Crash Test Dummies - A Smashing history (BBC4)
crash test dummies are test devices anthropometric full scale ATD that simulate the dimensions, the proportions by weight and the articulation of the human body, and are generally instrumented for recording data on the dynamic behavior of DAE impacts vehicles simulated This data may include variables such as impact velocity, the bending of the crushing force, bending, or torque of the body and deceleration in a collision for use in crash tests They remain essential in the development and usability in all types of vehicles, cars to airplanes.
On August 31, 1869 Mary Ward became what is believed to be the first recorded victim of a steam-powered automobile accident only Karl Benz invented the automobile gasoline as we know, in 1886, Mary Ward was thrown out of a vehicle and killed in Parsonstown, Ireland a few years later, September 13, 1899 Henry Bliss entered the history books as the first fatal accident of north American motor vehicle when it was hit landing a cart New York City Since then, over 20 million people worldwide have lost their lives in motor vehicle accidents.
The need for a way to analyze and mitigate the effects of motor vehicle accidents on the human body was found shortly after the car commercial production began in the 1890s and 1930s, with the automobile part of everyday life, deaths from motor vehicle became a serious issue mortality rate had exceeded 15 6 deaths per 100 million vehicle miles and continued to climb; vehicle designers saw this as a clear indication that it was time to do some research on ways to make their products safer.
In 1930, the interior of a car was not a safe place, even in a low speed collision dashboards were made in rigid metal, steering columns were non-collapsible, and protruding knobs, buttons and levers are ubiquitous seatbelts are unprecedented and in a frontal collision, passengers hurled through the windshield stood very little chance of avoiding serious injury or death to the vehicle body forces himself same was rigid and impact were transmitted directly to the vehicle occupants until the 1950s, automakers were public record as saying vehicle accidents simply could not be made survivable; the forces in a crash were too big and too fragile human body.
Wayne State University in Detroit was the first to begin seriously working on collecting data on the effects of high-speed collisions on the human body in the 1930s, there was no reliable data on the response of the body human to extreme physical injuries, and no effective tools exist to measure these responses Biomechanics was a field barely in its infancy it was necessary to use two types of test subjects in order to develop initial data sets.
The first test subjects were human cadavers They were used to obtain fundamental information about the ability of the human body to resist crushing and tearing generally experienced forces in a high speed accident at such end bearings with steel balls were dropped on skulls and bodies were dumped in unused elevator shafts onto steel plates Cadavers fitted with crude accelerometers were strapped into automobiles and subjected to head-on collisions and rollovers vehicles.
Albert King 1995 Journal of Trauma article, Humanitarian Benefits of Cadaver Research on Injury Prevention, clearly shows the value of lives saved through cadaveric King Research calculations indicate that because of the design changes implemented until 1987, the cadaver research has since saved 8500 lives a year, he notes that for every cadaver used, each year 61 people survive due to wearing seat belts, 147 live due to air bags and 68 survive impact windshield.
However, work with cadavers presented almost as many problems are solved not only there were moral and ethical issues related to working with the dead, but there were also research concerns the majority of cadavers available were older American European adults who are not violent deaths dead; they do not represent a demographic section of accident victims Deceased accident victims can not be employed because any data that could be collected from such experimental subjects would be compromised by previous injuries cadaveric As two bodies are the same, and since any specific part of a cadaver could only be used once, it was extremely difficult to obtain reliable comparative data and more, children's bodies are not only difficult to obtain, but both legal and public opinion actually rendered unusable again, as crash testing became more routine, have become increasingly rare appropriate bodies accordingly, biometric data were limited in extent and skewed toward men older whites.
Some researchers have over themselves to serve as crash test dummies Colonel John Paul Stapp USAF propels more than 1000 km h on a rocket sled and stopped in 1 four seconds Lawrence Patrick, then a professor at Wayne State University , endured some 400 rides on a sled to rocket to test the effects of rapid deceleration on the human body He and his students left themselves smashed in the chest with rockers heavy metals, hit in the face by rotary control hammers tire and sprayed with shattered glass to simulate window implosion while admitting it made him a little, Patrick said the research he and his students conducted was crucial in the development of mathematical models against which further research could be compared But while the live test data was valuable, human subjects could not withstand tests that s have gone beyond a certain degree of physical injury to gather information on the causes and prevention of injuries and deaths woul d require some sort of different subject.
In the mid-1950s, most of the information cadaver testing could provide had been harvested It was also necessary to collect data on the survival chances of accidents, research whose bodies were very inadequate Together with shortages cadavers, this need forced researchers to seek other models description by Mary Roach of Stapp eighth Car crash demonstration Conference and field indicates the direction in which the search began to move we have seen sleds riding chimpanzees rocket, a bear on an impact swing We observed an anesthetized pig and placed in sitting position on the swing in the harness, crashed in a flying plate deep direction at about 10 mph.
