Virtual human body model for fast safety assessment

Transcription

1 Virtual human body model for fast safety assessment Luděk Hynčík et al. Luděk Kovář el al. University of West Bohemia MECAS ESI s.r.o. Plzeň (Pilsen), Czech Republic AUTOSYMPO October 2 November 2017, Roztoky u Prahy (Czech Republic)

2 VIRTUAL HUMAN MODELS Lumped mass based on MBS Rigid bodies connected via joints Easy manipulation, fast computation Over-simplistic Deformable based on FEM Fully deformable body (parts) Biofidelity, predictability (injury criteria) Computational cost, difficult to position Hybrid approach coupling MBS to FEM Scaling and personalization

3 VIRTHUMAN MBS with compressible segments Simple positioning Multi-purpose validation Age scaling

4 REFERENCE MODEL Reference model Virthuman European database CAESAR (close to Hybrid III a Eurosid II) Fully validated (SAE Technical Papers) , DOI: / , DOI: / , DOI: / Scaling for age, gender, height and mass Personalization in preparation

5 VALIDATION Segment Impact direction Impactor description Impact velocity or g level Head Downwards Sphere, kg, Ø 96 mm 7.1 m/s Neck Frontal, Lateral - 15 g and 7 g Frontal Cylinder, 23.4 kg, Ø 150 mm 4.9 m/s, 6.7 m/s and 9.9 m/s Thorax Abdomen Lateral Cylinder, 23.4 kg 4.3 m/s Lateral, Oblique Cylinder, kg 2.5 m/s Frontal Belt, 22 kg and 76 kg 2.9 m/s and 7.8 m/s Frontal Bar, Ø 25 mm, 32 kg 6.1 m/s Belt Force functions Pelvis Lateral Plate, 23.4 kg, 100 x 200 mm 3.46 m/s and 6.66 m/s Knee Lateral (bending and shearing) Block, 6.25 kg 5.56 m/s and m/s Femur Frontal Cylinder, 10.1 kg 13.2 m/s Tibia Lateral-medial Bar, 32 kg 3.55 m/s Fullscale Sled test frontal Sled 30 km/h Pedestrian lateral Vehicle 40 km/h

6 VALIDATION Thorax stiffness Head acceleration T1 acceleration 4,9 m/s Shoulder belt force 6,7 m/s Femur force T1 acceleration

7 PERSONALIZED VALIDATION Dimension Cadavers Scaled models Difference [%] M13 F47 M45 M13 F47 M45 M13 F47 M45 Buttocks-shoulder (9*) [cm] Sitting height (10*) [cm] Pelvis-heel (13*) [cm]

8 Head acceleration x [g] Head acceleration magnitude [g] Lap belt force [kn] Sholder belt force [kn] PERSONALIZED VALIDATION Age [years] Height [cm] Percentile Mass [kg] Delta m Exp. Sex Exp. Dat. Exp. Dat. [%] Exp. Dat. [kg] H7613DOT Boy Buttocks-shoulder (9) [cm] 60 Sitting ms height (10) [cm] 80 ms Pelvis-heel (13) 100 [cm] ms Exp. Delta Delta Exp. Dat. Exp. Dat. Delta [%] Exp. Dat. [%] [%] H7613DOT % % % Experiment H7613DOT Time [ms] Experiment H7613DOT Time [ms] Experiment H7613DOT Time [ms] Experiment H7613DOT HIC36 E = 429 HIC36 V = Time [ms]

9 Displacement [mm] Displacement [mm] F [kn] VULNERABLE ROAD USERS Complex kinematics Courtesy of Karel Abraham Multi-directional loading Neck Lateral and vertical Shoulder loading Side impact Neck lateral impact displacement x Neck lateral impact displacement z Shoulder side impact compression Lower corridor Upper corridor Virthuman Lower corridor Upper corridor Original neck Modified neck t [ms] Lower corridor Upper corridor Original neck Modified neck t [ms] t [ms]

10 VULNERABLE ROAD USERS Kerrigan test at 40 km/h Mid-stance gait, tied hands 60 ms 80 ms 100 ms WAD [mm] THS [ms] Kerrigan 2310* 145* VIRTHUMAN Polar-II 1947* 128* *Average values

11 VULNERABLE ROAD USERS Based on Moto GP accident in Jerez, Spain (2014), 86 km/h Karel Abraham, 24 years, 182 cm, 75 kg Personal protective equipment (PPE) Helmet, added mass representing gloves and boots

12 VULNERABLE ROAD USERS Comparison to THUMS (Ghajari, 2013) VH scaled to 175 cm, 77kg Impact velocity Contact force Head acceleration v n [m/s] v t [m/s] F n,max [kn] F t,max [kn] F t,max / F n,max [-] a max [g] VH THUMS VH THUMS VH THUMS VH THUMS

13 DEMONSTRATION: BARRIER Several national standards and test protocols (F, D, IT, ES) European Technical Specification (TS) CEN TS ATD lying on back impacting by 60 km/h at 30 o Motorcyclist protective clothing and helmet Head and neck performance monitored Critical values of HIC and neck moments (levels I and II)

14 DEMONSTRATION: ASSESSMENT Fictitious un-safe s assessment HIC = 2420 Rigid Thin HIC = 2420 Thick HIC = 2447

15 DEMONSTRATION: ASSESSMENT Segment Criterion Severity level Limit Rigid Thin Thick I 650 Head HIC 16 II 1000 I Shear II I Tension II I Compression II Neck I 134 Nm Lateral flexion II 134 Nm I 42 Nm Extension II 57 Nm I 190 Nm Flexion II 190 Nm Next slides

16 DEMONSTRATION: RISK CURVES Head acceleration resultant curve (including HIC area) Rigid Thin Thick Neck shear force versus time risk curve Rigid Thin Thick

17 DEMONSTRATION: RISK CURVES Neck axial tension force versus time risk curve Rigid Thin Thick Neck axial compression versus time risk curve Rigid Thin Thick

18 FURTHER APPLICATIONS Road transport Vulnerable road user (VRU) Pedestrian, two-wheelers Public transport Air transport Cooperation with WUT

19 CONCLUSION Virtual prototyping addressing safe transport Multi-body approach Local model deformability Contact modelling Initial verification to be done Verified scalable human body model Huge potential for injury prevention Finite element models of vehicles, personal protective equipment and infrastructure Safety equipment development Vehicles and infrastructure design optimization

20 ACKNOWLEDGMENT TA Scalable human models for increasing traffic safety TA Development of Vehicle Active Bonnet System Regarding Variability of Population and Implementing Biomechanical Model Human Body MOTORIST Motorcycle Rider Integrated Safety COST TU1407 Scientific and technical innovations for safer Powered Two Wheelers INTER-COST LTC17001 Exploitation of virtual human model for reducing injury risk of PTW riders Assoc. Prof. Luděk Hynčík, Ph.D. phone: University of West Bohemia Univerzitní 8, Plzeň Czech Republic, Europe URL: