Advertisement

Lightweight Design worldwide

, Volume 11, Issue 3, pp 30–35 | Cite as

Study into resource-efficient lightweight design

  • Maik Gude
  • Michael Stegelmann
  • Michael Müller
  • Kurt Demnitz
Materials Resource Efficiency
  • 138 Downloads

The role lightweight design plays in the mobility of the future remains a hotly debated topic. One thing is certain: with changes in mobility behavior come changing demands on vehicles and vehicle components. A study conducted in 2018 under the leadership of TU Dresden now highlights the resulting possibilities and challenges for lightweight design.

Holistic Approach

Initiated by the National Platform for Electric Mobility (NPE), the Research and Technology Center for Resource-Efficient Lightweight Design Structures for Electric Mobility (Forel) has been dedicated to the systemically coordinated further development of lightweight design for use in vehicles of the future since 2013. It aims to develop new methods of design, technologies, and processes as well as ways of directly transferring and exploiting research results in industrial value chains. Building on the findings of the Forel study in 2015 [1] and the research and development findings from a current total of ten technology projects, the latest study investigates the current technological transformation in mobility [2]. To this end, an online survey was conducted with over 220 industry and business participants and ten expert interviews on selected subject areas. The study was conducted under the leadership of the Institute of Lightweight Engineering and Polymer Technology (ILK) of TU Dresden in cooperation with the Laboratory of Materials and Joining Technology (LWF) of the University of Paderborn, the Institute for Machine Tools and Industrial Management (IWB) of TU Munich, the Institute of Mineral Processing Machines (IAM) of TU Bergakademie Freiberg and the Institute of Forming Technology and Lightweight Design (IUL) of TU Dortmund. Following the holistic and interdisciplinary approach of Forel, current developments were analyzed under the four headings of Technology Transformation, Forecasting Ability, Technology Assessment and Ecological Sustainability.

Technology Transformation through Lightweight Design

The survey findings clearly show that different development scenarios are predicted for conventional and alternative drive concepts over the next 10 to 15 years. Moreover, respondents also assume that major changes in usage profiles and ownership patterns will emerge, Figure 1. The transformation of mobility will be characterized by numerous unknown factors for the foreseeable future. However, as lightweight design is not tied to a single drive concept and promises significant efficiency gains, particularly with regard to urban mobility [3], it will continue to play a key role in future, an assumption which the results of the study also reaffirm. Besides a higher level of lightweight design and increasing technical demands, the experts surveyed also expect significant pressure to develop future vehicles and components with environmental sustainability in mind, Figure 2. The experts also expect to see fewer components in vehicles. This suggests that implementing new mobility concepts will change existing value chains and lead to an adjustment in vehicle architectures. The challenges arising for existing vehicle systems and structures can, however, also be seen as an opportunity to use new technologies and materials. It is precisely the holistic approach of systemic, multi-material lightweight design that combines a reduced mass with myriad possibilities for functional integration in order to create an economically meaningful component design, which the technological boundary conditions play a key role in achieving. The survey findings underline the special importance of production flexibility, the ability to simulate processes and automation.
Figure 1

Transformation of individual mobility in 10 to 15 years with regard to drive types and usage behavior (© ILK)

Figure 2

Changing component and vehicle-level requirements in 10 to 15 years (© ILK)

Future computation will be more closely involved with production.

Overall System Manageability

Powerful and efficient development methods are needed to meet complex requirements. A strictly sequential succession of component design, computation, production planning and production start results in extremely long development cycles, which very often impede or even prevent the introduction of innovative technologies into an existing overall system. Forecasting ability becomes crucial to still be able to achieve the required technological transfer while minimizing economic risk. In the study, this is understood to be the numerical simulation of production processes and structural components and their combination. The use of simulation methods is now commonplace. Experts believe that the forecasting ability for metallic materials already covers current requirements in many areas. A somewhat different picture emerges when it comes to Fiber-Reinforced Polymers (FRPs). While it is possible to realistically describe a polymer, numerous specific values and parameters are required compared with metals. The study also shows that experimental tests still need to be performed, regardless of the material. Databases and the use of analytical models represent alternatives, Figure 3. However, these options were used far less frequently among all participant groups. Proven experts were interviewed to gain a better insight, for example, into the future simulation of FRPs. Prof. Chinesta from the ESI Group emphasized that, from the software vendor perspective, it can be assumed that future computation will be more closely involved with production and benefit from digitalization in the process, Interview 1.
Figure 3

Strategies for determining material properties split by participant group (© ILK)

Interfaces Still Only Isolated Solutions

According to the survey participants, virtually linking individual process steps is another challenge for forecasting ability. Experts complain that standard interfaces are often insufficient and that customized standalone solutions, e.g. for mapping tasks, need to be programmed. The combination of different solvers and material models is becoming increasingly important, precisely in light of the growing use of material combinations. Such hybrid structures are also the object of Forel technology projects. For example, a floor assembly based on new types of semi-finished sandwich materials was produced in the Leika project, Figure 4. Important aspects such as complex molding behavior and the production-related occurrence of internal stresses were first investigated numerically, then validated with a demonstrator [4]. The consortium in the Q-Pro project goes one step further. Here, simulation is used to systematically implement quality assurance along the process chain through to the structural inspection of the 3-D hybrid structure, Figure 5. Although today’s computing power remains insufficient for detailed real-time simulation, combining information from production and simulation during post-processing is possible. Once again, the prerequisites for this are data interfaces. In Q-Pro, all relevant data is therefore analyzed and documented together in the browser-based application Detact from Symate. The standardized visualization of results simplifies data analysis as well as the planning and validation of virtual and numerical tests.
Figure 4

