Study of static cushioning properties and construction of a database for static cushioning properties

The rapid advance of computerization in industrial package design has led to a strong tendency toward CAD/CAM systems using personal computers for quick design and trial manufacturing. New tools based on a database of the cushioning properties of packaging materials will be needed for the design of package cushioning. Using a compression testing machine with computer control, an attempt has been made to construct such a database with registered characteristics for 47 samples of foamed polyethylene, foamed polypropylene and foamed polyethylene-polystyrene. This database offers the following functions and is recorded on floppy disk: (i) calculation of static cushioning properties (value); (ii) print-out of the computed results; (iii) drawing characteristic figures for designing package cushioning; (iv) indicating optimum value of static cushioning properties; (v) additional registration of new samples.     

Armoured Selection Decision Support Software

ABSTRACT

Selecting a main battle tank for an army is a lengthy and complex decision-making process. Military procurement staffs use various management and engineering tools to conduct their studies. This article describes a decision support software package that can assist in selecting the best tank from a set of competitors. The package assesses the design features that affect three major performance criteria: firepower, protection, and mobility. The package combines the Expert Choice^? implementation of the analytical hierarchy process with a LOTUS^? spreadsheet.     

工业应用专家系统学习模块的设计

学习功能是提高专家系统（ＥｘｐｅｒｔＳｙｓｔｅｍ）自我更新、自我完善能力的重要途径。本文作者在实践的基础上提出了工业应用ＥＳ学习模块的设计思想，并简单介绍了在该思想下建立的焊接工艺制定专家系统（ＷＰＤＥＳ）的学习功能。     

基于三维轻模型的装配MES系统关键技术

针对现阶段产品设计已经实现三维数字化,但在航空等典型离散行业的制造现场仍以二维工程图为产品制造依据的现实,提出了基于三维轻模型的装配MES系统,将产品设计数据向制造过程延伸,并结合MBD( ModelBased Definition,基于模型的定义)技术实现基于三维轻模型的装配工艺定义,以三维轻模型为车间现场装配生产的...     

Integrated Design For Manufacturing of Braided Preforms For Advanced Composites Part II: 3D Braiding

This paper presents the integrated design of manufacturing of braided preforms by two types of novel 3D braiding technology: 3D Cartesian braiding and novel hexagonal braiding. The principles for design are first introduced and the ensuing software package development is subsequently discussed. The relationships between fiber volume fraction and braiding angle which are key parameters for fiber reinforcement composites were analyzed and compared. Meanwhile, several samples are carried out to verify the software. The result shows it is consistent between theoretical and experimental results. Combined with the Part I: 2D braiding section, many complex shape performs can be made, which will be usefully for design of advanced composites.     

3D打印技术探究

3D打印技术是将三维数字模型分解成若干层平面切片,然后由3D打印机把粉末状、液状或丝状可粘合材料按切片图形逐层叠加,最终堆积成完整物体的技术。文章对3D打印的技术原理、步骤、常用材料、主要技术、发展及建议进行了深层次的探讨。与传统制造技术相比,3D打印技术有很多优势,目前已广泛应用于建筑、工业设计等领域。该技术将会带来全球制造业经济的重大变革。     

Simulation and experimental verification of a drop test and compression test of a gable top package

A finite element framework has been proposed that can be used to simulate both empty paperboard packages and package filled with plastic granulates. A gable top package was made of a commercial paperboard, and material properties needed in the material model were determined. Two simulations were performed, a drop test and a compression test. By comparison between experimental and numerical results, the deformation mechanisms at impact could be identified and correlated to material properties. When the package was filled with granulates, different mechanisms was activated compared with an empty package. The granulates contribute to bulging of the panels, such that the edges became more load bearing compared with the panels. When the edges carried the loads, the importance of the out‐of‐plane properties also increased, and local failure initiation related to delamination was observed. Comparison between experimental and numerical impact forces shows that there are still important things to consider in the model generation, eg, variation of properties within the package, which originate both from material property variations, and the loading history, eg, during manufacturing and handling.     

