CAE-Companion-2018-2019

Engineering WISSEN CAE

Functional Development: Pedestrian Protection - Head Impact

Requirements/Critical Target Values: „ „ UN R127: Impactors:

3.5 kg & 4.5 kg (Phase 2) Headform Impactor

Test Conditions & Criteria:

Phase 2

Child/Small Adult

3.5 kg / 35 km/h (9.7 m/s) / 50° BLE/WAD 1000 - WAD 1700 / Bonnet rear edge 4.5 kg / 35 km/h / 65° WAD 1700 - Bonnet rear edge/WAD 2100 < 1000 (1/2 of the Child head impact area AND 2/3 of the total impact area) <1700 (remaining area)

Adult HIC 15

„ „ Euro NCAP: Impactors:

3.5 kg & 4.5 kg Headform Impactor

Test Conditions:

Child/Small Adult 3.5 kg / 40 km/h (11.1 m/s) / 50° BLE/WAD 1000 - WAD 1500 Adult 4.5 kg / 40 km/h (11.1 m/s) / 65° WAD1500 -WAD2100 (if points betweenWAD1500 and1700 areonbonnet, use childhead)

Criteria:

maximum Score

0 Points

HIC 15

< 650

≥ 1700

Procedures: „ „ Use of full vehicle models (impact area: detailed models of all components; engine package can be rigid) „ „ High detailing for bonnet attachments, hinges, locks, sealing structures, bonnet shock damper, head light attachments, windshield wiper assemblies „ „ Connection modeling is highly significant (spot welds, adhesives etc.) „ „ Use of validated material model for windshield failure

„ „ Use of validated impactor model „ „ Typical simulation duration: 20 ms Critical Modelling Parameters: „ „ Strain rate dependency of materials in the impact area „ „ Details of spatial discretization Evaluation Criteria: „ „ Head Injury Criterion (HIC 15 ) „ „ For the optimization: use of acceleration - displacement diagrams to identify jamming Main Influencing Factors:

„ „ Geometry of vehicle front (impact points, impact behavior) „ „ Material stiffness at impact point (potential for optimization) „ „ Stiffness of geometrical package (sheet metal thickness, structural reinforcements in direction of impact, inlays, application of adhesives) „ „ Clearance between bonnet outer shell and package (min. 60 - 80 mm free displacement required, otherwise an active bonnet should be considered) „ „ No jamming elements (e.g. bonnet shock dampers, wiper axles) should be packaged directly in the impact area „ „ Homogenous support of the impactor along the full bonnet/vehicle width is required (e.g. muffin-like structure for the bonnet inner shell). „ „ Sharp stiffness gradient should be avoided.

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