Status of NHTSA’s Roof Crush Research Donald T. Willke National Highway Traffic Safety Administration SAE Government/Industry Meeting May 10, 2004 Roof Crush • Phase 1 – Determine Plate Angles • Phase 2 – Initial Fleet Evaluation • Phase 3 – Expanded Fleet Evaluation Roof Crush Phase 1 - Approach • Computer Simulation to Select Test Conditions – 5° pitch, 25° roll – 10° pitch, 45° roll • Tested 3 Pairs of Vehicles – 1997 Dodge Grand Caravan – 1998 Chevrolet S-10 Pickup – 2002 Ford Explorer • Compared Force vs. Displacements • Compared Damage to Real World Roof Crush Phase 1 - Summary • No Trend in Energy ‘Absorbed’ • No Trend in Peak Force • No Trend in Far-Side Lateral Crush • More Vertical Crush in 5° x 25° • Any Differences Were Very Subtle – Not distinguishable in subjective evaluation of photographs of roof damage Roof Crush Phase 2 - Approach • Test 10 Recent Model Vehicles • Load Plate Angles - 5° pitch, 25° roll • Test to 254 mm of Load Plate Displacement • Collect Force vs. Displacement Data • Collect Headroom Measurement Data Roof Crush Phase 2 - Vehicles: One From Each Type/Size • Passenger Cars: – 2002 Ford Mustang • Pickup Trucks: – 2002 Toyota Camry – 1998 Chevrolet S-10 – 2001 Ford Crown Victoria Pickup* • Sport Utility Vehicles: – 2002 Dodge Ram 1500 – 2002 Honda CR-V Pickup – 2002 Ford Explorer* • Vans: – 2001 Chevrolet Tahoe – 1997 Dodge Grand Caravan* * Data from Phase 1 – 1999 Ford E-150 Econoline Van Roof Crush Phase 2 - Roof Attachment Point • Seat Track Position & Seat Back Angle for 50th Male per FMVSS 208 • Locate H-Point Using OSCAR Device – x and z coordinates • Identify ‘Top of Head’ – Located for first vehicle by seating H-3 dummy – Used translation of OSCAR x and z coordinates for remaining vehicles – y coordinate from centerline of seat • Locate Point Vertically Above ‘Top of Head’ – On interior roof liner – On exterior hard roof Roof Crush Phase 2 300.0 250.0 – Initial Headroom 200.0 150.0 Headroom100.0 (mm) 50.0 0.0 Mustang S-10 PU Camry Explorer Crown Vic Caravan CR-V to roof to brace Ram PU to liner Tahoe E-150 Van Roof Crush Phase 2 – String Potentiometer Attachment 3 string potentiometers were used to track the roof point initially above the drivers head Roof Crush Phase 2 - Results Percent of Vehicle Weight vs. Displacement To 254 mm Load Plate Displacement 1997 Dodge Grand Caravan 1998 Chevrolet S10 Pickup 2002 Ford Explorer 2002 Dodge Ram 1500 Pickup 2002 Toyota Camry 2002 Ford Mustang 2001 Chevrolet Tahoe 2002 Ford Crown Victoria 2002 Honda CRV 1999 Ford E150 Van 350% 300% 250% 200% 150% Percent of Vehicle Weight 100% 50% 0% 0 25 50 75 100 125 150 175 200 225 250 275 Average Displacement (mm) Roof Crush Phase 2 - Maximum Force AchievedResults Within 125 mm External Crush 400 350 300 250 200 150 Percent Vehcile100 Weight (%) 50 0 Mini-Cooper* S-10 PU Mustang Camry Mazda 6* CR-V Caravan Crown Vic Explorer Sorento* Windstar* Ram PU TrailBlazer* Tahoe E-150 Van Roof Crush Phase 2 - Results Percent of Vehicle Weight vs. Headroom Remaining to Roof To 254 mm Load Plate Displacement 1997 Dodge Grand Caravan 1998 Chevrolet S10 Pickup 2002 Ford Explorer 2002 Dodge Ram 1500 Pickup 2002 Toyota Camry 