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In this paper, concepts are investigated for tuning material properties and component configurations in order to design structures with unique dynamic characteristics for mitigating blast loads while maintaining or reducing weight. The dynamic response index (DRI) is employed as an occupant injury metric for determining the effectiveness of each blast mitigation configuration that is considered. A finite element model of a notional V-hull structure is used as a numerical example in this study. The material properties and the configuration of the inner bulkheads that connect the V-shaped outer surface with the inner floor are used as design parameters for reducing the DRI at a typical occupant location. In this particular example, it is demonstrated that both the weight of the structure and the DRI can be reduced simultaneously. This is achieved by creating a new structural design that features energy absorbing and decoupling mechanisms among the bulkheads, floor, seat, and the occupant.

International audience; The interferometer of the third generation meteorological satellite is composed by two corner cubes. The specifications, in terms of optical performances - wave front error (WFE) - and mechanical and thermal environments are very stringent compared to the actual knowledge. To answer to the mass, optical and mechanical specifications, a lightweighted hollow corner cube have been designed. An integration process based on enhanced molecular adhesion have been developed and tested in collaboration with CNES and LMA. This process required a fine polishing of the three mirrors of the corner cube before adhesion in order to obtain a very low flatness, roughness and angle precision. The mechanical resistance of the enhanced molecular adhesion process have been validated on three mockups submitted to shock and vibrations. The optical performances have been demonstrate on flight model corner cubes.

Carbon fibre (CF) recycling has been demonstrated to achieve reductions in environmental impacts compared to virgin CF production, but there is limited understanding of the financial viability of recycling and reutilisation of recycled CF (rCF). In this work, cost analysis and identification of market opportunities for rCF are performed by evaluating the cost of recycling, composite manufacture, and applications in automotive industry. Cost impacts of using rCF as a substitute for conventional materials and competitor lightweight materials are assessed over the full life cycle, including in-use implications. Recovery of CF can be achieved at $5/kg and less across a wide range of process parameters, approximately 15% of the cost of producing virgin carbon fibre. The life cycle cost results show that rCF composites, especially aligned rCF composites, give substantial cost reductions relative to virgin CF composites and even steel and aluminium.

This study presents a modelling system to evaluate the impact of weight reduction in light commercial vehicles with diesel engines on air quality and greenhouse gas emissions. The PROPS model assesses the emissions of one vehicle in the aforementioned category and its corresponding reduced-weight version. The results serve as an input to the RIAT + tool, an air quality integrated assessment modelling system. This paper applies the tools in a case study in the Lombardy region (Italy) and discusses the input data pre-processing, the PROPS-RIAT + modelling system runs, and the results.

The paper proposes a method aimed to support Life Cycle Assessment (LCA) in the evaluation of environmental benefits achievable by lightweight design solutions in the automotive field. The study is based on an in-depth calculation of car weight-induced Fuel Consumption (FC) resulting in the Fuel Reduction Value (FRV) coefficient; this is functional in modelling the use stage in a LCA perspective. The research is focused on Gasoline Turbocharged (GT) cars, since to date there is no systematic analysis of weight-induced FC reduction regarding this propulsion technology. The FRV is evaluated for a wide range of vehicle case studies representative of different classes within the 2015 European market. The assessment is performed concentrating on four standardized driving cycles in order to evaluate various driving styles both in the case of primary mass reduction only and in the case of secondary effect (powertrain adaptation in order to maintain vehicle's performance). For the vehicle case studies under consideration, FRV is within the range 0.159–0.237 and 0.252–0.477 l/100 km*100 kg respectively for mass reduction only and secondary effect. Starting from the data obtained, a criterion is refined for estimating the FRV coefficient based on car technical features. Such a method allows to estimate FC reduction precisely by means of the value of FRV closest to the specific application, and it is proposed as a valuable tool for LCA practitioners within the automotive lightweight context.

The existing Community regulation pushes the carmakers to design eco-sustainability of the vehicle over its life cycle to limit the consequences of the current state and the expected growth of the sector. In this sense, one of the primary aim is reducing raw materials consumption and emissions through the adoption of innovative materials and technologies. This implies the need for the carmakers to integrate Design for Environment (DfE) principles at the early Research and Development (R&D) stage. The article presents a concreate example of integration of DfE and LCA methodology application in the R&D process of a vehicle component produced by Magneti Marelli. The study allowed drawing a balance between the advantages of a lightweight solution with respect to the standard one both from performance and environmental point of view.

Recently, sustainability has been a growing concern for many industries and especially for the transportation sector due to it being the second largest energy consumer and largest contributor of anthropogenic greenhouse gas emissions within the European Union. New legal restrictions on the emission rates have forced the automotive sector to examine different fuel-efficient technologies. Vehicle weight reduction is one of the most important methods of improving fuel efficiency and reducing CO 2 emissions. Accordingly, lighter, safer, more fuel efficient, and environmentally sustainable vehicles are a priority for European authorities. In the present work, the passenger seat structure was considered as the area for lightweighting due to its important role in the mass of commercial vehicles in terms of numbers per vehicle. In addition, seat structures presented the best opportunity for weight reduction using new materials and design techniques. Detailed (3D) finite element models of passenger seats were developed for finite element analyses (FEA). To obtain a lightweight and safe seat structure, different materials and thicknesses of profiles were analyzed. Lightweight passenger seat prototypes were developed and an overall 20% weight reduction was achieved including the structural frame, chassis and pillar. In addition, the new passenger seat meets ECE R14 safety norms.

