Revision of hen1317-5: Technical improvements

Revision of hen1317-5: Technical improvements Luca Felappi Franz M. Müller Project Leader Road Safety Consultant AC&CS-CRM Group GDTech S.A., Liège Science Park, rue des Chasseurs-Ardennais, 7, B-4031 LIEGE Tél. : +32 4 367 87 11 Fax : +32 4 376 68 22 GDTech France S.A.S. Siège Social : Site Aéropolis F-64510 BORDES Tél. : +33 (0) 5 59 82 35 35 Fax : +33 (0) 5 59 02 08 67 Agence de Paris : 15 avenue Emile Baudot F-91300 MASSY Tél. : +33 1 69 18 81 50 Fax : +33 1 64 46 29 65 -

AFB20(2) Roadside Safety Design Subcommittee on International Research Activities Transportation Research Board of the National Academies (TRB) Bruxelles, Belgium, 11 April 2013 Effects of materials tolerances on design of road safety barriers Claudia COFANO GDTech S.A., Liège Science Park, rue des Chasseurs-Ardennais, 7, B-4031 LIEGE Tél. : +32 4 367 87 11 Fax : +32 4 376 68 22 GDTech France S.A.S. Siège Social : Site Aéropolis F-64510 BORDES Tél. : +33 (0) 5 59 82 35 35 Fax : +33 (0) 5 59 02 08 67 Agence de Paris : 15 avenue Emile Baudot F-91300 MASSY Tél. : +33 1 69 18 81 50 Fax : +33 1 64 46 29 65 -

Introduction European Roads Administrations invest in roadside safety structures more crashworthy Common materials to build road restraints systems: steel and concrete Keywords: high mechanical performances and durability

Materials classification in EU standards Criteria for classification: Physical - chemical properties (e.g. composition) Mechanical properties (e.g. yield strength, tensile strength, compressive strength) Definition of ranges for grade: Minimum values Large tolerances Referenced European standards: EN10025: Hot rolled products of structural steels EN10346: Continuously hot-dip coated steel flat products EN10149: Hot-rolled products made of high yield strength steels for cold forming EN206-1: Concrete

Materials classification in EU standards EN10149 EN10346 EN10025 EN206-1

Materials classification in EU standards EN10149 EN10346 EN10025 Are these tolerances appropriated for EN206-1 crashworthy applications?

Prototypes materials characterization ITT (EN1317-2) Containment Level ASI, THIV Class of WW &VI Construction Manual/FPC (EN1317-5) Material Geometry What about the trend? Using materials with higher resistance than the nominal values Best results Producing on large scale using material of lower resistance Save costs

Prototypes materials characterization: examples EXPERIMENTAL TEST VALUES Barrier Type Mechanical properties Test Value W BEAM POST SPACER Nominal Value* Steel Grade Test Value Nominal Value* Steel Grade Test Value Nominal Value* Steel Grade Sigma Y [N/mm² ] 324 >235 434 >235 304 >235 H4b Side Barrier Failure [N/mm² ] 422 360-510 S235JR 477 360-510 S235JR 371 360-510 S235JR AL [%] 30 >21 30 >21 35 >21 = 199MPa = 89MPa = 69MPa *EN10025-2:2004 European structural steel

Prototypes materials characterization: examples EXPERIMENTAL TEST VALUES Barrier Type Mechanical properties Test Value W BEAM POST SPACER Nominal Value* Steel Grade Test Value Nominal Value* Steel Grade Test Value Nominal Value* Steel Grade Sigma Y [N/mm² ] 359 >235 306 >235 394 >235 H4b Side Barrier Failure [N/mm² ] 416 360-510 S235JR 353 360-510 S235JR 428 360-510 S235JR AL [%] 37 >21 31 >21 36 >21 = 124MPa = 71MPa = 159MPa *EN10025-2:2004 European structural steel

Prototypes materials characterization: examples EXPERIMENTAL TEST VALUES Barrier Type Mechanical properties Test Value W BEAM POST SPACER Nominal Value* Steel Grade Test Value Nominal Value* Steel Grade Test Value Nominal Value* Steel Grade Sigma Y [N/mm² ] 339.67 >235 546.33 >355 338.67 >235 H2 Side Barrier Failure [N/mm² ] 427.00 360-510 S235JR 582.33 470-630 S355JR 394.00 360-510 S235JR AL [%] 36.67 >21 31.67 >22 38.17 >21 = 191MPa = 105MPa = 104MPa *EN10025-2:2004 European structural steel

How material tolerances can affect barrier performance?