Production of the Leika demonstrator in the ILK technical center (© ILK)

Figure 5

Chaining of simulation steps in the Q-Pro project (© ILK)

Ecological Sustainability

A further aspect that will shape lightweight design of the future is ecological sustainability. Both the survey participants and interview partners confirm that this topic found its way onto the agenda before the recent controversies over emission parameters. However, a complex picture emerges as far as the current status of Life Cycle Assessments (LCA) is concerned. On the one hand, there is a clear demand for the ecological assessment of products, but at the same time, the active use of such methods is not widespread practice. This is due firstly to methodological uncertainties and secondly to the lack of available input data, Figure 6. Nevertheless, in an interview, representatives of supplier Brose Fahrzeugteile talk about efforts to take ecology into account at the earliest opportunity in the product development process, Interview 2. Furthermore, the increasing future relevance of LCA is clearly emphasized. Standing in the way of a standardized and transparent approach, however, is the persistent inability of companies to compare their own accounting methods with the results of other manufacturers, Interview 2.
Figure 6

Obstacles to ecological accounting (© ILK)

All of which means the industry lacks uniform general conditions for performing LCA. A broad data pool that may also include sensitive commercial information is necessary to remedy this deficit. With this in mind, it is understandable that the further spread of LCA is difficult. For the institutes involved in Forel, this reaffirms the acute need for research in this area. The open and independent platform Forel, with currently over 90 partners from science and industry, represents an ideal starting point. The methodological development topics that should be prioritized here were subject of discussion in the expert interview with Thinkstep, Interview 3.

The industry lacks uniform general conditions for performing LCA.

Thinking Lightweight Design Long-term

The Forel study 2018 clearly shows that multi-material lightweight design will remain crucial to future mobility. Unlike the public debate, where lightweight design is often reduced to mere weight savings, it is important to note that solution strategies for developing sustainable vehicles for the future must be diverse and, above all, interdisciplinary. The idea of an open and independent platform that underpins Forel thus represents a key prerequisite for systematically developing mobility. The lightweight design roadmap is therefore being constantly updated and enhanced with cooperative projects in close cooperation with the NPE.

The content described here shows only a small excerpt of the comprehensive study findings. Other subject areas include recycling, technology assessment, metal forming and joining technology. The Forel study 2018 can be ordered and accessed online [5].

Interview 1: Prof. Francisco Chinesta (Head of Scientific Committee of the ESI Group)

“A main weakness of composites is the increase in uncertainty along the process chain. The uncertainty accumulates exponentially along the scale differences and variety of involved components and materials. Thus, it is hard to predict how minor fluctuations propagate in the following. […] Instead of trying to model the uncertainty physically, there are also alternative ideas to achieve convergence of reality and simulation. Learning from the data can allow creating a new generation of data-based models, they allow for real-time decision-making, and to simulate from data or from a combination of data and models.”

Interview 2: Andrea Bauersachs (expert for seating concepts and predevelopment) and Sebastian Ross (expert for occupational safety, the environment and production technology at Brose Fahrzeugteile)

“We already assess the ecological impact of all product families in the conceptual phase. However, a complete life cycle assessment can only be performed when the product has been manufactured and the required data are available. The main motivation is comparing further developments with corresponding reference components. Although a comparison across company boundaries would be desirable, the lack of a data pool makes this impossible. In addition, there is no generally accepted definition of accounting limits, in relation to rival products for example.”

Interview 3: Jürgen Stichling (Vice-President Mobility, Energy and Chemicals at Thinkstep)

“An obvious trend is the automation of life cycle assessments, for example the automatic creation of product models based on a bill of materials. […] A further topic is the generation of parameterized models built by external experts so that product developers can also quickly reach a conclusion. Moreover, data availability for the latest lightweight materials must be further improved.”

Notes

Thanks

This research and development project is funded by the German Federal Ministry of Education and Research (BMBF) within the Framework Concept ”Research for Tomorrow’s Production” (02P16Z010 — 02P16Z014) and managed by the Project Management Agency Forschungszentrum Karlsruhe, Production and Manufacturing Technologies Division (PTKA).

References

  1. [1]
    Gude, M.; Lieberwirth, H.; Meschut, G.; Zäh, M.F.; et al.: FOREL-Studie, Chancen und Herausforderungen im Ressourceneffizienten Leichtbau für die Elektromobilität. Plattform FOREL, 2015Google Scholar
  2. [2]
    Gude, M.; Lieberwirth, H.; Meschut, G.; Zäh, M.F.; Tekkaya, E.; et al.: FOREL-Studie 2018 — Ressourceneffizienter Leichtbau für die Mobilität: Wandel — Prognose — Transfer. Plattform FOREL, 2018Google Scholar
  3. [3]
    Beckmann, K.; Holzapfel, H.; et al.: Elektromobilität: Macht der Wandel des Fahrzeugantriebs den Verkehr umweltfreundlich? Version: 2017 Online: http://www.zeit.de/stellungnahme-elektromobilitaet-november-2017.pdf, access: April 04, 2018
  4. [4]
    Paul, C.; Jaschinski, J.; et al.: Effiziente Mischbauweisen für Leichtbau-Karosserien. LEIKA Abschlussbericht. Plattform FOREL, 2017Google Scholar
  5. [5]
    FOREL-Studie 2018. Online: http://www.plattform-forel.de/studie, access: April 13, 2018

Copyright information

© Springer Fachmedien Wiesbaden 2018

Authors and Affiliations

  • Maik Gude
    • 1
  • Michael Stegelmann
    • 1
  • Michael Müller
    • 1
  • Kurt Demnitz
    • 1
  1. 1.TU DresdenGermany

Personalised recommendations