Reliability assessment of innovative designs in automotive industry

Car manufacturers have to introduce innovative designs during new product development. Field reliability of these new products must be achieved and demonstrated before the start of production. As the design is innovative, this demonstration cannot be based on field and warranty results of existing engines. To overcome this difficulty, the present paper presents a method based on numerical simulations, and two aspects are studied. The reliability of mechanical components is assessed, taking into account the manufacturing processes variability. This is performed with numerical reliability based design (RBD) methods such as the first or second order reliability methods (FORM/SORM). Loads applied by customers are also evaluated according to typical car usage and the specificities of engine behaviour generated by the new concept. The combination of these two types of information provides an evaluation of the future field reliability of the new concept. Results such as parameter sensitivities also help to improve reliability during development by optimizing the design or the manufacturing process. This numerical approach is illustrated in an example of a manufactured steel exhaust manifold.     

Serielle Stückfertigung von Bauteilen aus textilbewehrtem Beton

Serial Batch Production of Building Members Made of Textile Reinforced Concrete Within a research project production techniques were investigated to produce building members made of textile reinforced concrete in a batch production. Laminating, casting, spraying and spinning techniques have been evaluated as well as a combination of these methods. In the beginning the main focus was the production and manufacturing technique with the adjustment of fine grained concrete and fabrics to the respective production technique and the development and choice of distance holders. In order to investigate the manufacturing technique specimens were comprehensively produced by means of selected production techniques. This contains the choice of an adequate production technique, the design of the selected building members, the production of the utilised fabrics as well as the production and testing of the building members. This procedure was carried out for the production of elements of an integrated formwork and spun concrete tubes.     

Von der Bauteilfügung zu leichten Tragwerken: Trocken gefügte Flächenelemente aus UHPFRC

Light‐Weight Structures made of thin walled, dry jointed surface elements made of UHPFRC With the development of novel jointed, thin walled and thus light components the resource‐efficient use of ultra‐high performance fiber‐reinforced fine grained concrete in structures can be realized. The manufacturing of modular and efficient UHPFRC components is achieved by the digital workflow as a result of digital design, calculation and CNC‐controlled manufacturing technology. By linking lightweight concrete components with new, high‐precision non standardized joints, such components can be connected material and force flow compatible with each other. The results with dry jointed T‐beams show the manufacturability and the potential of the dry jointing system on a large scale. When checking the load capacity of thin‐walled construction elements, the influence of fiber reinforcement must be especially considered.     

Multi-objective and probabilistic decision-making approaches to sustainable design and management of highway bridge decks

The aging and deterioration of highway bridges and the new requirements for sustainable infrastructures and communities require innovative approaches for their management that can achieve an adequate balance between social, economic and environmental sustainability. This paper presents a multi-objective decision-making approach for the sustainable design and management of highway bridge decks, which can consider several and conflicting objectives, such as the minimisation of owner's costs, users costs, and environmental impacts and uses goal setting and compromise programming to determine the satisficing and compromise solutions that yield the best trade-off between all competing objectives. The proposed approach is based on robust reliability-based mechanistic models of the deterioration and service life of reinforced concrete bridge decks, which include diffusion models for the prediction of chloride ingress into concrete and steel corrosion and thick-walled cylinder models for the prediction of stresses induced by the accumulating corrosion products in the concrete cover. The proposed approach is illustrated on the life cycle design and management of highway bridge decks using normal and high performance concrete. It is shown that the high performance concrete deck alternative is a Pareto optimum, while the normal concrete deck is found to be a dominated solution in terms of life cycle costs and environmental impacts.     

预制混凝土构件结构性能的统计分析

分析北京地区一些构件厂历年产品试验结果和影响因素，可以得知现有预制构件存在的问题，这些问题的解决将有助于预制构件的技术进步和产品的换代。     

Intelligence approach to production planning system for bespoke precast concrete products

Bespoke precast concrete products are widely used components of construction projects. These products implement the offsite prefabrication technology that offers a unique opportunity for innovation and cost savings for construction projects. However, the production process from design to manufacturing contains uncertainties due to external factors: multi-disciplinary design, progress on construction site. The typical workload on bespoke precast factories is a complex combination of uniquely and identically designed products, which have various delivery dates and requirement of costly purpose-built moulds. In this context, this research is aimed to improve the efficiency of the process by addressing the production planning because it has a significant impact to the success of the production programme. An innovative planning system and its prototype called ‘Artificial Intelligence Planner’ (AIP) are developed. AIP is capable of two functionalities. The first is a data integration system that encourages the automation in the planning process. The other is a decision support system for planners to improve the efficiency of the production plans. These functionalities reinforce each other to deliver optimum benefits to precast manufacturers. AIP have employed artificial intelligence technologies: neural network and genetic algorithm to enhance data analyses for being a decision support for production planning. The outcomes of the research include shortened customer lead-time, in-house repository of production knowledge, and achievement of the optimum factory's resource utilisation.     

