Реферат на тему Crash Test Dummies Essay Research Paper Crash
Crash Test Dummies Essay, Research Paper
Crash Test Dummies
Crash test dummies are very important in vehicle safety. Without them the death rate in car accidents would be higher. Dummies are used so human lives can be saved. Crash test dummies have been greatly developed over the years, they are put through many tests and these tests need to be done to help improve automobiles.
First of all, the development of todays crash test dummies has required a lot of work. In 1949, the Sierra Sam was first made. It was a 95th percentile adult male dummy. It was used by the United States Air Force to test aircraft ejection seats. It had a humanlike exterior shape, body weight and some limb joints. The spine and neck designs had very little resemblance to humans. Mark I, created in 1952, was also a 95th percentile male. It was used by the U.S. and European Air Forces. This new design was similar to humans only in shape, size and total weight. The elbows, wrists, knees and ankles were one piece limbs which caused them to be too stiff to provide accurate data. As a result, only a few models were produced. Other dummy models, the F,B & P general purpose dummies, were produced in 1953 and was available in eight different sizes. It had a better design than previous models, and it provided better responses. This dummy was used for many purposes. It was used in the project Apollo Landing Testing, underwater escape tests, tractor-safety programs and many other automotive and aircraft programs. The use of this dummy was discontinued in the late 1960s. The Gard Dummy was developed in the 1960s and eight different sizes were made. It was used in testing aircraft ejection seats and in Navy programs. This design is still used in some tests today. The development of the VIP (Very Important People) model dummy started in 1966. Until this time, crash dummies were made to meet the standards of aircrafts. Previous dummies did not meet the needs for automobile testing. For example the dummies didnt have a pelvic structure and the spine was not humanlike. The VIP model dummy was made to be more like a human and to provide more accurate and helpful information in automotive testing. The very first standard automotive crash test dummies were the VIP-50A. It was completed and shipped in early 1968. Research in making the Sierra Stan, another dummy produced to meet the needs of the automotive industry, started in 1967. It was an adult, 50th percentile male dummy. In making changes to the VIP-50A, the VIP95 and the VIPF5 model dummies were made in 1970. The VIP95 model is a large adult male dummy and the VIPF5 is a small female dummy. These two models are still used by some auto manufactures to test seat belts. Also in 1970, other Sierra models were created. Sierra Susie was an adult 5th percentile female dummy, weighting 104 pounds and was 30.9 inches high when seated. This dummy had the most humanlike appearance to that date, she wore a realistic wig. Sierra Sammy, a six year old, and Sierra Toddler, a three year old, were made. In appearance they looked correct, but neither model was built to the right weight distribution. This threw off the accuracy of test results. Another attempt at child dummies was made in 1971. The VIP3C and the VIP6C, a 50th percentile three year old and a 50th percentile six year old, were developed. The immaturity of a childs skeleton was taken into consideration when making these two models. The spine was made of rubber column constructions. Because the dummies werent very humanlike, their use was limited. But it was the first good attempt in making child test dummies. Many new developments were made in 1972 regarding test dummies. The Hybrid II, a 50th percentile adult male was made to help test seat belts in cars. This model had a humanlike exterior shape, body weight and some realistic joint movements. Some main features in this model included its good repeatability, durability and serviceability. The Supermorophic Dummy, when created, was the most realistic model to that date. Full movement of the limbs, torso, neck and head allowed the dummy to be placed in any position. Dynamic Dan was created and used for testing ejection seats, vibration tests, parachute opening shock tests and other tests involving aircrafts. The OPAT dummy was created and was very helpful in collecting information about seat belts because of its humanlike clavicle and floating scapula and a rib cage that is very similar to a humans. This dummy is still commercially available. In 1973 Repea Pete was developed. It was designed to provide accurate data from frontal impacts and lateral impacts. Because of the lack of repeatability and reproducibility, this model was never commercially available. The Hybrid III, 50th percentile male, weighs 172.3 pounds was made in 1973. It was made to improve the impact response of the test dummy to be more like a human. This dummy has a variety of optional equipment available. Because of this it is one of the most versatile test dummies available. The Hybrid III, 5th percentile female weighs about 108 pounds and is a smaller scaled version of the Hybrid III 50th percentile male, both of these models are still widely used. The Side Impact Dummy (SID) and the European Side Impact Dummy (EUROSID) were made to collect data on human response during a side impact crash, and are still being used.
The test dummies are put through many tests to make sure vehicles are safe. In testing new side air bags, high speed video cameras are place along the sidelines of the testing area. There are also two on board cameras. Red chalk is put on the dummys head and torso to mark the spot where the body hits the steering wheel during the impact. 31 continuous measurements are taken from the dummy during the crash. This information is then analyzed to help produce new and improved automobile designs. In some dummies there are three accelerometers inside the head that measure the deceleration of the head in three different directions, when it hits the steering wheel. Steel, vinyl and graphite layered ribs that deflect like a humans measure the impact on many different body parts, from the pelvis to the knee, then this information is sent to computers to be analyzed. To make sure all of the sensors and physical responses of the dummies are in proper working order, they must undergo many tests. Their chest is hit with a 51.5 pound pendulum, their knees are smashed with federally specified weights and their head is dropped 14 inches onto a . The Safety Test Instrumentation Standards Committee is one of the standards committees under the Vehicle Systems Group. This committee sets and maintains standards for vehicle crash test data. The committee was formed in the 1960s to achieve standards in data. SAE J211 Recommended Practice Instrumentation for Impact Tests was established in October 1970, to help create more testing standards. SAE J211 has been improved over the years as dummy testing has evolved. It now sets standards for electronic data and high speed imaging during tests. It also made the National Highway Transportation Safety Administration, NHTSA. This set a format standard of crash test data files that are exchanged between different test labs.
Finally, despite the price tag of about $100,000 per dummy, crash tests need to be performed. The number of deaths per miles traveled in over 90% lower than it was in 1922. This is partly because of advancement in safety equipment made for data collected from crash dummy testing. Dummies are used so car companies can test their products before sending them out to be sold. General Motors spends about 30% of their dummy testing making sure that the vehicle meets federal standards. The other 70% of the crash tests are to work out the bugs in prototypes of cars and equipment. SID are currently the federal standard for ensuring for making sure that new cars meet the side impact crashworthiness regulations. These side impact tests shows what a crash can do to a persons bones. A new dummies, BioSID gives an overall reading of internal organ injury during a crash. A pregnant model dummy had been made to try and make a seat belt system that is safer for the expecting mother, because about 4000 pregnancies per year end because of automobile accidents. Dummies are used in test to help improve air bags. Of the 105 people killed in the United States by inflating air bags, most of them have been children and small women. So more tests of being done to make air bags safer for these people. New dummies used will have a multi-segmented neck and sensors to better measure the impact of the air bag.
In conclusion, there have been many improvements to crash test dummies since the first model was developed, the dummies are used in many crash tests and the use of these dummies has lead to improvements in automobiles and equipment. With out the information that we have gathered from test dummies, air bags, seat belt and much more would not be a well developed as it is now. This information has helped save many human lives. Hopefully, with more advancements of test dummies in the future, the amount of deaths due to automobiles will continue to decrease.