Types of crash test of vehicle
- 1. • Topic : 1. Collision Test : A crash test is a form of destructive testing usually performed in order to ensure safe design standards in crashworthiness and crash compatibility for various modes of transportation (see automobile safety) or related systems and components. Crash testing helps develop safety systems and inform consumers, which takes some of that risk away. While smashing cars into walls or each other may seem wasteful, the data these tests yield is invaluable.
- 2. • Types of collision Test : 1. Frontal-impact test : Vehicles usually impact a solid concrete wall at a specified speed, but these can also be vehicle impacting vehicle tests. 2. Moderate Overlap tests : In which only part of the front of the car impacts with a barrier (vehicle). These Are important, as impact forces(approximately) remain the same as with a frontal impact test, but a smaller Fraction of the car is required to absorb all of the force
- 3. 3. Small Overlap tests : This is where only a small portion of the car’s structure strikes an object such as a pole Or a tree, or if a car were to clip another car.
- 4. 4. Side-impact : These forms of accidents have a very significant likelihood of fatality, as cars do not Have a significant crumple zone to absorb the impact forces before an occupant is injured.
- 5. 1. NVH Test : Noise, vibration, and harshness (NVH), also known as noise and vibration (N&V), is the study and Modification of the noise and vibration characteristics of vehicles, particularly cars and trucks. While noise and Vibration can be readily measured, harshness is a subjective quality, and is measured either via “jury” evaluations, Or with analytical tools that can provide results reflecting human subjective impressions. In some cases the NVH engineer is asked to change the sound quality, by adding or subtracting particular Harmonics, rather than making the vehicle quieter.
- 6. • Tools/Instruments : Typical instrumentation used to measure NVH include microphones, accelerometers and force gauges, or load Cells. Many NVH facilities will have semi-anechoic chambers, and rolling road dynamometers. Typically signals Are recorded direct to hard disk via an analogy-to-digital converter. In the past magnetic or DAT tape recorders Were used. The integrity of the signal chain is very important, typically each of the instruments used are fully Calibrated in a lab once per year, and any given setup is calibrated as a whole once per day.
- 8. 3.Roll Over Test : A rollover is a type of vehicle crash in which a vehicle tips over onto its side or roof. Rollovers have a Higher fatality rate than other types of vehicle collisions. Vehicle rollovers are divided into two categories: tripped and unstripped. Tripped rollovers are caused by Forces from an external object, such as a curb or a collision with another vehicle. Unstripped crashes are the result Of steering input, speed, and friction with the ground.
- 9. • The most common type of tripped rollover occurs when a vehicle is sliding sideways, and the tires strike A curb, dig into soft ground, or a similar event occurs that results in a sudden increase in lateral force. The physics Are similar to cornering rollovers. In a 2003 report, this was the most common mechanism, accounting for 71% Of single- vehicle rollovers.
- 10. 4.Wind Tunnel Test : For those of you that don’t already know this, wind tunnel testing were initially aimed at conducting Aerodynamic research mostly involving aircrafts. The first enclosed wind tunnel for aeronautical purposes was Designed and operated in 1871 by Francis Herbert Wenham from the Aeronautical Society of Great Britain, Delivering many fundamental discoveries. However, wind tunnel testing was only applied to automobiles almost One century later, after years of using computer simulations instead of real-life procedures.
- 11. • Types of wind tunnel Testing : 1. Model Scale Testing : Depending on the size of the vehicle and the limitations of the test facility models typically lie between 30% - 60%. Model scale testing is ideal for rapid evaluation of the influence of different body styles and features on the vehicle’s aerodynamics.
- 12. 2. The First : It wasn’t until 1960 that the first dedicated automotive wind tunnel was inaugurated by the specialists at MIRA, opening its doors for vehicle aerodynamics research. Since then, MIRA’s aerodynamicists have been investigating the use of computers to predict the aerodynamic performance of different vehicle shapes initially with in-house developed empirically based codes.
- 13. 3.The Largest : Put into operation in 1980, the GM Aerodynamic Laboratory is the largest wind tunnel in the world dedicated to automotive use (the only bigger tunnels are used by the aerospace industry). This wind tunnel features a 4,500 hp fan that can create winds up to 138 miles per hour.