The design, manufacture and application of multistable mechanical metamaterials-a state-of-the-art review

Multistable mechanical metamaterials are a type of mechanical metamaterials with special features,such as reusability,energy storage and absorption capabilities,rapid deformation,and amplified output forces.These metamaterials are usually realized by series and/or parallel of bistable units.They can exhibit multiple stable configurations under external loads and can be switched reversely among each other,thereby realizing the reusability of mechanical metamaterials and offering broad engineering applications.This paper reviews the latest research progress in the design strategy,manufacture and application of multistable mechanical metamaterials.We divide bistable structures into three categories based on their basic element types and provide the criterion of their bistability.Various manufacturing techniques to fabricate these multistable mechanical metamaterials are introduced,including mold casting,cutting,folding and three-dimensional/4D printing.Furthermore,the prospects of multistable mechanical metamaterials for applications in soft driving,mechanical computing,energy absorption and wave controlling are discussed.Finally,this paper highlights possible challenges and opportunities for future investigations.The review aims to provide insights into the research and development of multistable mechanical metamaterials.

Practice Teaching Reform of Mechanical Design and Manufacture and Its Automation Specialty under Transformation and Development

With the development of the times, undergraduate colleges and universities begin to transform and develop to adapt to the changing society, and put forward new requirements for practical teaching strategies, especially for applied undergraduate colleges. The reform of practical teaching is particularly important. Under the development of education transformation, the reform of mechanical design and manufacture and the practice teaching of automation specialty also occupy a very important position. Through the understanding of the reform of the practical teaching of this specialty, the effect of the reform is observed, and a reasonable teaching scheme is put forward to promote the steps of the transformation of the practical teaching.

Practical Analysis of Mechanical Automation Technology in Automobile Manufacturing

In today’s rapidly developing modern society,automobiles,as an important part of transportation and industrial fields,play a pivotal role.With the improvement of people’s living standards and the increase in traffic demand,the automobile manufacturing industry has been continuously developing and growing globally.However,to cope with increasingly fierce market competition and ever-changing consumer demands,the automobile manufacturing industry is also facing the challenges of improving production efficiency,reducing costs,and improving product quality.In this context,automation technology has gradually become a major trend in the automobile manufacturing industry.As an important support of modern industry,automation technology has shown great application potential in many fields.From industrial production to daily life,automation technology can be seen everywhere.In the field of manufacturing,especially in automobile manufacturing,the application of automation technology is getting more and more attention.Automated production lines,intelligent robots,and automated warehousing systems have all changed the face of automobile manufacturing to varying degrees,bringing companies higher efficiency,more stable quality,and greater competitive advantages.The application trend of this automation technology in various fields not only meets the needs of modern industry for efficient,precise,and sustainable development but also provides new ideas and paths for the future development of the automobile manufacturing industry.

Microstructures and mechanical properties of Ti−Al−V−Nb alloys with cluster formula manufactured by laser additive manufacturing

Ti−Al−V−Nb alloys with the cluster formula,12[Al−Ti_(12)](AlTi_(2))+5[Al−Ti1_(4)](V,Nb)2Ti,were designed by replacing V with Nb based on the Ti−6Al−4V alloy.Single-track cladding layers and bulk samples of the alloys with Nb contents ranging from 0 to 6.96 wt.%were prepared by laser additive manufacturing to examine their formability,microstructure,and mechanical properties.For single-track cladding layers,the addition of Nb increased the surface roughness slightly and decreased the molten pool height to improve its spreadability.The alloy,Ti−5.96Al−1.94V−3.54Nb(wt.%),exhibited better geometrical accuracy than the other alloys because its molten pool height was consistent with the spread layer thickness of the powder.The microstructures of the bulk samples contained similar columnar β-phase grains,regardless of Nb content.These grains grew epitaxially from the Ti substrate along the deposition direction,with basket-weaveα-phase laths within the columnar grains.Theα-phase size increased with increasing Nb contents,but its uniformity decreased.Along the deposition direction,the Vickers hardness increased from the substrate to the surface.The Ti−5.96Al−1.94V−3.54Nb alloy exhibited the highest Vickers hardness regardless of deposition position because of the optimal matching relationship between theα-phase size and its content among the designed alloys.

