Zhong-Hua Xiong Bin-Yuan Xia Yun Bai Institute of materials China Academy of Engineering PhysicsMianyang 621908China The 93147th Unit of PLA Mianyang 621000China CAEP Software Center for high performance numerical simulation Beijing 100088China Institute of Applied Physics and Computational Mathematics Beijing 100088China

Determining the mass of plutonium metal is an important research objective in the field of nuclear material accounting and *** on the 3D neutron and photon transport code JMCT(jointed Monte Carlo Transport),the gamma ray multiplicity of ^(240)Pu was simulated in this study,and the average number of gamma rays leaking from ^(240)Pu solid spheres with different masses was also *** simulation results show that there is a oneto-one correspondence between the average number of gamma rays and the mass of ^(240)Pu solid spheres in the range of 0.50–3.00 *** result provides a basis for using the average number of gamma rays to account for the mass of ^(240)Pu.

关键词： ^(240)Pu JMCT Gammaraymultiplicity Solid sphere mass Surface-to-volumeratio

Simulating heavy fermion physics in optical lattice： Periodic Anderson model with harmonic trapping potential

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Frontiers of physics 2017年第5期12卷 71-80页

作者： Yin Zhong Yu Liu Hong-Gang Luo Center for Interdisciplinary Studies & Key laboratory for Magnetism and Magnetic materials of the MoE Lanzhou University Lanzhou 730000 China LCP Institute of Applied Physics and Computational Mathematics Beijing 100088 China Sof-tware Center for high performance numerical simulation China Academy of Engineering Physics Beijing 100088 China Beijing Computational Science research Center Beijing 100084 China

The periodic Anderson model （PAM）, where local electron orbitals interplay with itinerant electronic carriers, plays an essential role in our understanding of heavy fermion materials. Motivated by recent proposals for simulating the Kondo lattice model （KLM） in terms of alkaline-earth metal atoms, we take another step toward the simulation of PAM, which includes the crucial charge/valence fluctuation of local f-electrons beyond purely low-energy spin fluctuation in the KLM. To realize PAM, a transition induced by a suitable laser between the electronic excited and ground state of alkaline-earth metal atoms （^1S0←→^3P0） is introduced. This leads to effective hybridization between local electrons and conduction electrons in PAM. Generally, the SU（N） version of PAM can be realized by our proposal, which gives a unique opportunity to detect large-N physics without complexity in realistic materials. In the present work, high-temperature physical features of standard [SU（2）] PAM with harmonic trapping potential are analyzed by quantum Monte Carlo and dynamic mean-field theory, where the Mott/orbital-selective Mott state was found to coexist with metallic states. Indications for near-future experiments are provided. We expect our theoretical proposal and （hopefully） forthcoming experiments will deepen our understanding of heavy fermion systems. At the same time, we hope these will trigger further studies on related Mott physics, quantum criticality, and non-trivial topology in both the inhomogeneous and nonequilibrium realms.

关键词： optical lattice heavy fermion Mort transition