DLR.de slide 1 ARENA2036 - Fiber Reinforced Plastic Structures with Functional Integration Institute of Vehicle Concepts, DLR Stuttgart Sebastian Vohrer, Gundolf Kopp, Prof. H. E. Friedrich Daimler AG Verena Diermann, Dr. Thomas Sommer-Dittrich JEC International Conference on Automotive Technologies Knoxville, October 13 th 2016
DLR.de slide 2 DLR German Aerospace Center DLR's mission exploration of the Earth and the solar system research aimed at protecting the environment development of environmentally-friendly technologies to promote mobility, communication and security. 8000 employees are working at 33 research institutes and facilities in 16 locations. Institute of Vehicle Concepts SPACE AERONAUTICS TRANSPORT ENERGY SECURITY
DLR.de slide 3 Idea of ARENA2036: Customer request as impulse for intelligent lightweight construction and agile production CUSTOMER REQUEST CHALLENGE RESEARCH & DEVELOPMENT Individual vehicle & increase of variants bodyshape, powertransmission, equipment High vehicle comfort with Increase in safety infotainment, assistant and security systems The automotive research meets the demand for more and more vehicle variants with a higher comfort level due to a combination of the lightweight construction and adaptable production. All process chain stages will vary. The entire supply chain is subject to change. Rising production costs with volatile demand production, assembly, logistics Increasing of the vehicle weight body, interior, addit. systems Adaptable and flexible production simulation, crosslinking of fabrication, production adjustment CFC, functional integration Intelligent lightweight construction with the functional integration Affordable diversity for everyone Lighter vehicles with more comfort [source: ARENA2036 LeiFu]
DLR.de slide 4 Active Research Environment Next Generation of Automobiles 2036 Efficient research A new type of cooperation which constantly adapts to new developments The future of the automobile Designing and participation in the fields of Intelligent lightweight design with functional integration (LeiFu) Digital production: new materials and processes (DigitPro) [1] [2] Research factory: production of the future (ForschFab) Creativity, cooperation, transfer of skills (Khoch3) [3] [1] ARENA2036-Leifu (Daimler); [2] ARENA2036-DigitPro; [3] ARENA2036-ForschFab
DLR.de slide 5 Campus in Stuttgart-Vaihingen Neubau eines Projektgebäudes mit großem Potenzial Campus Pfaffenwaldring Campus Allmandring Set up of a new building on the Vaihingen University campus Fast access to the motorway and public transport and linked to the nearby industry Completion at the end of 2016 Offices, laboratories and production areas under one roof Total project area of up to 7,000 sq m Up to 160 new places of work Investment volume approximately 30 MM [source: ARENA2036 LeiFu]
DLR.de slide 6 Intelligent lightweight design with functional integration (LeiFu) - Motivation and project goals [1] [1] Motivation: Reversing the weight spiral through reduction of structural weight Increasing importance of fiber reinforced plastics Approach: FRP-Design with integrated functions Functional integration leads to weight reduction Functional integration leads to lower costs [1] ARENA2036-Leifu Daimler
DLR.de slide 7 Intelligent lightweight design with functional integration (LeiFu) State of the Art Modern vehicle underbody from the series: seperation of functions Predominant separation of the primary structure and functional components [image source: DLR-FK]
DLR.de slide 8 Functional Integration in Composites System levels [4] [4] [5] Fibers sensory fibres Heating wires Textiles Hybrid textiles Load path specific textile reinforcements Combination of Material (e.g. Sandwich cores) foams foldcore Component Geometry ducts, media-carrying lines Component casings, liquid containers Subsystems Battery module, inductive charger unit Fuel tank [4] Institute of Textile Technology and Process Engineering (ITV) Denkendorf ; [5] Institute of Aircraft Design, University of Stuttgart
DLR.de slide 9 Fibers Hybrid textiles Combination of Materials Component Geometry Subsystems [6] Application in critical areas (highly loaded /stressed) for relevant loading situations Composite failure index Functionalized fibers: Sensoric functions (PVDF-fibers): detection of critical loads Mechanical optimized fibers (surface modified): Improvement of interlaminar shear strength in relevant areas of up to 20 % compared to basic sizing [6] [6] ITCF Denkendorf, Germany
DLR.de slide 10 Fibers Hybrid textiles Combination of Materials Component Geometry Subsystems Hybridization of structures Hybridization of laminates Hybridization of textiles [4] [7] e.g.: braided steel profiles [8] e.g.: metallic layers in cfrp-laminate e.g.: integration of metallic wires Hybrid textiles: e.g. hybridization with metallic filaments Improvement in crash performance and structural integrity Additional functionality for chassis ground or EMC-shielding [7] DLR-FK, DLR-BT, FhG ICT, IFB, iwk I: HyTräS ; [8] DLR-BT, 2011; [4] ITV Denkendorf, 2014
