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Enabling the transfer matrix method to model serial-parallel compliant mechanisms including curved flexure beams

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International Journal of Mechanical System Dynamics 2024年第1期4卷 48-62页

作者： Mingxiang Ling Lei Yuan Tingjun Zeng xianmin zhang Robotics and Microsystems Center Soochow UniversitySoochowChina Guangdong Key Laboratory of Precision Equipment and Manufacturing Technology School of Mechanical and Automotive EngineeringSouth China University of TechnologyGuangzhouChina

Compliant mechanisms with curved flexure hinges/beams have potential advantages of small spaces,low stress levels,and flexible design parameters,which have attracted considerable attention in precision engineering,metamaterials,robotics,and so ***,serial-parallel configurations with curved flexure hinges/beams often lead to a complicated parametric ***,the transfer matrix method is enabled for analysis of both the kinetostatics and dynamics of general serial-parallel compliant mechanisms without deriving laborious formulas or combining other modeling ***,serial-parallel compliant mechanisms with curved flexure hinges/beams can be modeled in a straightforward manner based on a single transfer matrix of Timoshenko straight beams using a step-by-step *** and numerical validations on two customized XY nanopositioners comprised of straight and corrugated flexure units confirm the concise modeling process and high prediction accuracy of the presented *** conclusion,the present study provides an enhanced transfer matrix modeling approach to streamline the kinetostatic and dynamic analyses of general serial-parallel compliant mechanisms and beam structures,including curved flexure hinges and irregular-shaped rigid bodies.

关键词： compliant mechanisms curved flexure beams transfer matrix method nanopositioner rigid-body dynamics

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山区机场高填方边坡稳定性分析

力学与实践 2024年第1期46卷 89-98页

作者：冯兴姚仰平张健张献民黄信中国民航大学交通科学与工程学院天津300300 北京航空航天大学交通科学与工程学院北京100191

针对山区机场建设中的高填方边坡稳定性问题,本文解决了考虑含石量的统一硬化(unified hardening,UH)模型有限元强度折减法的关键问题:强度折减参数确定、安全稳定系数判断和初始地应力平衡方法确定。应用Mohr-Coulomb模型和考虑含石量... 详细信息

针对山区机场建设中的高填方边坡稳定性问题,本文解决了考虑含石量的统一硬化(unified hardening,UH)模型有限元强度折减法的关键问题:强度折减参数确定、安全稳定系数判断和初始地应力平衡方法确定。应用Mohr-Coulomb模型和考虑含石量的UH模型对山区机场高填方边坡稳定性进行了有限元分析,比较分析了应用两种模型计算的边坡安全稳定系数、位移和应变,得出了机场高填方边坡的稳定性规律,说明了应用考虑含石量的UH模型进行机场高填方边坡稳定性分析的有效性。

关键词：统一硬化模型土石混合料边坡稳定性强度折减法

自适应材料插值在柔顺常力机构非线性拓扑优化中的应用

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机电工程 2024年第5期41卷 913-923页

作者：梁俊文朱本亮张宪民华南理工大学机械与汽车工程学院广东广州510641

为解决柔顺常力机构的非线性拓扑优化中存在的数值不稳定问题,对非线性拓扑优化的材料插值方法进行了研究。首先,根据常力机构的工作特点以及输出特性,分别构建了其非线性拓扑优化的设计域以及优化模型;然后,对数值不稳定问题产生的原... 详细信息

为解决柔顺常力机构的非线性拓扑优化中存在的数值不稳定问题,对非线性拓扑优化的材料插值方法进行了研究。首先,根据常力机构的工作特点以及输出特性,分别构建了其非线性拓扑优化的设计域以及优化模型;然后,对数值不稳定问题产生的原因展开了讨论,从控制应变以避免数值不稳定问题的角度出发,提出了一种新的材料插值模型,模型中引入了参数α,对低密度单元抗变形能力进行了统一调节,并根据最大等效应变给出了一种参数α的自适应调整策略;最后,基于提出的材料插值模型,推导了常力机构优化模型的目标函数敏度表达式,对不同常力区间的常力机构进行了优化,分别对优化结果以及优化效率进行了讨论;并搭建了实验平台,对优化得到的常力机构的实际输出性能进行了验证。实验结果显示:该方法优化得到的常力机构在特定的常力区间内,最大输出力误差为2.3%。研究结果表明:自适应材料插值方法有效地避免了数值不稳定问题,稳定性得到了提升,且优化效率相比于附加超弹材料方法得到了提升。