Evaluation of barrier performance using FE method Study on N2 side barrier

Evaluation of barrier performance using FE method Effects on Working Width Same steels according to EN10025 are used in the simulation. but Big difference of the working width W [m] 1.10 1.05 1.00 0.95 0.90 0.85 W4 W3 0.80 0.75 0.70 0.65 R 2 = 0.9726 W2 0.60 200 250 300 350 400 450 500 Re [Mpa] Reason: too wide steel grade definition in the standards

Evaluation of barrier performance using FE method Effects on ASI 0.9 0.8 0.7 ASI RT S1b3 - CdG S1b2 - hab S1b4 - CdG S1b7 - CdG 0.6 ASI [g] 0.5 0.4 0.3 0.2 0.1 0-0.08-0.03 0.02 0.07 0.12 0.17 0.22 0.27 0.32 0.37 Time [s] Big difference of the ASI too

Evaluation of barrier performance using FE method Study on H4b side barrier FE Models 900 kg car 38 tons truck H4b Safety Barrier Materials Yield=125 Mpa Strenght=150 MPa Steel Yield stress Ultimate strength S235JR_min 235 MPa 360 MPa S235JR_max 360 MPa 510 MPa Safe-Steel_max 320 MPa 450 MPa Vehicle Intrusion Criteria for Comparison ASI VI

Evaluation of barrier performance using FE method Study on H4b side barrier: Test TB11 S235JR_min S235JR_max SafeSteel_max

Evaluation of barrier performance using FE method Study on H4b side barrier: Test TB11 Results Steel S235JR_min S235JR_max SafeSteel_max ASI (TB11) 1.66 2.12 1.86 S235JR_min S235JR_max SafeSteel_max

Evaluation of barrier performance using FE method Study on H4b side barrier: Test TB81 S235JR_min S235JR_max SafeSteel_max

Evaluation of barrier performance using FE method Study on H4b side barrier: Test TB81 Results Steel S235JR_min S235JR_max SafeSteel_max VI [m] 2.92 (VI8) 2.36 (VI7) 2.64 (VI8) S235JR_min S235JR_max SafeSteel_max

Evaluation of barrier performance using FE method Study on H4b side barrier: Conclusion

How those tolerances can affect barrier development?

Prototypes materials characterization: examples Development of H2 side barrier: Nominal values vs High values W4 Nominal Values for Steel are used WW = 1.475m W5 W5 W4 High Values for Steel are used WW = 1.300m W4 W5

Prototypes materials characterization: examples Study on H2 side barrier: Nominal values vs Actual values EXPERIMENTAL TEST VALUES Barrier Type Mechanical properties Test Value W BEAM POST SPACER Nominal Value* Steel Grade Test Value Nominal Value* Steel Grade Test Value Nominal Value* Steel Grade Sigma Y [N/mm² ] 339.67 >235 546.33 >355 338.67 >235 H2 Side Barrier Failure [N/mm² ] 427.00 360-510 S235JR 582.33 470-630 S355JR 394.00 360-510 S235JR AL [%] 36.67 >21 31.67 >22 38.17 >21 = 191MPa Simulations Nominal WW=1.475m W5 Simulations High WW=1.300m W4 = 105MPa = 104MPa Actual crash test WW=1.3m W4 *EN10025-2:2004 European structural steel

Prototypes materials characterization: examples Study on H2 New Jersey concrete side barrier: Concrete quality modification ASI =1.4 (B) Roll over risk >>

Prototypes materials characterization: examples Study on H2 New Jersey concrete side barrier: Concrete quality modification Eroded Mass ± 35kg

Bad regulation in Belgium for that barrier What has been tested CEM52.5 ~ 42.5MPa What recommend Belgium for the same barrier CEM42.5 ~ 30MPa Why? -Easier to cast -No controls/no CE

Bad regulation in Belgium for that barrier Consequences of the quality modification 42,5MPa (ITT, CEM50) => 30MPa (CME 30) Easier to cast!

H2 New Jersey Barrier: Concrete quality modification Concrete 30MPa

H2 New Jersey Barrier: Concrete quality modification Concrete 30MPa

H2 New Jersey Barrier: Concrete quality modification Concrete 30MPa

H2 New Jersey Barrier: Concrete quality modification Concrete 30MPa

H2 New Jersey Barrier: Concrete quality modification Concrete 30MPa

H2 New Jersey Barrier: Concrete quality modification Concrete 30MPa

H2 New Jersey Barrier: Concrete quality modification Concrete 30MPa

H2 New Jersey Barrier: Concrete quality modification Concrete Nominal Value Eroded Mass = 35kg Concrete 30 MPa Eroded Mass = 330kg Damages increase + High risk to decrease the containment level

Conclusions Material tolerances may affect road devices performances Possible consequences on road application might be: Change of deformation class Potential loss of restraint capacity Increase of severity indices Important differences between the prototype tested and the installed system Need of an effective solution to protect of vehicle occupants and prevent serious injury in case of vehicles impacting a restraint device

Thank you for your attention! Questions?

Revision of hen1317-5: Technical improvements Luca Felappi Franz M. Müller Project Leader Road Safety Consultant AC&CS-CRM Group