The Evolution of the Crash Test Dummy
While all the automotive companies advertised safety for decades, most of them performed miserably in both crash tests and real life crashes. The simple logical truth is they didn’t care about the expensive cost of safety development and just falsely advertised it. And if you look on the other hand at crash tests from the 60s, 70s and 80s, well you won’t see much difference because there really isn’t. Because, as good profitable companies do, they were just using the psychological image that they were creating safer cars, but just to make big bucks. My point for this argument is that the quality and success of a crash test dummy is measured in the safety features automakers implement in their vehicles in order to better protect humans and not in the number of airbags or the number of electronic vehicles assists that are advertised nowadays to boost sales.
It is true that the rate of technological advancement didn’t allow for better results... or did it ? Keep on reading to see just what I’m talking about.
The beginnings of the crash test dummies
Well let’s start with explaining first what a crash test dummy is and what is its role. A crash test dummy represents an anthropomorphic (or humanoid if you like) test devices (ATD) which tries to accurately reproduce a person’s body movement in simulated vehicle impacts. And as I said earlier the quality and success of a dummy is measured in the safety features automakers implement in their vehicles in order to better protect passengers. Now the efficiency of a dummy is a different thing and this is measured in its ability to gather a wide and accurate array of data about a human’s dynamic behavior in the case of a car crash.
Society’s interest in promoting improved safety solutions for motor vehicles came soon after the world’s first few automotive related accidents. For those of you interested in these facts the first recorded victim of a steam-powered automobile accident was Mary Ward. It happened on August 31, 1869, 17 years before Karl Benz would invent the first gasoline-powered automobile. In North America, the first recorded automotive-related death happened on September 13, 1899, when Henry Bliss was hit while stepping off a New York City trolley.
In the beginning the first approach for improving safety was to understand how a human body would react to frontal crashes. This of course lead to the development of the safety belt and then focus was channeled primarily on the driver’s seat, although dashboard structures and the car itself were built very rigid and the whole impact force was transferred directly to the occupants.
The first serious tests were conducted by Detroit's Wayne State University, and the first crash test dummies were, well... human cadavers. Of course there were ethical and moral issues regarding the use of deceased people as test dummies, but researchers argued the bodies would be relevant to the study and their use would help save lives. This gave the use of cadavers an honorable cause and dismiss claims of desecration. But cadavers were useful only once and only if the people died of natural causes, as any previous injuries would hinder the correct determination of those provoked by the crash.
With animal testing, dummy research progress dealt with strong opposition from animal rights groups, especially the American Society for the Prevention of Cruelty to Animals (ASPCA). The most helpful animals used in that short period of time were pigs, which testers say had an internal structure similar to that of humans. Animal testing played an important role when engineers tried to understand and come up with a solution for the fatalities caused by steering wheel column impalement, as both cadavers or live subjects couldn’t have been used.
Entering the world of mannequins and virtual passengers
The solution for the steering wheel impalement problem came with the collapsible steering wheel column, which was invented by Mercedes-Benz engineer Bela Bareny, and was first implemented in the US by Chevrolet in 1965. But again, the use of animals for testing had reached both a functional and ethical limit, so scientists and researchers had to find a more evolved way of simulation human behavior in automotive crashes.
The first test dummy in the way everybody knows it today was “Sierra Sam”, created by Samuel W. Alderson at his Alderson Research Labs (ARL) and Sierra Engineering Co. in 1949. The dummy was much taller and heavier than an average adult male and it was used to test aircraft ejection seats, aviation helmets and pilot restraint harnesses. After this, Alderson created the VIP-50, which was a test dummy specifically built for General Motors and Ford, while Sierra introduced a rival model called the “Sierra Stan”.
Later on, GM tried to encompass the best features of the VIP-50 and Sierra Stan models into a single test dummy and came up with the Hybrid I model. This model was also known as the “50 percentile male” dummy, because it resembled an average man in height, weight and proportion.