关键词：柔顺常力机构自适应材料插值非线性拓扑优化数值不稳定目标函数敏度优化效率

基于投影寻踪模型的特高含水油藏剩余油可采潜力评价方法

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油气地质与采收率 2024年第1期31卷 137-144页

作者：刘晨冯其红何逸凡张先敏周文胜中国石油大学(华东)石油工程学院山东青岛266580 海洋石油高效开发国家重点实验室北京100028 中海油研究总院有限责任公司北京100028 中海石油(中国)有限公司天津分公司天津300459

影响特高含水油藏剩余油可采潜力的因素极其复杂,且各因素的影响程度差异明显,常规方法多以剩余油饱和度或剩余油储量丰度等单一指标评价剩余油潜力,难以有效指导特高含水油藏剩余油挖潜。在充分考虑特高含水油藏剩余油可采潜力影响因... 详细信息

影响特高含水油藏剩余油可采潜力的因素极其复杂,且各因素的影响程度差异明显,常规方法多以剩余油饱和度或剩余油储量丰度等单一指标评价剩余油潜力,难以有效指导特高含水油藏剩余油挖潜。在充分考虑特高含水油藏剩余油可采潜力影响因素的基础上,综合表征储层非均质性、剩余油可采储量规模、水淹状况以及油水分流能力的差异,构建了特高含水油藏剩余油可采潜力量化评价指标体系,并考虑不同指标对剩余油可采潜力控制程度的差异,将加速遗传算法与投影寻踪模型相结合来确定各评价指标的客观权重,从而构建了剩余油可采潜力指数,形成特高含水油藏剩余油可采潜力量化评价新方法。以渤海Q油田南区主力产层NmIL砂体为例,开展特高含水油藏剩余油可采潜力量化评价,结果表明,新方法可综合表征不同区域位置的储层物性、可采储量丰度和油水分流能力对剩余油可采潜力的影响,实现了主力产层NmIL砂体剩余油可采潜力分布的差异化定量评价,优势可采潜力区域刻画明显,将其作为NmIL砂体下一步井网加密调整潜力区域,以精准指导加密水平井的部署,为特高含水油藏剩余油挖潜提供了一种全新的分析方法与思路。

关键词：特高含水期剩余油可采潜力指数投影寻踪优势潜力丰度

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Resistive switching and artificial synaptic performances of memristor based on low-dimensional bismuth halide perovskites

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Nano Research 2023年第7期16卷 10108-10119页

作者： Feifei Luo Yanzhao Wu Junwei Tong Fubo Tian xianmin zhang Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) School of Materials Science and EngineeringNortheastern UniversityShenyang 110819China Department of Physics Freie Universität Berlin14195 BerlinGermany State Key Laboratory of Superhard Materials College of PhysicsJilin UniversityChangchun 130012China

Zero-dimensional(0D)-Cs_(3)Bi_(2)I_(9),two-dimensional(2D)-Cs_(3)Bi_(2)Br_(9),and one-dimensional(1D)-Cs3Bi2Cl9 perovskite films have been successfully grown on indium tin oxide(ITO)glass substrates,which were used to fabricate memristors with the structure of Al/Cs_(3)Bi_(2)X_(9)(X=I,Br,and Cl)/ITO *** current three types of memristors exhibited bipolar resistive switching *** the endurance and retention time tests clearly demonstrated the excellent stability of present ***,the ON/OFF ratio of the 0D-Cs_(3)Bi_(2)I_(9)device is close to 104 at the reading voltage of 0.1 V,which is nearly 100 and 1000 times larger than those of the 1D-Cs3Bi2Cl9 device and the 2D-Cs_(3)Bi_(2)Br_(9)device,*** activation energy of halide vacancies in the Cs_(3)Bi_(2)X_(9)(X=I,Br,and Cl)films was calculated using the density functional theory by considering a minimum migration path,demonstrating the dimensionality of the Cs_(3)Bi_(2)X_(9)(X=I,Br,and Cl)film affected the formation and rupture of conductive ***,the short-term plasticity and long-term plasticity of biological synapse were simulated by evaluating the conductance responses of Al/Cs_(3)Bi_(2)X_(9)(X=I,Br,and Cl)/ITO devices under various voltage pulses in *** duration time of long-term plasticity in all the present devices can last for up to 250 *** 0D-Cs_(3)Bi_(2)I_(9)device showed both the highest spikeduration-dependent plasticity and paired-pulse facilitation indexes compared to the other two ***,the 0DCs_(3)Bi_(2)I_(9)device successfully established the associative learning behavior by simulating the Pavlov’s dog experiment.

