The dummies used for crash tests play a key role in car safety: increasingly high-tech and with different body sizes, they are covered with sensors that enable highly accurate measurements at dozens of points.
Although computer simulation tools are becoming increasingly important in the development of new cars, when it comes to mobility and safety, crash tests continue to play a key role. Škoda has its own extensive crash test laboratory, where up to 300 crash tests a year are carried out: the safety of cars is tested in practice, under strictly defined conditions, on an almost daily basis.
The importance of dummies
Specific crash test dummies are the key players in safety tests involving cars and obstacles, lights, cameras and sensors of various kinds. In recent years, crash tests have become more and more stringent and demanding, and this is also reflected in the fact that Škoda is using an increasing number of dummies.
Until a few years ago, only a few types were required; today, however, at least twelve are used: eight reproduce the bodies of adults and four are child dummies, representing children aged one and a half, three, six and ten. Why so many? This variety is necessary in order to be able to thoroughly test safety in different situations and considering different types of passengers.
Safety in every situation
"We use different types of dummies to represent different genders and sizes, including children. The sizes and design of the dummies are based on the requirements of individual homologation regulations, consumer tests, and internal requirements that take into account population distribution", explains Jan Domkář, Škoda's Car Safety Development Coordinator.
Each type of dummy reacts uniquely in a particular test and interacts differently with restraint systems and vehicle design. The goal is precisely to test as many options as possible to ensure that both adult passengers and children are well protected wherever they sit inside the vehicle.
Males and females
A slightly different dummy is needed for each type of test. "For frontal impacts we use the Hybrid III or Thor, while for side impacts we use the EuroSID II and WorldSID", Domkář adds. The dummies, moreover, are defined by a percentage marking; a concrete example: '50% male,' representing an average male in terms of height and weight. For simulations involving women, on the other hand, the '5% female' dummy is mostly used, which is so named to indicate that only 5% of the women are physically smaller than the dummy.
In any case, only standardized dummies are used in crash tests, in line with the requirements defined by the most rigorous tests, such as those carried out according to the EuroNCAP methodology. The same dummies are used in both official and internal tests, which Škoda performs to verify the safety level of cars during the development stage, before putting them through official tests.
The dummies are made of a wide range of materials: the basic framework is made of metal, which is strong and durable, while the body is made of a mix of materials that simulate as closely as possible the behavior and reactions of the human body in specific situations. Special metals are used for the ribs, spine, or joints, while the skin and pelvis are made of specific plastics. The loads to which these parts are subjected during the crash test are then measured, allowing the deduction of the location and extent of injuries that would occur in an accident.
Each individual part is replaceable, so each dummy is reusable and has a theoretically unlimited lifetime. Many elements of the dummies are patented, and there are only a few manufacturers that produce them; as a result, their price is significantly high, so that they are often the most expensive piece of equipment used in a crash test. "The Thor frontal dummy costs 650,000 euros, and the WorldSID side impact dummy 350,000 euros; to these figures must be added the costs of service and calibration" resumes Domkář, who then points out that calibration must be performed after a certain number of tests, or when biomechanical limits are exceeded.
All kinds of sensors
Each dummy - whose technology is constantly evolving - is fitted with dozens of sensors that measure acceleration, forces and deformation. For example, while the Hybrid III dummy used at the beginning of the millennium for simulating frontal impacts allowed measurements at 56 points on the body, the current Thor allows measurements at 116. Similarly, the EuroSID2 dummy for side impact had 57 measurement points, compared to 94 for today's WorldSID. The latter is also much more closely resembling the human body, with a rating of 7.6/10 compared to 4.6/10 for the older dummy.
The more technology advances, the more new types of dummies appear in the tests. "Currently, further work is being carried out on Thor and WorldSID dummies that will represent 5% of women, but another trend in this field is to represent the more advanced age of passengers", Domkář concludes.
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