The result was introduced in 1976 and was dubbed the Hybrid III. This 5th percentile male dummy is 5’9” tall and weights 170 lb. The Hybrid III dummy is used by the Insurance Institute for Highway Safety (IIHS) and is the most wide spread test dummy in use today. In order to enhance the results spectrum, Hybrid III was joined by a whole family, including a 5th percentile female dummy and three Hybrid III child dummies that represent a ten year old, six year old and a three year old. A larger male dummy, dubbed the 95th percentile Hybrid III was also introduced to measure the dynamics of a larger size person and compare how the crash results affect persons of different build and sizes.
Modern test dummies must be able to record several variables like velocity of impact, crushing force, bending, folding and deceleration rates during a collision for use in crash tests.
The Hybrid III model does have its limitations, but thanks to its versatile design, parts are interchangeable and can be adapted to other needs. This test dummy was designed for frontal impact measurements and is not as helpful in side impacts, rollovers and rear impacts. But where they are limitations there also new solutions, previously unseen.
Further developments starting from the Hybrid III test dummy family include:
- SID (Side Impact Dummy) specially designed to measure rib, spine and internal organ shocks and compression of the chest cavity in side collisions.
- BioRID is a development of the crash test dummy which helps to more accurately assess whiplash trauma from a rear impact. This proved very helpful in designing efficient head and neck restraints. The BioRID test dummy’s ability to assume a more natural seating position comes from its 24 vertebra simulators.
- CRABI represents a child test dummy used to better measure the effectiveness of child restraint systems. It comes in three age versions: one 18-month year old, a 12-month and a 6-month dummy.
- THOR is an advanced 50th percentile male dummy and official successor of the Hybrid III model. It features an improved spine and pelvis structure in order to better resemble a human and comes with an innovative array of face sensors meant to determine how objects impact a human face during a car crash.
- THUMS (Total HUman Model for Safety) is an advanced crash test dummy from Toyota Motor Corporation (TMC). Recently arrived in its 4.0 version, this average male dummy builds on the previous generation (which added a bone-like structure and brain) by adding detailed models of internal organs. This new feature will prove to be extremely important as past automotive crashes from real life demonstrated the tightness of a seat belt even coupled with an airbag do not prevent the internal organs of a human being from retaining their inertia, leading to hemorrhages. The THUMS 4 from Toyota allows researchers and engineers to determine how and to what extent areas of the torso and internal organs are damaged during a collision.
Toyota Technical Development Corporation who is in charge of the THUMS project plans to add a larger male and a small female to its crash test dummy range. TMC also has plans to sell the THUMS 4 dummy from autumn 2010.
Outlook for future crash test dummies
THUMS 4 was developed with the help of research institutes and universities using a high-precision computed tomography (CT) scanner to make detailed measurements of the internal structure of the human body. And this is how the future looks like, a combined work of independent research institutes and universities using advanced computer simulations to reproduce crashes in order to better understand how to improve passenger safety.
Another important area in this respect that has intrigued researchers is the simulation of a pregnant woman behind the steering wheel in a collision. The first prototype model of a pregnant woman crash test dummy was made by Loughborough University UK. They fitted a container with fluid above the pelvis to simulate the womb. Their research was aimed at finding a proper seat belt design for pregnant women, as studies showed most pregnant women gave up on using the seat belt due to discomfort.
Even though the importance of computer generated crash simulations will most likely take over in the next years, we believe the future resides in the combination of virtual collisions and advanced test dummies. While the computer software will advance to the state of reproducing geometrically correct simulations and accurate impact readings, the crash test
The computer will help in the sense of reproducing a myriad of crash situations, from different angles and with different objects at various speeds, but steel is just steel and welding points are just welding points, so the relativity of all things commands the imperative use of full-scale anthropomorphic test devices and real-world testing rigs.
The only thing is, companies should start implementing technological advancements (like crumple zones, intelligent airbags, non-hazardous dashboards and advanced seating designs) sooner, because it appears they've focused to much on developing the crash test dummies while forgeting why they developed them for. 60 years after the first crash test dummy was invented and over 90 years since people understood the need for improving vehicle safety, horribly gone wrong crash tests still hit hundreds of thousands of clicks on YouTube.