Since sustainability and environmental issues rose lately, lightweighting has been the point of interest for automotive and aerospace sectors. Lightweighting reduces the fuel consumption of the vehicles and as a result of this reduces emissions. Aluminum, especially wrought aluminum alloys, have large potentials for dramatic weight reduction of structural parts while maintaining the safety and performance. Wrought aluminum alloys are used in automotive skin, bumpers and suspension parts etc. Lightweight suspension parts improve the ride quality and handling, additional to fuel consumption and emission reduction. Holistic life cycle approach takes into account the material flows and related information flows in order to achieve these material flows through the life cycle of the components as well as performance characteristics not only in technical and economic terms but also environmental and social terms. It is necessary to have seamless information flow through the life cycle of the components that could be enabled by the closed-loop product life cycle management (PLM). Closed-loop PLM may also help collection of life cycle information which is necessary to generate performance characteristics and distribution of performance characteristics among life cycle actors.

Lightweighting is currently considered as an effective way in improving fuel efficiency and reducing anthropogenic greenhouse gas emissions. The structural applications of lightweight magnesium and aluminum alloys in the aerospace and automotive sectors unavoidably involve welding and joining while guaranteeing the safety and durability of motor vehicles. The objective of this study was to evaluate the lap shear strength and fatigue properties of friction stir spot welded (FSSWed) dissimilar AZ31B-H24 Mg alloy and Al alloy (AA) 5754-O in three combinations, i.e., (top) Al/Mg (bottom), Al/Mg with an adhesive interlayer, and Mg/Al with an adhesive interlayer. For all the dissimilar Mg-to-Al weld combinations, FSSW induced an interfacial layer in the stir zone (SZ) that was composed of intermetallic compounds of Al3Mg2 and Al12Mg17, which led to an increase in hardness. Both Mg/Al and Al/Mg dissimilar adhesive welds had significantly higher lap shear strength, failure energy and fatigue life than the Al/Mg dissimilar weld without adhesive. Two different types of fatigue failure modes were observed. In the Al/Mg adhesive weld, at high cyclic loads nugget pull-out failure occurred due to fatigue crack propagation circumferentially around the nugget. At low cyclic loads, fatigue failure occurred in the bottom Mg sheet due to the stress concentration of the keyhole leading to crack initiation followed by propagation perpendicular to the loading direction. In the Mg/Al adhesive weld, nugget pull-out failure mode was primarily observed at both high and low cyclic loads. © 2012 Elsevier B.V.

This paper describes the design, validation and prototyping of a lightweight crashworthy rail vehicle driver's cab using advanced composite sandwich materials. By exploiting the lightweighting, energy absorption and design integration benefits of composites, an innovative modular cab structure was developed that provides significant savings in mass, cost and part count compared to conventional cab designs.

cited By 21; International audience; The current aim in the development of third-generation steels for lightweighting automotive applications is to increase strength keeping at least the same formability as current steel concepts. In this philosophy, an optimal concept would be one that brings, in addition, a lower density. For this purpose, low-density steels have been designed with important aluminum additions obtaining density reductions of 8–10% or higher in comparison with low-carbon steels. At the levels required for lightweighting, aluminum introduces complex phenomena in steels. Here, some of the effects of aluminum in phase stability, CALPHAD-type modeling, and microstructure development are described, the latter in relation with mechanical properties. Finally, the potential of two families of lightweight steels for automotive applications is assessed by comparison with a steel currently present in automotive structures. © 2014, The Minerals, Metals & Materials Society.

By identifying energy waste streams in vehicles fuel consumption and introducing the concept of lean driving systems, a technological gap for reducing fuel consumption was identified. This paper proposes a solution to overcome this gap, through a modular vehicle architecture aligned with driving patterns. It does not address detailed technological solutions; instead it models the potential effects in fuel consumption through a modular concept of a vehicle and quantifies their dependence on vehicle design parameters (manifesting as the vehicle mass) and user behavior parameters (driving patterns manifesting as the use of a modular car in lighter and heavier mode, in urban and highway cycles). Modularity has been functionally applied in automotive industry as manufacture and assembly management strategies; here it is thought as a product development strategy for flexibility in use, driven by environmental concerns and enabled by social behaviors. The authors argue this concept is a step forward in combining technological solutions and social behavior, of which eco-driving is a vivid example, and potentially evolutionary to a lean, more sustainable, driving culture., The authors acknowledge support from the Foundation for Science and Technology, Lisbon, Portugal, through the 3 degrees Quadro Comunitario de Apoio and the POCTI and FEDER programmes, and under the research Grants PEst-C/MAT/UI0144/2011 and SFRH/BD/33730/2009. Further thanks to the MIT-Portugal Program (www.mitportugal.org), and the COMPETE program from the European Regional Development Fund.