人体植入医用材料的3D打印技术研究进展

3D打印技术是一种与传统制备方式完全不同的新兴技术,是基于三维数学模型,通过逐层增加材料来实现成型的技术。3D打印技术在个性化设计以及复杂结构产品制备方面具有独特的优势,在人体植入物的结构设计和制造领域具有巨大潜力和研究价值,吸引了国内外工业界、医学界和社会媒体的广泛关注。目前制约该技术发展的主要因素是可打印材料种类有限。综述了几种人体植入医用材料及其3D打印成型技术,如骨支架、心脏血管支架以及药物定向运输材料的3D打印制备技术,并分析了以上技术各自的特点。最后结合各种3D打印成型技术的特点以及几个应用案例,对3D打印在人体植入物医学领域的发展进行了展望。     

Stereolithographic 3D Printing of Ceramics: Challenges and Opportunities for Structural Integrity

This article reviews the current activities at the Montanuniversität Leoben on the design, processing, and characterization of 3D printed advanced ceramics using the lithography-based manufacturing technology. An overview of the challenges and the opportunities offered to improve the mechanical properties of printing ceramics is given. Their brittle failure is analyzed within the framework of linear elastic fracture mechanics, considering specific aspects of additive manufacturing. Several issues associated with the printing process are addressed, such as surface quality, geometry control, influence of printing directions, as well as the need to establish testing protocols for 3D printed parts. Based on the layer-by-layer capabilities of the stereolithographic process, bio-inspired material design concepts are discussed aiming to enhance the mechanical resistance of 3D-printed ceramics. By tailoring the layer architecture and microstructure of the parts, high strength and fracture resistance may be achieved.     

Strain recovery analysis and stiffness verification of non-uniform composite beam with arbitrary cross section and material distribution using VABS

This paper presents a theory related to a two-dimensional linear cross-sectional analysis, recovery relationship, and a one-dimensional nonlinear beam analysis for composite wing slender structure with initial twist. Using VABS including a related theory, the design process of the composite rotor blade has been described. Cross-sectional analysis was performed at cutting point including all the details of geometry and material. Stiffness matrix and mass matrix were linked to each section to make 1D beam model. The 3D strain distributions within the structure were recovered based on the global behavior and load of the 1D beam analysis and visualize numerical results. Comparison between the analytical and experimental results shows that the proposed analytical procedure can provide an accurate and efficient prediction of the both deflection, flexural stiffness, strain of multilayer composite slender structure. Verified comparison results can be used to efficiently design accurate complex slender structure properties for detail design and manufacture. These sentences will appear after the conclusion when an article is finally published.     

Integrated Design for Manufacturing of Braided Preforms for Advanced Composites Part I: 2D Braiding

This paper presents a 2D braiding design system for advanced textile structural composites was based on dynamic models. A software package to assist in the design of braided preform manufacturing has been developed. The package allows design parameters (machine speeds, fiber volume fraction, tightness factor, etc.) to be easily obtained and the relationships between said parameters to be demonstrated graphically. The fabirc geometry model (FGM) method was adopted to evaluate the mechanical properties of the composites. Experimental evidence demonstrates the success of the use of dynamic models in the design software for the manufacture of braided fabric preforms.     

缓冲包装CAD软件研究

介绍了以正方形角垫为主的缓冲包装ＣＡＤ设计软件、并给出了设计实例。     

Specification of gas turbine disc forgings

Abstract

The cost of failures in gas turbine discs, both in human life and financial terms, is particularly high, and it has always been recognized that the component must be fully specified against the design requirement, and totally predictable in operation. This was originally achieved by making a reproducible forging consistent with the design strength assumptions and which approached the engineer's model of the material as ‘elastic, isotropic, and free from defects’. Today's improved understanding of materials behaviour in terms of the relationship between material property and microstructure, together with the designer's need for higher–strength materials, has led to an approach which now recognizes the role of both structure and ‘defects’ within the forging. This, and the need to improve the cyclic properties of components, is now imposing on the forger complex microstructural and quality requirements that can be met only by process control and by a move towards closer-to-size and more complex shape requirements. Future material needs are discussed in relation to controlling the discontinuity behaviour, together with the change in philosophy that this is bringing to the control of the manufacturing process.

