A Direct Toolpath Constructive Design Method for Controllable Porous Structure Configuration with a TSP-based Sequence Planning Determination

The inherent capabilities of additive manufacturing(AM)to fabricate porous lattice structures with controllable structural and functional properties have raised interest in the design methods for the production of extremely in-tricate internal geometries.Current popular methods of porous lattice structure design still follow the traditional flow,which mainly consists of computer-aided design(CAD)model construction,STereoLithography(STL)model conversion,slicing model acquisition,and toolpath configuration,which causes a loss of accuracy and manufac-turability uncertainty in AM preparation stages.Moreover,toolpath configuration relies on a knowledge-based approach summarized by expert systems.In this process,geometrical construction information is always ignored when a CAD model is created or constructed.To fully use this geometrical information,avoid accuracy loss and ensure qualified manufacturability of porous lattice structures,this paper proposes a novel toolpath-based con-structive design method to directly generate toolpath printing file of parametric and controllable porous lattice structures to facilitate model data exchange during the AM preparation stages.To optimize the laser jumping route between lattice cells,we use a hybrid travelling salesman problem(TSP)solver to determine the laser jumping points on contour scans.Four kinds of laser jumping orders are calculated and compared to select a minimal laser jumping route for sequence planning inside lattice cells.Hence,the proposed method can achieve high-precision lattice printing and avoid computational consumption in model conversion stages from a geomet-rical view.The optical metallographic images show that the shape accuracy of lattice patterns can be guaranteed.The existence of“grain boundaries”brought about by the multi-contour scanning strategy may lead to different mechanical properties.

OPTIMAL DESIGN OF A 6-AXIS FORCE TRANSDUCER BASED ON STEWART PLATFORM RELATED TO SENSITIVITY ISOTROPY

The design method of a 6-axis force robot's transducer based on the Stewartplatform is detailed. For this purpose, the sensitivity isotropy evaluation criteria of thetransducer are defined, and by the aid of computer, the relationships between the criteria and theparameters of all the transducers based on the Stewart platform are investigated within thegeometric model of the solution space, which can provide the theoretical background for the optimalconstruction design of the 6-axis force transducer related to the sensitivity isotropy.

Radial Tire Construction Design Method Based on Finite Element Simulation

The simulation of 295/80R22. 5 tire building process from tire building to curing was developed using ABAQUS software,which covered four stages: gluing of components on main drum,gluing of components on auxiliary drum,building process of green tire and shaping process of green tire. Results showed that material distribution of the simulated structure had good consistence with the real tire structure. Therefore,the tire building process simulation can be used to judge the rationality of tire construction design and to determine the shapes of different tire components. In order to optimize the construction design,a reverse simulation method was proposed to design the semi-product components such as apex,tread,and shoulder pad. The semi-product components determined by utilizing the reverse simulation method were assembled again into a tire. Results show that the simulated material distribution is consistent with the material distribution of design tire,which proves effectiveness and reliability of the reverse simulation method.

Design and Construction of The Great-West Dyke in Lianyungang Port

The The Great-West Dyke with a length of 6.7 km, the largest sea wall in China, was completed in June, 1994. This paper introduces structure options of nibble mound sea wall on soft foundation and a new type of armour block-hexagon multihole block (HMB) and a new method of treatment for soft foundation by using underwater explosion. Construction practice of some projects in China shows that by using this method good effect of treatment and marked economic benefit can be achieved by using this method.

Design and Construction of the Power Plant Multi-flue Chimneys in East China Area

This paper mainly introduces the designand construction of the multi-flue chimneysof Beilungang Power Plant, ShidongkouSecond Power Plant and Waigaoqiao PowerPlant which have been used in East Chinaarea. This paper contains the generalsituation of construction, material selection,lifting scheme of steel inner flue, designfeatures and construction method. It could bereferential to concerned design andconstruction companies.

Performance Comparisons of Five Different SPF Mouse Transport Containers

[Objectives]This study aimed at providing gist for selecting qualified transport containers by comparing the performance of common SPF mouse transport containers at home and abroad,and laying a foundation for subsequent improvement of transport containers.[Methods]In this study,5 different transport containers were selected,and their microbial filtration performance,ventilation,sterilization method and flux,and other related design and construction were analyzed.[Results]The results showed all 5 SPF mouse transport containers can provide enough air for the survival of mouse and protect them from bacterial infections.Transport container B and D are superior to others on one-time sterilization flux and deformation degree after autoclaving.Furthermore,taking into account the related design and construction of these transport containers,such as viewing window and carrying handle,the result of comprehensive comparison is that the transport container D>A>E>C>B.[Conclusions]In summary,the 5 SPF transport containers tested in this study can all satisfy the basic demand of SPF mouse transportation,but each transport container has its own advantages and disadvantages on storage space,deformation degree after autoclaving and other aspects.Thus,SPF mouse transport containers should be selected by different demand.