Ponencia presentada en el XIV Congreso Internacional de Ingeniería de Proyectos celebrado en Madrid, 30 de junio, 1 y 2 de julio de 2010 The automotive sector, given the need to reduce energy demand and environmental impact of vehicles, needs to reduce the weight of vehicles. Lightweighting strategy to implement is based on the massive use of plastics and composites, which are lighter than steel and alloys. Use of plastics and composites will significantly reduce emissions during the use stage In that phase energy demand is about 85% of the total energy required during the life cycle of the vehicle. However, it should be assessed whether the improvements are not offset in other stages of the life of the product, in which steels and alloys may have less environmental impact than plastics and composites. In order to work out the fuel savings achieved during the use stage of the vehicle due to the weight reduction, several mathematical models can be used during the design phase. The study of those models will let us know the design parameters that must be considered in order to successfully apply the lightweighting strategy. El sector del automóvil, ante la necesidad de reducir la demanda energética y el impacto medioambiental de los vehículos, necesita aligerar el peso del vehículo. La estrategia de aligeramiento a aplicar se basa en la utilización masiva de plásticos y composites –más ligeros que los aceros y las aleaciones. La utilización de plásticos y composites permitirá reducir significativamente las emisiones durante la etapa de utilización –etapa en la que se demanda aproximadamente el 85% del total de energía del ciclo de vida del vehículo. Sin embargo, se deberá evaluar si las mejoras logradas no son contrarrestadas en otras etapas de la vida del producto en las que losaceros y las aleaciones puedan tener un impacto medioambiental inferior al de los plásticos y composites. Para determinar en la etapa de diseño el ahorro de combustible logrado en la etapa de utilización, debido a la reducción de peso, se pueden utilizar distintos modelos matemáticos. El estudio de estos modelos permitirá conocer las variables de diseño fundamentales que deben considerarse para aplicar con éxito la estrategia de aligeramiento.

Ponencia presentada en el XIV Congreso Internacional de Ingeniería de Proyectos celebrado en Madrid, 30 de junio, 1 y 2 de julio de 2010 European Union, by means of Directive 2000/53/EC on end-of-life vehicles, limits the deposit of waste materials coming from vehicles in landfills. Directive 2000/53/EC provides that, by 1st January 2015, maximum 5% by weight of the vehicle will be deposited in landfills at the end of its useful life. That is, at least 95% by weight of the vehicle must be recovered. Currently, Spain recovers over 85% of vehicle weight. Almost all metallic materials are recovered. That represents approximately 75% of the vehicle. On the other hand, Spain recovers only half of plastics and composites, setting 10% of vehicle weight. If current situation doesn ’t change, the increasing use of plastics and composites in the automotive sector will increase the waste deposited in landfills. To reverse this situation it is necessary to consider the end-of-life of the product during the design stage of future vehicles. This paper discusses those design methodologies that consider the end-of-life and recovery process of complex products as key design aspects. Their study will reveal relevant considerations to the vehicle design process using plastics and composites. La Unión Europea, a través de la Directiva 2000/53/CE relativa a los vehículos al final de su vida útil, limita el depósito de sus residuos en vertedero. La Directiva 2000/53/CE establece que, como muy tarde el 1 de enero de 2015, como máximo un 5% del peso del vehículo al final de su vida útil sea depositado en vertedero. Es decir, el 95% del peso del vehículo deberá ser recuperado. Actualmente en España se recupera más del 85% del peso del vehículo. La práctica totalidad de materiales metálicos son recuperados –aproximadamente el 75% del vehículo. Por el contrario, sólo se recupera la mitad de plásticos y composites –entorno al 10% del peso del vehículo. Si no se modifica la actual situación, la creciente utilización de plásticos y composites en el sector del automóvil supondrá un aumento de los residuos depositados envertedero. Para revertir esta situación, es necesario considerar el fin de vida del producto durante la etapa de diseño de los futuros vehículos. En este trabajo se analizan las metodologías de diseño que consideran el fin de vida y la recuperación de productos complejos como aspectos de diseño fundamentales. Su estudio permitirá establecer aquellas consideraciones útiles para el diseño de vehículos utilizando plásticos y composites.

Based on Pininfarina Nido EV concept, EVolution aims to reduce the vehicle weight through new materials and process technologies, focused on five demonstrators: underbody, front crossbeam, mechanical subframe, shotgun system and door. This paper refers to body structure design strategies using new composite, Al materials and enabled technologies, focusing in particular on demonstrators design and manufacturing. The new front crossbeam geometry of the front shell is adapted starting from the Nanotough design, while the rear shell is specific for EVolution. The subframe demonstrator is redesigned to fulfil mechanical requirements of the part and manufacturing feasibility either. The EVolution door concept consists of two semistructural composite skins including a structural Al frame. The underbody is conceived through an integrated approach, optimising each element for its function. The shotgun component is designed to link parts obtained with different manufacturing technologies and several aluminium alloys in one single component: the structural node demonstrator. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 314744.