关键词： perovskite films low-dimension resistive switching artificial synapse

Electrically manipulating magnetization reversal via energy band engineering

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Science China(Physics,Mechanics & Astronomy) 2023年第5期66卷 181-187页

作者： Junwei Tong Yanzhao Wu Feifei Luo Fubo Tian xianmin zhang Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) School of Material Science and EngineeringNortheastern UniversityShenyang 110819China Department of Physics Freie Universität BerlinBerlin 14195Germany State Key Laboratory of Superhard Materials College of PhysicsJilin UniversityChangchun 130012China

Realization of a magnetization reversal by an external electric field is vital for developing ultra-low-power spintronic *** this report,starting from energy band engineering,a general design principle is proposed for achieving electrical manipulation of a nonvolatile 180°magnetization reversal.A half semiconductor(HSC)and a bipolar magnetic semiconductor(BMS)are selected as the model of magnetic layers,whose conduction-band minimum and valence-band maximum are in the same and opposite spin states,*** on the analysis of virtual hopping and tight-binding models,the interlayer coupling of HSC/insulator/BMS devices is successfully tuned between ferromagnetic and antiferromagnetic interactions by varying electric field ***,the interlayer coupling nearly disappears after removing the electric field,proving the nonvolatile magnetization *** first-principles calculations,the feasibility of present design strategy is further confirmed by a representative device with the structure of CrBr3/h-BN/2H-VSe_(2).This design guideline and physical phenomena may open an avenue to explore magnetoelectric coupling mechanisms and develop next-generation spintronic devices.

关键词： magnetic semiconductor magnetization reversal energy band engineering

High-efficiency resistive switch and artificial synaptic simulation in antimony-based perovskite devices

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Science China(Technological Sciences) 2023年第4期66卷 1141-1151页

作者： LUO FeiFei WU YanZhao TONG JunWei XU DaKe QIN GaoWu TIAN FuBo zhang xianmin Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) School of Materials Science and EngineeringNortheastern UniversityShenyang 110819China Department of Physics Freie Universitat Berlin14195 BerlinGermany State Key Laboratory of Superhard Materials College of PhysicsJilin UniversityChangchun 130012China

Three kinds of Cs_(3)Sb_(2)X_(9)(X=I,Br,Cl)perovskite films have been prepared to fabricate the resistive memory devices with the structure of Al/Cs_(3)Sb_(2)X_(9)(X=I,Br,Cl)/indium tin oxide(ITO)*** devices exhibited a bipolar resistive switching behavior at room temperature by applying scanning voltage of 0→1→0→-1.8→0 *** switching voltages in the Al/Cs_(3)Sb_(2)X_(9)(X=I,Br,Cl)/ITO devices gradually decreased with the X from I,Br to Cl due to the different migration rates of halide vacancy in perovskite films,which is confirmed by the first-principles calculations of activation *** ON/OFF ratio under the reading voltage of 0.1 V significantly increased up to 100 in the Al/Cs_(3)Sb_(2)Cl_(9)/ITO device,which is nearly 10 and 3 times larger than that of the Al/Cs3Sb2I9/ITO device and the Al/Cs_(3)Sb_(2)Br_(9)/ITO device,*** endurance cycles and retention time of current devices were evaluated,showing the excellent electrical ***,the three kinds of Al/Cs_(3)Sb_(2)X_(9)(X=I,Br,Cl)/ITO device can successfully simulate the short-term plasticity of biological *** Al/Cs_(3)Sb_(2)Cl_(9)/ITO device showed the highest paired-pulsed facilitation index compared with that of other two devices,which was explored for the longterm plasticity and learning experience processes of *** addition,the Al/Cs_(3)Sb_(2)Cl_(9)/ITO device established associative learning behavior by simulating the Pavlov’s dog experiment.