Architectural Design and Additive Manufacturing of Mechanical Metamaterials:A Review

Mechanical metamaterials can be defined as a class of architected materials that exhibit unprecedented mechanical properties derived from designed artificial architectures rather than their constituent materials.While macroscale and simple layouts can be realized by conventional top-down manufacturing approaches,many of the sophisticated designs at various length scales remain elusive,due to the lack of adequate manufacturing methods.Recent progress in additive manufacturing(AM)has led to the realization of a myriad of novel metamaterial concepts.AM methods capable of fabricating microscale architectures with high resolution,arbitrary complexity,and high feature fidelity have enabled the rapid development of architected meta materials and drastically reduced the design-computation and experimental-validation cycle.This paper first provides a detailed review of various topologies based on the desired mechanical properties,including stiff,strong,and auxetic(negative Poisson’s ratio)metamaterials,followed by a discussion of the AM technologies capable of fabricating these metamaterials.Finally,we discuss current challenges and recommend future directions for AM and mechanical metamaterials.

Design for Ti-Al-V-Mo-Nb alloys for laser additive manufacturing based on a cluster model and on their microstructure and properties

In this study,α+βTi-Al-V-Mo-Nb alloys with the addition of multiple elements that are suitable for laser additive manufacturing(LAM)were designed according to a Ti-6Al-4V cluster formula.This formula can be expressed as 12[Al-Ti12](AlTi2)+5[Al-Ti14]((Mo,V,Nb)2Ti),in which Mo and Nb were added into the alloys partially instead of V to give alloys with nominal compositions of Ti-6.01Al-3.13V-1.43Nb,Ti-5.97Al-2.33V-2.93Mo,and Ti-5.97Al-2.33V-2.20Mo-0.71Nb(wt.%).The microstructures and mechanical properties of the as-deposited and heat-treated samples prepared via LAM were examined.The sizes of theβcolumnar grains andαlaths in the Nb-containing samples are found to be larger than those of the Ti-6Al-4V alloy,whereas Mo-or Mo/Nb-added alloys contain finer grains.It indicates that Nb gives rise to coarsenedβcolumnar grains andαlaths,while Mo significantly refines them.Furthermore,the single addition of Nb improves the elongation,whereas the single addition of Mo enhances the strength of the alloys.The simultaneous addition of Mo/Nb significantly improves the comprehensive mechanical properties of the alloys,leading to the best properties with an ultimate tensile strength of 1,070 MPa,a yield strength of 1,004 MPa,an elongation of 9%,and micro-hardness of 355 HV.The fracture modes of all the alloys are ductile-brittle mixed fracture.

Automatic Virtual Entity Simulation of Conceptual Design Results—Part Ⅱ:Symbolic Scheme Simulation

The development of new products of high quality, low unit cost, and short lead time to market are the key elements required for any enterprise to obtain a competitive advantage. This part of the paper presents a methodology to automatically simulate the conceptual design results in the virtual entity form. To the identified basic mechanisms, their kinematic analysis is carried out by matching basic Barranov trusses, and their virtual entities are modeled based on feature-based technique and encapsulated as one design object. Based on the structures of the basic mechanisms and their connections, a space layout to the mechanical system corresponding to the symbolic scheme is then fulfilled. With the preset-assembly approach, all parts in the mechanical system are put onto proper positions where the constraint equations are met according to the space layout results. In this way, the virtual entity assembly model of the mechanical system relative to the symbolic scheme is set up. The approach presented in this paper can not only obtain innovative conceptual conceptual design results, but also can evaluate their performances under 3-D enviroment efficently.