HISTORICAL PROCEDURES AND G-DSG METHOD BASED MANUFACTURING PLANNING

Oriented to CAD/CAM seamless integration, this paper presents an idea for synthetically considering the qualitative history model, which represents the whole course of modeling, and the quantitative geometry model, which contains the extended Brep model, CSG and feature pedigree. History model building captures in background the dynamic interactive definition of engineering requirement and then explicitly conveys the original intention to successive application layers, which is conductive to the decision support of manufacturing planning in not only automatic geometry re constructing but also machining set up. G DSG theory as an earlier achievement is applied to generate the topology independent generalized mid model as an input to manufacturing planning, which is therefore simplified and its accuracy is simultaneously improved. Manufacturing planning lays emphasis on optimizing the mapping in both geometry and function from part itself to detail machining scheme. Comparatively, process planning pays more attention to the mapping to those items like tool, fixture, etc. Theoretically, such an idea is also beneficial to realizing the parametric NC machining trajectory generation and maintaining its dynamic consistency with the update of the design model.[WT5”HZ]

Towards digital architecture,engineering,and construction(AEC)industry through virtual design and construction(VDC)and digital twin

The architecture,engineering,and construction(AEC)industry is undergoing a substantial change,and the tech-nological advancements are shaping the future of this industry.Over years,numerous tools have been developed based on building information modeling(BIM)and the Internet of Things(IoT)to manage a variety of tasks and activities within different construction and operational phases in the AEC industry.Recently,with the advent of novel internet-enabled technologies in providing the ability of real-time connectivity,researchers have started to develop virtual design and construction(VDC)and digital twin approaches to remotely monitor,control,and optimize different work progresses and activities in real-time at any work level in the AEC industry.This paper presents a reference model to illustrates the main advantages and applications of VDC and digital twin,and to demonstrate their trends and anticipated cost savings in the AEC industry at a global level.These technological advancements along with augmented reality(AR)and virtual reality(VR)can offer the unique benefit of real-time monitoring of the current status as well as predicting the future of any physical structure at any level of work.The global demand and usage of these technological advancements will lead to great cost savings in the AEC industry which would be US$950 million in design and construction and US$400 million in operation and maintenance phases in the non-residential AEC industry in 2025.This paper also discusses the future challenges of VDC and digital twin in the industry.As a main line of future research,these technologies can simultaneously be utilized with artificial intelligence to enable human-centered decision making to automate and optimize work progresses.Such integrations of VDC,digital twin,artificial intelligence,and human-centered approaches will shape the future of the AEC industry and provide numerous research opportunities in this domain.

General review of National Digital Library development in the National Library of China

As an important part of National Digital Library(NDL),the National Digital Library Project(NDLP),which was launched in 2005,has attracted wide attention of the society in general.This paper introduces the general situation of the project from the following aspects,namely,the characteristics,objectives and contents.It also expounds on the basic ideas and the overall structure of the project and gives an introduction to the design of its basic platform,its application platform,its business management system and its standardization control system.In this paper,the digital resources construction and service delivery of the National Library of China(NLC)are introduced to cover both its present operation as well as those in conjunction with the opening of its new library building during its second-phase of library development.Finally,the most important and difficult point in the construction of the National Digital Library Project is analyzed from the following four perspectives:1)The long-term preservation of digital resources;2)the construction of knowledge organization system;3)the organic integration of the digital library and the traditional library;and 4)the risk of project management and system integration.

Materials-oriented integrated design and construction of structures in civil engineering—A review