One of the major research goals that could be achieved with either dead or living human was a way to reduce the damage caused by impalement on the steering column In 1964, more than one million deaths resulting from impact of flying was recorded, a significant percentage of all deaths; the introduction by General Motors in the early 1960s of the collapsible steering column cut the risk of death at the wheel of fifty percent animal subjects most commonly used in cabin-collision studies were pigs, primarily because their internal structure is similar to a human's pigs can also be placed in a vehicle in a good approximation of a seated man.
The ability to sit upright was an important requirement for test animals to another common fatal injury among human victims, decapitation, could be studied further, it is important that researchers are able to determine how extent cabin design needed to be modified to ensure optimum conditions for survival, for example, a dashboard with too little padding or padding which was too stiff or too soft will not significantly reduce head injury on a dashboard without padding at all Although the buttons, levers and buttons are essential in the operation of a vehicle, which design modifications would best ensure that these elements do not tear or victims puncture in a mirror impact crash rear view is a major event in a frontal collision; How built a mirror so that it is both rigid enough to perform its task and still hit low risk of injury.
While work with cadavers had aroused some opposition, primarily from religious institutions, it was grudgingly accepted because the dead are dead, felt no pain, and indignity of their situation was directly related to pain relief research on animals, on the other hand, aroused much passion groups such as the ASPCA were vehement in their protest animal rights, and while researchers such as Patrick supported experimentation animal because of its ability to produce reliable and applicable data, there was still a strong ethical unease about this process.
Although animal test data were more easily obtained the data from cadavers, that animals are not people and the difficulty of employing adequate internal instrumentation limited their usefulness is not Animal testing more practiced by one of the leading automobile manufacturers; General Motors discontinued in 1993 live tests and other manufacturers have followed suit soon after.
The information gathered from research studies and animal cadavers had been put to use in human simulacra built in 1949, while the Sierra Sam was created by Samuel W Alderson at his Alderson Research Labs ARL and Sierra Engineering Co. to test aircraft ejection seats and pilot restraint harness These tests involved the use of a strong acceleration to 1000 km h 600 mph rocket sled, beyond the ability of volunteers to tolerate in the early 1950s, Alderson and Grumman produced a dummy which was used to conduct crash tests in both motor vehicles and aircraft.
models of mass production gave their use in many other applications.
Alderson went on to produce what he called the VIP-50 series, built specifically for General Motors and Ford, but which has also been adopted by the National Bureau of Standards Sierra followed with a competitor dummy, a model it called Sierra Stan, but GM, who had taken the momentum in the development of a reliable and durable dummy, found neither model satisfied its needs GM engineers decided to combine the best features of the VIP series and Sierra Stan, and so in hybrid in 1971 I was born hybrid I was what is known as a man of the 50th dummy percentile that is to say, it modeled an average man in height, mass, and the proportion of the original Sierra Sam was a man of the 95th model heavier and larger than 95 human men in collaboration with the Society of automotive Engineers SAE, GM shared this design, and a female mannequin after 5th percentile, with himself s competitors.
Since then, considerable work has gone into the creation of more and more sophisticated dummies Hybrid II was introduced in 1972, with improved shoulder, spine and knee responses, and more rigorous documentation Hybrid II became the first model to comply with Federal motor Vehicle safety standard FMVSS US for automotive round testing and shoulder in 1973, a male model 50th percentile was released, and the national administration of road transport safety NHTSA NHTSA has undertaken an agreement with General Motors to produce a superior model to the hybrid II performance in a number of specific areas.
Even if a large improvement over the bodies for the purpose of standardized tests, hybrid and hybrid I II was still very raw, and their use has been limited to the development and test designs seatbelt A dummy was needed, this would allow researchers to explore strategies to reduce injury It was this need that pushed GM researchers to develop the current hybrid line, the hybrid III family of crash test dummies.
The 50th percentile male Hybrid III originally extended family to include a 95th percentile male, 5th percentile female and ten, six and three years old child dummies.
Hybrid III dummy the 50th percentile man who made his first appearance in 1976, is the familiar crash test dummy, and is now a family man if he could stand, he would be 168 cm 5 and 6 speakers would have a mass of 77 kg 170 lbs occupies the driver's seat in all the insurance Institute for Highway safety IIHS 65 km h 40 mph offset frontal crash test, it is joined by a bigger brother, the 95th percentile Hybrid III, 188 cm 6 feet 2 inches and 100 kg 223 lb Ms. Hybrid III dummy is a 5th percentile woman, a diminutive 152 cm 5 feet tall and 50 kg 110 lbs The three models of children Hybrid III represent a decade , 21 kg of 47 pounds six years, and 15 kg 33 lb-three children models are very recent additions to the family of crash test dummy; because little data are available on the consequences of accidents on children and these data are difficult to obtain, these models are based largely on estimates and approximations The main advantage provided by Hybrid III is an improved neck response forward bending and rotation of the head that simulates better humans.