Automatic Virtual Entity Simulation of Conceptual Design Results—Part Ⅰ:Symbolic Scheme Generation and Identification

The development of new products of high quality, low unit cost, and short lead time to market are the key elements required for any enterprise to obtain a competitive advantage. For shorting the lead time to market and improving the creativity and performances of the product, a rule-based conceptual design approach and a methodology to simulate the conceptual design results generated in conceptual design process in automatical virtual entity form are presented in this paper. This part of paper presents a rule-based conceptual design method for generating creative conceptual design schemes of mechanisms based on Yan＇s kinematic chain regeneration creative design method. The design rules are adopted to describe the design requirements of the functional characteristics, the connection relationships and topological characteristics among mechanisms. Through the graphs-based reasoning process, the conceptual design space is expanded extremely, and the potential creative conceptual design results are then dug out. By refining the design rules, the solution exploration problem is avioded, and the tendentious conceptual design schemes are generated. Since mechanical, electrical and hydraulic subsystems can be transformed into general mechansims, the conceptual design method presented in this paper can also be applied in the conceptual design problem of complex mechatronic systems. And then the method to identify conceptual design schemes is given.

Integration of Strain Sensors on Additively Manufactured Implantable Devices

The development of personalized healthcare is rapidly growing thanks to the support of low-power electronics,advanced fabrication processes and secured data transmission protocols.Long-acting drug delivery systems able to sustain the release of therapeutics in a controllable manner can provide several advantages in the treatment of chronic diseases.Various systems under development control drug release from an implantable reservoir via concentration driven diffusion through nanofluidic membranes.Given the high drug concentration in the reservoir,an inward osmotic fluid transport occurs across the membrane,which counters the outward diffusion of drugs.The resulting osmotic pressure buildup may be sufficient to cause the failure of implants with associated risks to patients.Confidently assessing the osmotic pressure buildup requires testing in vivo.Here,using metal and polymer AM(additive manufacturing)processes,we designed and developed implantable drug reservoirs with embedded strain sensors to directly measure the osmotic pressure in drug delivery implants in vitro and in vivo.

Adaptive enhancement design of triply periodic minimal surface lattice structure based on non-uniform stress distribution

The Schwarz primitive triply periodic minimal surface(P-type TPMS)lattice structures are widely used.However,these lattice structures have weak load-bearing capacity compared with other cellular structures.In this paper,an adaptive enhancement design method based on the non-uniform stress distribution in structures with uniform thickness is proposed to design the P-type TPMS lattice structures with higher mechanical properties.Two types of structures are designed by adjusting the adaptive thickness distribution in the TPMS.One keeps the same relative density,and the other keeps the same of non-enhanced region thickness.Compared with the uniform lattice structure,the elastic modulus for the structure with the same relative density increases by more than 17%,and the yield strength increases by more than 10.2%.Three kinds of TPMS lattice structures are fabricated by laser powder bed fusion(L-PBF)with 316L stainless steel to verify the proposed enhanced design.The manufacture-induced geometric deviation between the as-design and as-printed models is measured by micro X-ray computed tomography(μ-CT)scans.The quasi-static compression experimental results of P-type TPMS lattice structures show that the reinforced structures have stronger elastic moduli,ultimate strengths,and energy absorption capabilities than the homogeneous P-TPMS lattice structure.

基于OBE和迭代创新的机械制造及自动化专业人才培养模式改革与实践研究

针对国家对高素质技能人才培养的需求,对基于OBE理念和迭代创新的人才培养模式进行改革,并以机械制造及自动化(模具方向)专业为例,从人才培养目标和核心能力指标、专业课程体系和课程内容、教学模式和教学方法、教学评价体系和教师队伍的培养等方面提出改革设想并进行了教学实践,取得了一定的成效。

机械制造装备设计中翻转课堂教学方法的应用

翻转课堂教学模式遵循“以学生为中心”的理念,可以有效提高学生学习的积极性,培养学生的团队协作能力、自主学习能力、分析和解决问题能力及表达能力等。基于翻转课堂教学模式对大学机械工程专业必修课程——机械制造装备设计课程进行了研究,分析了课程教学现状及教学中存在的问题,探讨了机械制造装备设计课程采用翻转课堂教学模式的教学设计,指出了开展翻转课堂教学过程中出现的问题并提出了持续改进建议。