2002 Ford Mustang 2001 Chevrolet Tahoe 2001 Ford Crown Victoria 2002 Honda CRV 1999 Ford E150 Van 350% 300% 250% 200% 150% Percent of Vehicle Weight 100% 50% 0% 260 240 220 200 180 160 140 120 100 80 60 40 20 0 -20 -40 -60 -80 -100 -120 Headroom Remaining (mm) Headroom Remaining at 150% Vehicle Weight 300 250 200 to roof All vehicles reached 150 to liner 150% of vehicle 100 weight with significant 50 Headroom Remaining (mm) head room remaining 0 Camry CR-V * Tahoe S-10 PU Ram PU Mustang Explorer Caravan Crown Vic E-150 Van * to brace Headroom Remaining at 200% Vehicle Weight 200 Only 1 vehicle did not have 180 160 a peak force above 200% of 140 120 to roof vehicle weight, but it still 100 to liner 80 had positive head room at 60 the end of the test 40 20 Headroom Remaining (mm) 0 Camry CR-V * Tahoe S-10 PU Ram PU Mustang Explorer Caravan Crown Vic E-150 Van Headroom Remaining at 250% Vehicle Weight 200 150 100 to roof 8 of the 10 vehicles had a to liner 50 peak force above 250% of 0 vehicle weight, and 6 of Headroom Remaining (mm) these had positive head -50 room remaining Camry CR-V * Tahoe S-10 PU Ram PU Mustang Explorer Caravan Crown Vic E-150 Van * to brace Headroom Remaining at 300% Vehicle Weight 150 4 vehicles had a peak force 100 above 300% of vehicle 50 weight, and 2 of these had to roof to liner positive head room 0 remaining -50 Headroom Remaining (mm) -100 Camry CR-V * Tahoe S-10 PU Ram PU Mustang Explorer Caravan Crown Vic E-150 Van Roof Crush Phase 3 - Approach • Test 10 Recent Model Vehicles • Load Plate Angles - 5° pitch, 25° roll • Test to 254 mm of Load Plate Displacement • Collect Force vs. Displacement Data • Document Time of Liner-to-Head Contact Roof Crush Phase 3 - Vehicles • Passenger Cars: – 2003 Ford Focus • Pickup Trucks: – 2003 Chevrolet Cavalier – 2003 Toyota Tacoma – 2001 Ford Taurus – 2003 Ford F-150 – 2003 Chevrolet Impala • Van: • Sport Utility Vehicles: – 2003 Chevrolet Express – 2003 Subaru Forester (15-passenger) – 2002 Nissan Xterra – 2003 Ford Expedition Roof Crush Phase 3 – Dummy Placement • Hybrid-III 50th Male • Positioned per FMVSS 208 • Arms and Legs Removed • Contact Switch on Head and Liner Roof Crush Phase 3 - Results Percent of Vehicle Weight vs. Displacement To 254 mm Load Plate Displacement Ford Focus Chevrolet Cavalier Ford Taurus Chevrolet Impala Subaru Forester Nissan Xterra Ford Expedition Toyota Tacoma Pickup Ford F-150 Pickup Chevrolet Express Van 500% 450% 400% 350% 300% 250% 200% Percent of Vehicle Weight 150% 100% 50% 0% 0 50 100 150 200 250 300 Displacement (mm) Roof Crush Phase 3 - Results Percent of Vehicle Weight vs. Displacement To Head Contact Ford Focus Chevrolet Cavalier Ford Taurus Chevrolet Impala Subaru Forester Nissan Xterra Ford Expedition Toyota Tacoma Pickup Ford F-150 Pickup Chevrolet Express Van 500% 450% 400% 350% 300% 250% 200% Percent of Vehicle Weight 150% 100% 50% 0% 0 20 40 60 80 100 120 140 160 180 200 Displacement (mm) Roof Crush Phase 3 - Results Maximum Force Prior to Head Contact 500% 450% 400% 350% 300% 250% 200% 150% 100% Percent of Vehicle Weight 50% 0% Focus F-150 Taurus Impala Xterra Cavalier Forester Tacoma Expedition Express Van THE END.