Each Hybrid III undergoes calibration prior to a crash test Headless from 40 centimeters to test calibrate instrumentation of the head and the head and neck are reattached, set in motion, and stopped abruptly to check flexure good neck Hybrids wear chamois leather skin; knees are hit with a metal probe to verify the proper perforation Finally, head and neck are mounted on the body, which is fixed to a platform test and violently strikes the chest by a heavy pendulum to make so that the ribs bend and flex as they should.
When the model was determined to be ready for testing, it is dressed entirely in yellow, marking paint is applied to the head and knees, and calibration marks are fastened to the side of the head to help researchers when the films idling are reviewed later the model is then placed inside the test vehicle Forty-four data channels located in all parts of the hybrid III, from the head of the anchor , record from 30 000 to 35 000 data items in a typical accident 100 150 milliseconds location in a temporary repository in the chest skin, these data are downloaded to the computer once the test is completed.
Because the hybrid is a standardized data collection device, a portion of a particular hybrid type is interchangeable with any other not only a dummy be tested several times, but if a part fails, it can be replaced by a new part A grating integral instrumented manikin is approximately 150,000.
III hybrids are designed to study the effects of frontal impacts, and are less useful in assessing the effects of other types of impacts, such as side impacts, rear impacts or rollovers after frontal collisions, the most common accident injury is the side impact.
Family side impact dummy SID test models has been designed to measure the side, the spine, and the effects of internal organs during side collisions It also evaluates the deceleration of the spine and ribs and compression of the chest cavity SID is the US government standard, EuroSID is used in europe to ensure compliance with safety standards and SID II s is a 5th percentile female BioSID is a more sophisticated version of SID and EuroSID but it is not used in a regulatory capacity WorldSID is a project to develop a new generation of model under the international Standards Organization.
BioRID is a model designed to evaluate the effects of a shock rear Its main objective is to research Whiplash, and to help designers to develop effective head and neck restraints BioRID is more sophisticated in its construction that hybrid spine; 24 vertebra simulators allow BioRID take a much more natural posture sitting, and highlight the neck movement and configuration seen in a rear collision.
THOR offers sophisticated tools for assessing frontal impacts.
CRABI is a child model used to assess the effectiveness of child restraint systems, including seat belts and air bags There are three models of CRABI, representing 18 months, 12 months and children aged 6 month.
THOR is a man of the 50th percentile dummy advanced successor of Hybrid III, THOR has a more humanlike spine and pelvis, and his face has a number of sensors for the analysis of facial impacts with a current accuracy not possible with other models of the sensors THOR range is also superior in quantity and sensitivity than those of Hybrid III.
Further development is needed on mannequins that can address the concern that even if fewer lives are lost, there is still a hundred seriously injured passengers each death and disabling injuries to legs and feet represent a great percentage of physical impairments that result.
An important sector of the traveling public must still be represented in traditional crash tests of pregnant women The first test dummy shock enclosure prototype was built by engineering researchers at Loughborough University in the UK in order improve safety belt design It has a container filled with fluid above the basin to reproduce the fetus and uterus belts may be uncomfortable for pregnant women if some choose not to wear them, reducing their security at a time when it should be increased a second pregnant crash test dummy was designed by a student at the University of Idaho.
Crash test dummies have provided invaluable data on how human bodies react in accidents and have greatly contributed to improving vehicle design While they have saved millions of lives, like cadavers and animals, they reached a reduced data return point.
The biggest problem with acquiring data from cadavers, other than their availability, was an essential element of standardized tests, reproducibility, could not matter how many items could be reused from a previous test, the corpse had to be different each time While modern test dummies have overcome this problem, testers still face essentially the same problem regarding the test vehicle a vehicle crashed only once; no matter how carefully the test is done, it can not be repeated exactly.
A second problem with models is that they are and will never be about human Forty-four data channels on a Hybrid III is not even a remote representation of the number of data channels in a living person of Mimicry internal organs is crude at best, which means that even if the animals and the corpses are not the main source of data on accidents, they should still be used in the study of soft tissue injuries.
The future of crash testing began in the same place it all started Wayne State University King H Yang is one of Wayne State researchers involved in the creation of detailed computer models of human systems Currently, researchers at Wayne State n have not enough or fast computers skilled programmer s to create simulations of the whole body, but the analysis of injuries of body individual systems begins to produce reliable and encouraging results.
The advantage of the computer is that it is not bound by the physical law A virtual vehicle crashed once can be uncrashed then crushed a slightly different way again to be uninterrupted virtual A broken back, the seat belt configuration has changed, and re-broken back when every variable is controllable and reproducible each event, the need for physical testing is significantly reduced.
In the early 21st century, legal certification of new car models is still needed to make using physical dummies in physical vehicles The next generation of crash test dummies can perform their tasks entirely on a computer screen.
Crash test dummy, crash test dummy.