关键词： perovskitefilms resistive switching artificial synapse

布地奈德联合果糖二磷酸钠和维生素C治疗儿童支原体肺炎合并心肌损伤的疗效

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西北药学杂志 2024年第1期39卷 151-155页

作者：张显敏陈晓红吴秦超金波皖西卫生职业学院附属医院(六安市第二人民医院)儿科六安237000

目的探究布地奈德雾化吸入联合果糖二磷酸钠、维生素C治疗儿童支原体肺炎(mycoplasma pneumonia,MP)合并心肌损伤的临床效果。方法选取87例MP合并心肌损伤患儿作为研究对象,用随机数字表法分为A组(44例)与B组(43例)。2组均行常规治疗,... 详细信息

目的探究布地奈德雾化吸入联合果糖二磷酸钠、维生素C治疗儿童支原体肺炎(mycoplasma pneumonia,MP)合并心肌损伤的临床效果。方法选取87例MP合并心肌损伤患儿作为研究对象,用随机数字表法分为A组(44例)与B组(43例)。2组均行常规治疗,在此基础上B组给予布地奈德雾化吸入联合维生素C治疗,A组给予布地奈德雾化吸入联合果糖二磷酸钠和维生素C治疗。观察2组的疗效、不良反应及啰音消失时间、退热时间和咳嗽消失时间,比较2组治疗前后的心肌酶谱[α-羟丁酸脱氢酶(α-hydroxybutyrate dehydrogenase,α-HBDH)、肌酸肌酶同工酶(creatine kinase-MB,CK-MB)、乳酸脱氢酶(lactate dehydrogenase,LDH)]和炎症指标[降钙素原(procalcitonin,PCT)、C反应蛋白(C-reactive protein,CRP)、白细胞介素6(interleukin-6,IL-6)]。结果A组的治疗总有效率(93.18%)高于B组(76.74%)(P0.05)。结论布地奈德雾化吸入联合果糖二磷酸钠、维生素C治疗儿童MP合并心肌损伤的临床效果较好,可明显改善患儿的肺部症状和体征,抑制炎症,促进心肌功能恢复。

关键词：布地奈德果糖二磷酸钠维生素C 支原体肺炎心肌损伤

Topology Optimization of Compliant Mechanisms with Geometrical Nonlinearities Using the Ground Structure Approach

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Chinese Journal of Mechanical Engineering 2011年第2期24卷 257-263页

作者： ZHAN Jinqing zhang xianmin School of Mechanical and Automotive Engineering South China University of Technology Guangzhou 510640 China

The majority of topology optimization of compliant mechanisms uses linear finite element models to find the structure *** the displacements of compliant mechanisms are intrinsically large,the topological design can not provide quantitatively accurate ***,topological design of these mechanisms considering geometrical nonlinearities is essential.A new methodology for geometrical nonlinear topology optimization of compliant mechanisms under displacement loading is *** elements are chosen to represent the design domain because they are capable of capturing the bending *** nonlinear structural response is obtained by using the co-rotational total Lagrange finite element formulation,and the equilibrium is solved by using the incremental scheme combined with Newton-Raphson *** multi-objective function is developed by the minimum strain energy and maximum geometric advantage to design the mechanism which meets both stiffness and flexibility requirements, *** adjoint method and the direct differentiation method are applied to obtain the sensitivities of the objective functions. The method of moving asymptotes（MMA） is employed as *** numerical example is simulated to show that the optimal mechanism based on geometrically nonlinear formulation not only has more flexibility and stiffness than that based on linear formulation,but also has better stress distribution than the *** is necessary to design compliant mechanisms using geometrically nonlinear topology *** with linear formulation,the formulation for geometrically nonlinear topology optimization of compliant mechanisms can give the compliant mechanism that has better mechanical performance.A new method is provided for topological design of large displacement compliant mechanisms.

关键词： compliant mechanisms topology optimization geometrical nonlinearities the ground structure approach displacement loading