JH型增效减水剂的试验和应用

在混凝土中掺入占胶结料总量0.6％的增效减水剂,可减少水泥用量30～40 kg/m3,相应增加30～40kg骨料,在外加剂用量不变的情况下,可得到工作性能良好、强度不下降的混凝土,不仅降低了生产成本,而且混凝土耐久性也得到一定提高.因此,混凝土增效减水剂是一种值得推广的新材料.     

浅谈人工砂混凝土特点及其在水利工程中的应用

人工砂是一种新型水利工程建设用砂。正确使用人工砂的混凝土有利于胶凝材料与骨料之间的结合,实现人工砂混凝土的高性能化。本文主要探讨目前人工砂生产及水利工程施工中存在的主要问题和解决对策。     

Hybridbrücken mit blockverleimtem Brettschichtholz

Hybrid bridges with log‐glued‐laminated timber. In Germany, timber as load‐bearing element of bridges is only used for the construction of foot‐ and bicycle viaducts. The development of new timber‐based products and modern technologies gives interesting chances for timber bridge‐building in future. Main beams with high stiffness and stability of dimension can be produced by log‐glued lamination of timber. Efficient hybrid cross‐sections of superstructures as timber‐concrete‐composite constructions can be made by the combination of beams consisting of log‐glued‐laminated timber and concrete deck slab. For road bridges, these hybrid cross‐sections could be used alternatively to conventional methods of construction. The following paper gives a review of the development status of timber‐concrete‐composite construction in bridge building and shows static and constructive specifics.     

Gradientenbetontechnologie

The technology of graded concrete – From the development of concrete mixtures and the conceptual design to the automatized manufacturing In accordance with the principle form follows force, the DFG Priority Programme (SPP) 1542 – Leicht Bauen mit Beton – focuses on energy efficient building elements which are designed specifically for desired operational demands. This concept is a specific adaption of the component's inner structure and works in parallel to the optimization of its outer shape which is often limited due to the outer geometry of slabs, walls and supporting pillars. The technology of graded concrete provides an innovative possibility to adapt the inner structure of a concrete component in order to meet defined static and structural‐physical requirements. The challenging demands imposed by the technology of graded concrete require a holistic approach including the development of the concrete mixtures, the design of the building components and finally the automatized manufacturing. In collaboration between the departments ILEK, IWB and ISYS of the University of Stuttgart a complete process chain for the manufacturing of functionally graded concrete components was realized. This approach for concrete results in fully recyclable building elements with significant savings in mass and energy.     

水泥与混凝土制品的蒸汽养护生产关键技术进展

使用水泥与混凝土制品可以提高建筑工程施工效率,其中许多制品需要进行蒸汽养护以提高早期强度,加快模具周转。蒸汽养护为水泥混凝土制品生产中的一个关键环节,科学合理的蒸养制度与工艺是生产高质量水泥混凝土制品的重要前提之一,但很多水泥混凝土制品生产企业对蒸汽养护的重要性认识不足,生产与管理经验缺乏,导致生产的水泥混凝土制品质量不能满足设计要求。通过对水泥混凝土制品的蒸汽养护工艺、外加剂使用、裂缝控制等技术现状与发展趋势进行了阐述,希望对水泥与混凝土制品行业发展起到积极作用。     

高耐久性的聚合物纤维混凝土的性能及应用

纤维混凝土（FRC）对混凝土结构的耐久性有明显加强的作用,可以通过延长建筑物的使用寿命,节约建筑物维护和维修的费用．探讨一种新型的聚合物合成纤维水泥基复合材料ECC的工作性能和应用现状．大量研究表明PVA纤维混凝土可以通过牺牲部分抗压强度来提高材料抗裂性能．因此,如果在工程施工中,梁、板等受拉构件或者混凝土钢筋保护层等需要进行耐久性设计的构件使用ECC材料,会取得显著的抗裂性能,提高混凝土构件的耐久性,而以抗压强度起主要作用的抗压构件则建议谨慎使用．     

Classification of production systems for industrialized building: a production strategy perspective

The purpose is to develop a matrix for classifying production systems for construction with various degrees of industrialization. Previous attempts to classify industrialized production systems for construction focus on dimensions such as the design process, the product technology, or the supply chain structure, but none of them acknowledge the importance of how orders are actually won in the market and that different market segments have different requirements. Using production strategy theory as a base, a matrix is developed linking market requirements, via the product offering, to the design of the production system. The matrix positions typical production systems based on their respective degrees of product standardization and volumes relative to the degree of offsite production. Similar to production systems in manufacturing, production systems for construction also deliver manufacturing outputs at different levels, indicating that the choice of production system will affect the competitiveness of the company. The applicability of the matrix is exemplified through three case illustrations of concepts for industrialized building, and these show that the matrix can be used to analyse the production systems’ relative strengths and weaknesses. The matrix can also be used as a guide when developing new, or adjusting existing, production systems for industrialized building so that they will match market requirements and offer competitiveness.     