MST/255     

Cost/weight optimization of composite prepreg structures for best draping strategy

The application of hand-laid carbon fiber prepreg is very expensive from a labor perspective. Therefore the manufacturing cost should be included in the design process. In this work, we propose a novel optimization framework which contains a draping simulation in combination with a detailed cost estimation package and the calculation of the structural performance based on FE. We suggest applying the methodology in two steps. First, a draping knowledge database is generated in which combinations of seed points and reference angles are evaluated in terms of fiber angle deviation, scrap, ultrasonic cuts and material shear. Second, a cost/weight optimization framework picks the best sets of plies during the subsequent optimization. The methodology is tested by means of a curved C-spar which is designed using plain weave and unidirectional prepreg. Different objectives in the generation of the draping database lead to different design solutions.     

3D printing vertically: Direct ink writing free-standing pillar arrays

Over the last three decades, a variety of additive manufacturing techniques have gradually gained maturity and will potentially play an important role in future manufacturing industries. Among them, direct ink writing has attracted significant attention from both material and tissue engineering areas, where the colloidal ink is extruded and dispensed according to a pre-designed path, usually in the X-Y plane with suitable increments in the Z direction. Undoubtedly, this way of disassembling geometries, simple or complex, can facilitate most of the printing process. However, for one extreme case, i.e. pillar arrays, the size resolution can deviate from both nozzle and design if the common way of slicing and additive manufacturing is used. Therefore, a different printing path is required – directly depositing pillars in a converse gravitational direction. This paper gives multiple examples of printing viscoelastic colloidal ceramic and metal inks uniaxially and periodically into free-standing and height-adjustable pillar arrays. It is expected to inspire the additive manufacturing community that more versatile degrees of freedom and complex printing paths, not confined within only complex shapes, can be achieved by ink-based 3D printing.     

On a proposal for a generic package development process

Globalization pressures have now caused significant changes in the way industrial enterprises are organized and how products are developed, manufactured and brought to market. In global enterprises, the handling, transportation and storage of parts, sub‐assemblies and final products demand for an efficient and effective development of the product–package‐system (PPS). The objective set in this paper is to present the development of a generic package development process that facilitates the establishment of integrated product and package development and also provides a more proactive and holistic approach to the development of new and innovative packages for the global market. In an extensive review of the package development literature and through five multiple case studies within the package manufacturing industry, results on the package development process are generated and, in this paper, presented and synthesized into an updated version of the package development process. The process consists of the phases package planning, package system development, package concept design, package design, production ramp‐up, package system integration and package system production ramp‐up. The package development model proposed here takes its starting point in the development of the package system, thus providing the holistic perspective needed for being truly generic. Being generic in the given context assures or at least facilitates the possibility to support the development of the new and innovative package systems and package designs needed in the product manufacturing industry to enhance competitiveness. Copyright © 2009 John Wiley & Sons, Ltd.     

基于VRML的母线槽布线CAD系统的研究

介绍了基于虚拟现实建模语言VRML的母线布线CAD系统的基本结构、设计思想和关键技术。系统采用了结构化查询语言SQL驱动的专家系统实现了母线槽系统的自动布线，引入了虚拟现实建模语言VRML实现了母线槽系统的三维显示并能进行Internet上实时浏览，极大的缩短了设计周期。     

Development Trends in Additive Manufacturing and 3D Printing

Additive manufacturing and 3D printing tech-nology have been developing rapidly in the last 30 years, and indicate great potential for future development. The promising future of this technology makes its impact on traditional industry unpredictable. 3D printing will propel the revolution of fabrication modes forward, and bring in a new era for customized fabrication by realizing the five "any"s: use of almost any material to fabricate any part, in any quantity and any location, for any industrial field. Innovations in material, design, and fabrication processes will be inspired by the merging of 3D-printing technology and processes with traditional manufacturing processes. Finally, 3D printing will become as valuable for manufacturing industries as equivalent and subtractive manufacturing processes.     

Decision-Analytic Methodology for Cost-Benefit Evaluation of Diagnostic Testers

A modular influence diagram model is proposed as a decision-analytic framework for reasoning about diagnostic testing in the manufacture of mechanical products. The influence diagram ties product design, manufacturing, and testing decisions to field quality, costs and risks. The decision-analytic theory of “expected value of information” is used to evaluate the cost-benefit of alternate testing systems. The structure of the model highlights research directions for engineering economics in evaluating cost-benefit tradeoffs in the product cycle from design, to manufacturing, marketing and field service. An implementation in the IDES (Influence Diagram Based Expert System) illustrates the potential of applying such a planning model to real-time diagnostic decisions in the manufacture of mechanical components for high-speed printers.