DLR.de slide 11 Fibers Hybrid textiles Combination of Materials Component Geometry Subsystems Sandwich-Design (e.g. foam core) Integrated thermal isolation Improved overall vehicle stiffness Improved NVH (global / local) Improved crash stability Geometric installation space for further components/functions Normierte Teilflächenresonanz (%) 400 350 300 250 200 150 100 50 0 Generic area resonance for equal masses
DLR.de slide 12 Fibers Hybrid textiles Combination of Materials Component Geometry Subsystems source: Daimler AG source: DLR Geometrical integration: sandwich-design creates package space for components and functions compatibility of functional interfaces with existing geometry e.g. air ducts: use of rear seat crossmember and reinforcing profiles
DLR.de slide 13 Fibers Hybrid textiles Combination of Materials Component Geometry Subsystems source: DLR Integrated Subsystems: e.g. fuel tank, battery module Fully or partially integrated subsystems Shifting non-structural masses towards load-bearing masses and use of novel load paths e.g. fuel tank integration weight saving ca.10% with constant torsional and bending stiffness
DLR.de slide 14 Overall concept development in LeiFu Concept areas Overall concept Requirements (mechanical) design design concept functional integration Floor module concept Stiffness / strength assembly assembly sequence bodywork joining NVH manufacturing production part joining Crash
DLR.de slide 15 CAE Methods preliminary design FE Optimization for design of laminates (Composite Optimization) Static loads: torsion, bending, lowered rear Crash loads: static equivalent loads (front, side and rear crash) Rear, 100%, rigid barrier, 50km/h 0 90 source: Daimler + DLR Side: pole, 32km/h Front: 100%, rigid barrier, 56km/h Front: 40%, def. barrier 64km/h Front: 25%, rigid barrier 64km/h 1. Definition of load cases ±45 2. Identification of anisotropy 3. Definition of subpreforms and dimensioning
DLR.de slide 16 Simulative verification on equivalent load case pole crash Simulation on floor module segment: central tunnel to rocker panel area of seat cross members clamped in fixed frame construction Intrusion of Pole in floor segment source: Daimler AG Relative comparison to the reference floor structure and evaluation of the effects of: (a) (b) air ducts and cable ducts optional duct reinforcements NVH reinforcements additional absorber structures (a) (b) (c) (d) (c) (d) source: DLR
DLR.de slide 17 Simulative verification on equivalent load case pole crash NVH reinforcements do not affect the crash performance Integrated air ducts do not affect crash performance Integrated cable duct leads to unacceptably high Intrusion sufficient improvement through cable duct reinforcements Separate absorber structures show no relevant improvement reference intrusion Option 1 NVH-reinforcements Integrated air duct reference Option 2 intrusion NVH-reinforcements Integrated air duct Integrated cable duct (reinforced) [source: Daimler AG]
DLR.de slide 18 Preliminary results weight balance Functional integration in FRP structures mass: - 39% parts: - 50% Examples of functional integration on different levels: [1] Reference LeiFu Reference LeiFu Fibers (e.g. sensory fibers, heating wires) Integrated condition monitoring Integrated heating for battery conditioning Geometrical integration: e.g. air ducts: use of rear seat crossmember and reinforcing channels Integrated fuel tank and partially integrated battery housing Textiles Hybrid textiles (crash / stiffness optimized) Laminated sensory or electrical functions Sandwich-Design (e.g. foam core) Integrated thermal isolation Improved overall vehicle stiffness, Improved NVH (global / local) Geometric installation space for further components/functions [1] ARENA2036-Leifu Daimler
DLR.de slide 19 Conclusion FRP functional integration provides an opportunity to reverse the weight spiral The Research Campus ARENA2036 as a local consortium of science and industry provides a perfect platform for the future topics of lightweight construction and production A major challenge is the transfer of technologies in series production CAE-methods Mechanical performance Geometrical components Outlook Materials and processes Thermal, sensory, electrical Functions Further research on individual technologies Investigation on applicability in the floor module concept Building and testing of a hardware demonstrator until 2018 [4] Joining and assembly [9] [4] ITV Denkendorf [9] L. Klein; P. Middendorf: Novel Integration Concepts For Automotive Sensors In Composite Structures, ANTEC 2015
DLR.de slide 20 Thank you for your attention! Contact: Dipl.-Ing. Sebastian Vohrer DLR Institute of Vehicle Concepts Pfaffenwaldring 38-40 70569 Stuttgart Germany Sebastian.Vohrer@dlr.de www.dlr.de/fk +49 (0) 711 6862-8022 Dipl.-Ing. Gundolf Kopp Head of Research Area Lightweight and Hybrid Design Methods DLR Institute of Vehicle Concepts Pfaffenwaldring 38-40 70569 Stuttgart Germany Gundolf.Kopp@dlr.de www.dlr.de/fk +49 (0) 711 6862-593