A model for the analysis of data-driven innovation and value generation in smart cities' ecosystems

Smart cities are key elements to cope with certain of the largest challenges facing society, such as overpopulation, transport, pollution, sustainability, security, health, and the creation of new firms. Smart cities' portals offer a great amount of data that can be used by the private and public entities to create new services. These data are also a valuable source for the deployment of big data businesses. In this article, a model is presented demonstrating how the data released by the smart cities creates value for the citizens and society. The model operates using three stages. The first one shapes the release of data by the smart city, and it includes several of the dimensions that make data appealing for reuse. The second stage analyses the mechanisms to create innovative products and services. The last stage explains how these products and services impact its society.     

Wealth creation from design

The UK adds much less value per manufacturing employee than its competitors. Value is added by good management and, even more, by good design. The Design Council believes that the UK has the best design sector in the world. So what is the way forward? The authors summarise the contents and discussion of an IEE colloquium on 'Wealth creation from design' (1995). The conclusion drawn from this event are summarised and include the following: More money spent at the early stages of a design project saves its cost, many times over, in development and manufacturing costs; the tendency to spend increasing amounts as design proceeds from conception (1%), through evaluation (10%), to realisation (89%), must be reversed; establishing the design specification is one of the most important stages of design and the effort required to do this must not be limited; method in design will produce better products     

Innovative Betone für Holz‐Beton‐Verbundkonstruktionen

Innovative concretes for timber‐concrete composite constructions. Timber‐concrete composite constructions are currently applied mainly for new buildings or when strengthening existing timber beam slabs. The load bearing capacity of timber‐concrete composite slabs is essentially affected by the material properties of the concrete slab and timber beam itself as well as the efficiency of bond between both parts. As nowadays a wide spectrum of different innovative concretes is available their applicability for timber‐concrete composite constructions has to be verified. In the following the focus is set for self‐consolidating concrete, steel fibre reinforced concrete, structural lightweight concrete, high‐strength and ultra high‐strength concrete. The advantages but also disadvantages of these concretes will be explained considering structural, economic and processing aspects and building physics.     

预拌混凝土备用配合比的建立与管理

采用适宜的混凝土原材料并确定它们之间恰当的比例,是生产优质预拌混凝土最基本也是最重要的条件。预拌混凝土生产的特点是材料库存量有限但又必须大量供应产品,等待试配结果然后调整的配合比设计方法已不能适应行业发展的需要。本文探讨采用ISO9001质量管理标准中设计和开发及采购过程控制方法,对常用原材料和常供混凝土,建立备用配合比并加强管理,以确保预拌混凝土质量。     

Durable phosphate-bonded natural fiber composite products

The University of Minnesota Duluth Natural Resources Research Institute (NRRI) and the Wisconsin Business Innovation Corporation (WBIC) conducted a preliminary study to determine the feasibility of producing composite building products utilizing waste pulp and paper mill residues and Ceramicrete^®, an innovative chemically-bonded phosphate ceramic binder developed by the United States Department of Energy’s Argonne National Laboratory (ANL). Specifically, the project was able to demonstrate that waste pulp and paper mill residues can be added to Ceramicrete^® to create durable building materials, determine that the products have potential to meet industry performance standards and consumer acceptance tastes, and determine the preliminary manufacturing costs and economic feasibility of producing the new value-added products. We are beginning an extensive 3-year study to conduct the necessary technical and business/market developments tasks to bring the product concepts to commercialization.     

Applications of natural zeolite to construction and building materials in China

As a main rock mineral, natural zeolite consists of a family of frame-structured alumino-silicate hydrates. This paper presents several research results in China on carrier effect of zeolite, including both an ion-exchange function and an adsorption function, that can be used in the manufacturing of new construction’s products as well as building materials. These products have been successfully applied to overcome some construction difficulties in engineering practice. In the last a few years, two industrial codes (“Technical specifications of application of natural zeolite powder in concrete and mortar (JGJ/T 112-97)” and “Natural zeolite powder used in concrete and mortar (JG/T 3048-1998)”) have been drafted and approved by China Standard Association for construction practice in China. Presently, the annual amount of natural zeolite consumed in the China’s constructions industry is over 30 million tons.     

Untersuchungen zur Genauigkeit von magnetisch induktiven Betondeckungsmessungen

Assessment of the accuracy of concrete cover measurements using Eddy Current devices The use of non‐destructive testing in civil‐engineering (NDT‐CE) is well established to assess as‐built drawings for existing structures as well as for quality assurance of new buildings or in case of concrete repair. To gain reliable results the choice of the appropriate testing method in combination with the correct data assessment is essential. Hence this article starts with the basics of the two typical testing methods for concrete cover measurement with high precision. Methods based on Eddy Current and based on Radar are different. The strengths and limitations of both methods are presented. In the second part the achievable accuracy of concrete cover measurements using Eddy Current will be assessed for the most important parameters that have been varied in a wide range. It is shown how results are influenced by an improper input of the diameter or by the effect of neighbored rebars. At the end of the article it is shown how the deviation of the results can be minimized using the internal neighboring rebar correction of some of the devices. This article does not intend to be a product test rather the influence parameters of measurements close to reality will be identified and quantified how the accuracy of concrete cover measurements is affected.