Recently, novel material concepts for high-performance carbon fiber–reinforced composites with active stiffness control were presented in the literature. Although this new class of intelligent, smart, and responsive materials has wide application potential, actual design concepts using active stiffness control are still rare. The integration of smart materials into conventional products often requires radically new design concepts. This communication presents an innovative automotive hood design concept, which integrates active stiffness control composites in order to achieve improved design performance trade-offs in terms of structural weight reduction and vulnerable road user safety. The integration of active stiffness control composites in the hood structure aims to enable active stiffness reduction of the hood or bonnet structure in order to reduce head impact injuries in case of a collision, while satisfying the structural stiffness requirements and lightweight objectives under normal operating conditions. The design concept is investigated using simulation-based evaluation of static, dynamic, and lightweight design criteria. The results are promising, and the presented concept design is a step toward the realization of lightweight smart hood structures for head impact mitigation. Several design features could also be of interest for the integration of active stiffness control composites, in other applications.
AridoganUBasdoganI (2015) A review of active vibration and noise suppression of plate-like structures with piezoelectric transducers. Journal of Intelligent Material Systems and Structures26(12): 1455–1476.
BachingerAMarklundEAndréA, et al. (2015) Materials with variable stiffness. In: ICCM20, 20th international conference on composite materials, Copenhagen, 19–24th July 2015.
4.
BachingerAMarklundERösslerJ, et al. (2014) Stiffness-modifiable composite for pedestrian protection. In: Proceedings of the 16th European conference on composite materials (ECCM), Seville, 22–26 June, 2014.
5.
BalekiDdeMFerreiraAS (2009) Pedestrian concepts with focus on head impact. In: Proceedings SIMEA 09, Sao Paulo, 16 September.
6.
BelingardiGBeyeneATKorichoEG, et al. (2015) Alternative lightweight materials and component manufacturing technologies for vehicle frontal bumper beam. Composite Structures120: 483–495.
7.
BelingardiGChiandussiGGobettoE, et al. (2010) Bonnet weight reduction and VRU protection: design proposals implementing non-conventional materials. International Journal of Automotive Technology11(6): 831–842.
8.
CarreraEValvanoS (2017) Analysis of laminated composite structures with embedded piezoelectric sheets by variable kinematic shell elements. Journal of Intelligent Material Systems and Structures28(20): 2959–2987.
9.
ChopraI (2002) Review of state of art of smart structures and integrated systems. AIAA Journal40(11): 2145–2187.
10.
CostiDTorricelliESplendiL, et al. (2011) Optimization methodology for an automotive hood substructure (Inner panel). In: Proceedings of the world congress on engineering, London, 6–8 July, pp. 6–8. Available at: http://www.iaeng.org/publication/WCE2011/WCE2011_pp2390-2393.pdf
11.
CrandallJRCrandallJR (2002) Designing road vehicles for pedestrian protection. BMJ324(7346): 1145–1148.
12.
CrocettaGPiantiniSPieriniM, et al. (2015) The influence of vehicle front-end design on pedestrian ground impact. Accident Analysis & Prevention79: 56–69.
13.
DollarPWojekCSchieleB, et al. (2012) Pedestrian detection: an evaluation of the state of the art. IEEE Transactions on Pattern Analysis and Machine Intelligence34(4): 743–761.
14.
EdwardsMNathansonAWischM (2014) Estimate of potential benefit for Europe of fitting autonomous emergency braking (AEB) systems for pedestrian protection to passenger cars. Traffic Injury Prevention15(Supp. 1): S173–S182.
Euro NCAP (2015a) Assessment Protocol-Pedestrian Protection (Version 8). Leuven: Euro NCAP.
17.
Euro NCAP (2015b) Pedestrian Testing Protocol. Leuven: Euro NCAP.
18.
FangJGaoYAnX, et al. (2016) Design of transversely-graded foam and wall thickness structures for crashworthiness criteria. Composites Part B: Engineering92: 338–349.
19.
FerreiraADBLNóvoaPROMarquesAT. (2016) Multifunctional material systems: a state-of-the-art review. Composite Structures151: 3–35.
20.
FredrikssonRRosénE (2012) Integrated pedestrian countermeasures—potential of head injury reduction combining passive and active countermeasures. Safety Science50(3): 400–407.
21.
FredrikssonRBoströmOZhangL, et al. (2006) Influence of pop-up hood systems on brain injuries for vulnerable road users. In: Proceedings of international IRCOBI conference on the biomechanics of impact, pp. 253–264. Available at: http://www.ircobi.org/wordpress/downloads/irc0111/2006/Session4/42.pdf
22.
GandhiFKangS-G (2007) Beams with controllable flexural stiffness. Smart Materials and Structures16(4): 1179–1184.
23.
GandhiTTrivediMM (2007) Pedestrian protection systems: issues, survey, and challenges. IEEE Transactions on Intelligent Transportation Systems8(3): 413–430.
24.
GeronimoDLopezAMSappaAD, et al. (2010) Survey of pedestrian detection for advanced driver assistance systems. IEEE Transactions on Pattern Analysis and Machine Intelligence32(7): 1239–1258.
25.
GrubbGZelinskyANilssonL, et al. (2004) 3D vision sensing for improved pedestrian safety. In: IEEE intelligent vehicles symposium, Parma, 14–17 June.
26.
HenkeMGerlachG (2016) A multi-layered variable stiffness device based on smart form closure actuators. Journal of Intelligent Material Systems and Structures27(3): 375–383.
