vehicle testing and instrumentation for presentation
- 1. ME56021-Vehicle Body & Safety Systems Vehicle Body Testing/Safety
- 2. Introduction Vehicle body testing – purpose – Design for the avoidance of accidents and for the protection of the occupants and pedestrians from serious injury if they are involved in accidents. • Active safety – obtained by optimising braking, ride, road holding, steering and handling • Passive safety – two categories: safety for the occupants and safety for pedestrians struck by the car.
- 3. Pedestrian Safety • For pedestrian safety ideally the front should be a vertical plane surface with reduced stiffness at shoulder and hip level, so that it will do nothing worse than bruise pedestrians if the car strikes them – impractical. • Vehicle body panels, if too soft, the part of the human body involved will crash right through it on to the underlying structure; if too hard, its shock absorption capability will be reduced.
- 4. Pedestrian Safety • The radius of transition from the front panel to the front edge of the bonnet should be large enough to avoid breakage of hip and thigh bones. Also, its height should be such as to ensure that the person struck is rolled over on to the bonnet. • The angle of the windscreen should be steep enough to prevent him from being deflected up over the roof. This is because serious injury could occur if the victim were to strike the hard surface of the road behind, where he might be run over by a following vehicle.
- 6. Pedestrian Safety Active hood safety feature If a frontal pedestrian crash is detected. The hood immediately lifts by a few inches so that the pedestrian’s impact hits a softer, and more movable surface than that of the solid parts beneath the hood, or even the windshield.
- 7. Crash Test • Crash test is a kind of destructive testing undertaken to ensure that standards for safe design with regards to crash compatibility and crashworthiness. • There are multiple kinds of crash tests for vehicle safety undertaken to provide the necessary information and guidance to vehicle owners. • In all physical crash tests, dummies are used to scientifically measure the various forces on occupants and pedestrians. • The data gathered from the dummies is then assessed and scores determined for each respective crash test. • In addition, vehicles are required to be fitted with certain safety assist technologies (SAT)
- 8. Crash Test Standard agencies providing crash test facility 1. Australasian New Car Assessment Program (ANCAP) 2. Auto Review Car Assessment Program (ARCAP) 3. China New Car Assessment Program (C-NCAP) 4. European New Car Assessment Programme (Euro NCAP) 5. Allgemeiner Deutscher Automobil-Club (ADAC) in Germany 6. Japan New Car Assessment Program (JNCAP) 7. Latin New Car Assessment Program (Latin NCAP) in Latin America 8. National Highway Traffic Safety Administration (NHTSA) in the United States, 9. Insurance Institute for Highway Safety (IIHS) in the United States 10. Motor Industry Research Association (MIRA) UK.
- 9. Crash Test Types 1. Frontal Impact Test 2. Side Impact Test 3. Rollover Test 4. Poll Test 5. Pedestrian Test 6. Etc…
- 10. Crash Test Frontal Impact Test • Frontal impacts are test impacts undertaken against a solid concrete wall at a precise speed or an oncoming test vehicle. • an aluminium honeycomb block, is fixed to the face of the concrete barrier against which the car is propelled. • An offset test requires only a portion of the front of the car to impact the barrier. • An offset test is important since impact forces in this kind of test remain the same as those with the frontal impact test but a small portion of the car is necessary to absorb all the force of the impact.
- 11. Crash Test Frontal Impact Test • The function of the honeycomb is to simulate penetration into the front crush zone of a vehicle being struck. • To represent the varying stiffness at different heights of the vehicle that is struck, the density of layers of the honeycomb structure is increased at the heights of the bumper and front edge of the bonnet lid.
- 12. Crash Test Frontal Impact Test (Offset) Procedure for offset test - 40% of the car, on the driver's side, makes contact with a crushable aluminium barrier at 64 km/h. The test car has two adult dummies in the front seat; the rear seat has an 18 month old child dummy and a three year old child dummy, both in appropriate child restraints.
- 13. Crash Test Side Impact Test • Side impact tests as a crash test for vehicle safety are also very important since side impact accidents in vehicles result in a high fatality rate. • This happens because cars usually do not have a significant crumple zone to cushion all the impact forces before the occupant is injured.
- 14. Crash Test Side Impact Test A 950kg trolley is run into the driver's side of the test car at 50 km/h. The trolley has a crushable aluminium face to simulate the front of another car.
- 15. Crash Test Rollover Test • A rollover test verifies the car’s ability to support itself, especially from the pillars supporting the roof, during a dynamic impact. • Roadside hardware crash tests ensure that crash barriers and crash cushions protect the passengers of the vehicle from roadside hazards. • This kind of crash test also makes sure that some appurtenances such as sign posts, guard rails, light poles may not serve as a hazard to vehicle occupants.
- 16. Crash Test Pole Test • The pole test simulates an accident in which a car collides with a fixed object such as a tree or pole. Curtain airbags are particularly effective in preventing injury in this type of crash.
- 17. Crash Test Pole Test • A car is propelled sideways at 29 km/h into a rigid pole aligned with the driver's head. The pole is relatively narrow, resulting in major penetration into the side of the car.
- 18. Crash Test Pedestrian test • The pedestrian impact test simulates accidents in which a pedestrian is hit by an oncoming vehicle. These accidents represent about 15% of fatal crashes in Australia and New Zealand.
- 19. Crash Test Pedestrian test • The pedestrian impact test is used to estimate head and leg injuries to child and adult pedestrians struck by a test vehicle at 40km/h.
- 20. Crash Test Whiplash test • Whiplash injuries, associated with rapid and excessive distortion of the spine, can be long-lasting, difficult to diagnose or treat and extremely debilitating. They are also common, most often occurring in low-speed, rear-end collisions. While such crashes rarely result in fatalities, the consequences of whiplash injuries have a huge impact on individuals
- 21. Crash Test Whiplash test • Seats and head restraints are tested on a sled using a low speed rear-impact dummy. Three dynamic tests are done, representing common accident severities known to cause injuries, together with an assessment of the geometry of the front and rear head restraints.