智能制造背景下的机械自动化技术的创新与应用

机械自动化技术的创新与应用已成为推动制造业转型升级的重要驱动力,在智能制造的驱动下,通过融合信息技术、自动化技术和人工智能等新兴技术,能够有效提高生产效率、降低成本、提升产品质量。为促进机械自动化技术深度应用,分析了智能制造的技术背景,论述了机械自动化技术与智能制造融合创新关键方向,总结了先进智能制造背景下的机械自动化先进技术的应用情况,说明了现阶段技术发展的阻碍及发展建议。

机械设计与低温锂电池全流程数字化智能制造的联系及应用

随着现代制造技术、信息技术和数字化技术的飞速发展,低温锂电池生产迎来了技术升级。对此本文综述了机械设计与低温锂电池数字化智能制造的联系以及技术优化进展。首先分析了低温锂电池产业数字化、智能化的发展流程,包括低温锂电池数字化制造和二阶段的智能化制造;然后重点探讨了机械设计为低温锂电池数字化智能制造产业带来的优化变革。从产业发展角度来看,与机械设计技术深度融合,可以从多个方面优化现有的低温锂电池数字化智能制造技术,对后者的产业结构调整和技术升级具有重要的指导作用。

激光旁轴送气结构设计与分析

目的通过了解激光增材技术,设计一种送丝送气一体化机构,并建立相应模型。方法通过对不同送丝送气机构进行对比分析,设计出3种方案,并通过流体模型分析保护气体氩气的流动情况,最终得出最合理的安装位置。第1种方案是采用送丝机构与送气机构对冲的两轴送丝送气设计方案;第2种方案是采用送丝机构与送气机构同路的设计方案;第3种方案是选择两路送气机构与送丝机成夹角对冲的设计方案。结果在第1种方案中,送丝机构与送气机构的对冲会导致气流紊乱,产生气体流动扩散现象,可以明显看到有一个保护气体比较密集的区域。在第2种方案中,当送丝机构与送气机构同路时,在工作过程中有可能出现防氧化效果不够好的情况。在第3种方案中,两路送气机构与送丝机成夹角对冲可以有效控制氩气的流动,提高氩气的利用率,在这里进行丝材的激光熔覆将会起到最大的防氧化保护作用。结论通过对不同送丝送气机构进行对比分析,最终确定三路送气方案的保护效果最佳。

“专创融合”人才培养模式研究与实践——以“机械设计与制造专业”为例

本文以机械设计与制造专业为例,对该专业“专创融合”人才培养现状及存在问题进行剖析,明确“双创”教育理念,对该专业人才培养重新定位,构建和完善专业人才培养模式和课程体系,探索双创型师资队伍建设路径,建立“线上线下、校企合作”的双创教育共享体系,以期对同类专业“专创融合”人才培养改革提供借鉴与参考。

智能技术在煤矿电气工程自动化中的应用

为进一步探究煤矿电气工程自动化领域的智能发展,结合煤矿电气工程自动化建设的实际需要,以“云平台”的设计理念,整合云计算等功能构建煤矿综合自动化集成系统平台,并整合模糊控制、聚类算法等智能算法,确保智能技术得到有效应用,以此实现对煤矿电气工程领域中相关设备的有效监管作业。

机械设计制造及其自动化技术在智能制造领域的应用

结合机械设计制造及其自动化技术的基本情况,主要对其在智能制造领域的应用进行分析,确保机械设计制造及其自动化技术能发挥相应作用,让机械设计制造及其自动化技术能满足智能制造领域的工作需求,在分析时,主要对机械设计制造及其自动化技术的优势进行研究,再分析其在智能制造领域的应用进行研究,推动智能制造领域的稳健发展。

“课程思政”引领下机制专业双创教育路径研究

研究围绕机械制造及自动化“课程思政”示范专业在高职创新创业教育领域的引领作用,通过教育路径的构建,揭示新的教育模式下如何架构更为科学和人性化的创新创业教育体系,以案例分析和实证研究为抓手,通过对教育路径构建的实证分析,提出并验证了一套新的教育模式和构建方式,对创新创业教育的持续推进、高质量的专业建设提供了有力的理论依据和实践经历,具有重要的理论和实践价值。