27.
HeuelSRohlingH (2012) Pedestrian classification in automotive radar systems. In:2012 13th international radar symposium. Available at: https://ieeexplore.ieee.org/document/6233285
28.
HuJKlinichKD (2015) Toward designing pedestrian-friendly vehicles. International Journal of Vehicle Safety8(1): 22.
JakobssonLBrobergTKarlssonH, et al. (2013) Pedestrian airbag technology—a production system. In: 23rd international technical conference on the enhanced safety of vehicles (ESV) national highway traffic safety administration, Seoul, South Korea, 27–30 May 2015.
31.
KongCLeeHParkH (2016) Design and manufacturing of automobile hood using natural composite structure. Composites Part B: Engineering91: 18–26.
32.
KrennMMlekuschBWilflingC, et al. (2003) Development and evaluation of a kinematic hood for pedestrian protection. SAE technical paper series. Available at: https://saemobilus.sae.org/content/2003-01-0897
33.
KrishnamoorthyRTaklaMSubicA, et al. (2015) Optimization of hood design to minimise pedestrian head injury in impact. In: DaiLJazarRN (eds) Nonlinear Approaches in Engineering Applications. Berlin: Springer, pp. 161–218.
34.
LiuQLinYZongZ, et al. (2013) Lightweight design of carbon twill weave fabric composite body structure for electric vehicle. Composite Structures97: 231–238.
35.
LiuZLuJZhuP (2016) Lightweight design of automotive composite bumper system using modified particle swarm optimizer. Composite Structures140: 630–643.
36.
MaplesHAWakefieldSRobinsonP, et al. (2014) High performance carbon fibre reinforced epoxy composites with controllable stiffness. Composites Science and Technology105: 134–143.
37.
MukhtarAXiaLTangTB (2015) Vehicle detection techniques for collision avoidance systems: a review. IEEE Transactions on Intelligent Transportation Systems16(5): 2318–2338.
NasirMAAkramHKhanZM, et al. (2015) Smart sensing layer for the detection of damage due to defects in a laminated composite structure. Journal of Intelligent Material Systems and Structures26(17): 2362–2368.
40.
ParkGParkH (2018) Structural design and test of automobile bonnet with natural flax composite through impact damage analysis. Composite Structures184: 800–806.
41.
RivasEBarberoE (2016) Stiffness control in adaptive thin-walled laminate composite beams. Composites Part A: Applied Science and Manufacturing80: 118–126.
42.
SalaRBaldanziniNPieriniM (2017) SQG-differential evolution for difficult optimization problems under a tight function evaluation budget. In: NicosiaGPardalosPGiuffridaG, et al. (eds) International Workshop on Machine Learning, Optimization, and Big Data. Berlin: Springer, pp. 322–336.
43.
SassiSSassiACherifK, et al. (2018) Magnetorheological damper with external excitation for more efficient control of vehicles’ dynamics. Journal of Intelligent Material Systems and Structures29: 2919–2932.
44.
ShojaeefardMHNajibiAAhmadabadiMR (2014) Pedestrian safety investigation of the new inner structure of the hood to mitigate the impact injury of the head. Thin-Walled Structures77: 77–85.
45.
SpillmanWBSpillmanWBSirkisJS, et al. (1996) Smart materials and structures: what are they?Smart Materials and Structures5(3): 247–254.
46.
StrandrothJRizziMSternlundS, et al. (2011) The correlation between pedestrian injury severity in real-life crashes and Euro NCAP pedestrian test results. Traffic Injury Prevention12(6): 604–613.
47.
TridechCMaplesHARobinsonP, et al. (2013) High performance composites with active stiffness control. ACS Applied Materials & Interfaces5(18): 9111–9119.
48.
US Environmental Protection Agency (USEPA) (2016) Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990-2014. Washington, DC: USEPA.
49.
ValladaresDAlbaJJAltuboI (2017) Energy absorbing composite structure for frontal pedestrian protection in electric light vehicles. Advances in Mechanical Engineering9(2): 1–18.
50.
World Health Organization (WHO) (2011) Burden of Disease from Environmental Noise: Quantification of Healthy Life Years Lost in Europe. Geneva: WHO.
51.
World Health Organization (WHO) (2015) Global Status Report on Road Safety 2015. Geneva: WHO.
52.
World Health Organization (WHO) (2017) Managing Speed (WHO/NMH/NVI/17.7). Geneva: WHO.
53.
WuDChenJ (2012) Development and evaluation of a new active engine hood lifting system. In: QianZCaoLSuW, et al. (eds) Recent Advances in Computer Science and Information Engineering. Berlin: Springer, pp. 239–244.
54.
WuYLiuQFuJ, et al. (2017) Dynamic crash responses of bio-inspired aluminum honeycomb sandwich structures with CFRP panels. Composites Part B: Engineering121: 122–133.
55.
YangH-IYunY-WParkG-J (2015) Design of a pedestrian protection airbag system using experiments. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering230(9): 1182–1195.
56.
YaoJYangJOtteD (2007) Head injuries in child pedestrian accidents—in-depth case analysis and reconstructions. Traffic Injury Prevention8(1): 94–100.
57.
YuenMCBilodeauRAKramerRK (2016) Active variable stiffness fibers for multifunctional robotic fabrics. IEEE Robotics and Automation Letters1(2): 708–715.