Design is a goal-oriented planning activity for creating products,processes,and systems with desired functions through specifications.It is a decision-making exploration:the design outcome may vary greatly depending on the designer’s knowledge and philosophy.Integrated design is one type of design philosophy that takes an interdisciplinary and holistic approach.In civil engineering,structural design is such an activity for creating buildings and infrastructures.Recently,structural design in many countries has emphasized a performance-based philosophy that simultaneously considers a structure’s safety,durability,serviceability,and sustainability.Consequently,integrated design in civil engineering has become more popular,useful,and important.Material-oriented integrated design and construction of structures(MIDCS)combine materials engineering and structural engineering in the design stage:it fully utilizes the strengths of materials by selecting the most suitable structural forms and construction methodologies.This paper will explore real-world examples of MIDCS,including the realization of MIDCS in timber seismic-resistant structures,masonry arch structures,long-span steel bridges,prefabricated/on-site extruded light-weight steel structures,fiber-reinforced cementitious composites structures,and fiber-reinforced polymer bridge decks.Additionally,advanced material design methods such as bioinspired design and structure construction technology of additive manufacturing are briefly reviewed and discussed to demonstrate how MIDCS can combine materials and structures.A unified strengthdurability design theory is also introduced,which is a human-centric,interdisciplinary,and holistic approach to the description and development of any civil infrastructure and includes all processes directly involved in the life cycle of the infrastructure.Finally,this paper lays out future research directions for further development in the field.

Full-field x ray nano-imaging system designed and constructed at SSRF

Full-field x ray nano-imaging（FXNI） is one of the most powerful tools for in-situ, non-destructive observation of the inner structure of samples at the nanoscale. Owing to the high flux density of the third-generation synchrotron radiation facility, great progress is achieved for FXNI and its applications. Up to now, a spatial resolution of20 nm for FXNI is achieved. Based on the user operation experiences over the years at the Shanghai Synchrotron Radiation Facility（SSRF） x ray imaging beamline, we know lots of user experiments will rely on a large range of spatial resolutions and fields of view（FOVs）. In particular, x ray microscopes with a large FOV and a moderate spatial resolution of around 100 nm have a wide range of applications in many research fields. Driven by user requirements, a dedicated FXNI system is designed and constructed at the SSRF. This microscope is based on a beam shaper and a zone plate, with the optimized working energy range set to 8–10 ke V. The experimental test results by a Siemens star pattern demonstrate that a spatial resolution of 100 nm is achieved, while an FOV of50 μm is obtained.

COMPUTER PROGRAM FOR DIRECTED STRUCTURE TOPOLOGY OPTIMIZATION

To compensate for the imperfection of traditional bi-directional evolutionary structural optimization, material interpolation scheme and sensitivity filter functions are introduced. A suitable filter can overcome the checkerboard and mesh-dependency. And the historical information on accurate elemental sensitivity numbers are used to keep the objective function converging steadily. Apart from rational intervals of the relevant important parameters, the concept of distinguishing between active and non-active elements design is proposed, which can be widely used for improving the function and artistry of structures directly, especially for a one whose accurate size is not given. Furthermore, user-friendly software packages are developed to enhance its accessibility for practicing engineers and architects. And to reduce the time cost for large timeconsuming complex structure optimization, parallel computing is built-in in the MATLAB codes. The program is easy to use for engineers who may not be familiar with either FEA or structure optimization. And developers can make a deep research on the algorithm by changing the MATLAB codes. Several classical examples are given to show that the improved BESO method is superior for its handy and utility computer program software.

Ionic Covalent Organic Framework:What Does the Unique Ionic Site Bring to Us?

Ionic covalent organic frameworks featuring both crystallinity and charged sites have arose tremendous attention from scientific community. The adjustable textural structures, well-defined channels and abundant charged sites of ionic COFs facilitate great potential in diverse aspects, such as separation, ion conduction, sensing, catalysis and energy storage. In this review, we first introduced the design and construction of ionic covalent organic frameworks(COFs), and classified them according to the types of charged sites. We focused on the various applications of ionic COFs in diverse fields. The structure-function relationship was also explored in detail. Finally, the opportunities and challenges of ionic COFs were summarized to provide guidance for better design and application of ionic COFs.

Particle swarm optimization model to predict scour depth around a bridge pier

Scour depth around bridge piers plays a vital role in the safety and stability of the bridges.The former approaches used in the prediction of scour depth are based on regression models or black box models in which the first one lacks enough accuracy while the later one does not provide a clear mathematical expression to easily employ it for other situations or cases.Therefore,this paper aims to develop new equations using particle swarm optimization as a metaheuristic approach to predict scour depth around bridge piers.To improve the efficiency of the proposed model,individual equations are derived for laboratory and field data.Moreover,sensitivity analysis is conducted to achieve the most effective parameters in the estimation of scour depth for both experimental and filed data sets.Comparing the results of the proposed model with those of existing regression-based equations reveal the superiority of the proposed method in terms of accuracy and uncertainty.Moreover,the ratio of pier width to flow depth and ratio of d50 (mean particle diameter)to flow depth for the laboratory and field data were recognized as the most effective parameters,respectively.The derived equations can be used as a suitable proxy to estimate scour depth in both experimental and prototype scales.