BIG - MEAN SAFE?
One acquaintance, looking after a car for his wife, chose not the cute little Peugeot 206, not the popular compact Ford Focus, but the hefty used Volvo 940: “This tank is one and a half times heavier - while it wrinkles its a two-meter nose, others already have a motor in the cabin!”
What is there to argue? In theory, everything is like that, the laws of physics have not been canceled - two colliding cars move to where the heavier one moved before the impact. He only slowed down, while the light one stopped and then went back.
Accordingly, the overloads will be different, more precisely, inversely proportional to the mass. With the deformation zone, everything is also clear - the larger it is, the lower the overload, here the inverse proportion is also true. In a collision, the long engine compartment saves passengers in both cars: the deformation zones are summed up. In a word, in a big heavy car there is a real chance to stay alive by “fitting” into the maximum allowable overload for the head of 88 g - this corresponds to a power strike of about half a ton! If you are lucky, keep within the boundaries of the "green zone" - 72 g.
However, in the crash tests prescribed by both domestic and European rules, the influence of the mass of the car is not taken into account - the blows are carried out in a hefty concrete cube, weighing at least 70 tons.
At the same time, any car slows down to zero speed - no more, no less. The fact that a deformable obstacle (a block with a honeycomb filler) is installed on the cube does not change things - it imitates another, but still fixed car.
In the life of “opponents” they don’t choose - both the Oka, the Mercedes, and the KamAZ can fly to the Zhiguli’s forehead. How different are the odds of their passengers? And how is practice consistent with theory? To answer these questions, we decided on an unusual, non-stipulated crash test - a head-on collision of two cars …
KamAZ, perhaps, is too much, but a couple of different-sized passenger cars are just right. The role of the baby, without saying a word, was assigned to "Daewoo Matiz" - the modern, most popular A-class foreign car in Russia. As for the opponent, there was no long thought - any model of the “tenth” VAZ family, the newest of the domestic ones. It is also a sales leader in its class.
In order to bring the test conditions closer to the real ones, we decided to beat not new cars, but with mileage - there is such a thing as metal aging, and rust can weaken the structure, then everything will come out. However, you can’t buy a “dark horse” - it is not known whether it was in accidents before and how it affected the car.
Reluctantly, they gave two cars from the editorial park to the slaughter of science - the Daewoo Matiz of 2002, which had just completed the life tests at around 100 thousand km, and the VAZ 2112 of the same age, which had run 56 thousand km. Their biography is known to us for certain - they worked honestly, were not noticed in accidents, minor damage to body panels does not count. Such an ungrateful fate …
TO THE BARRIER!
The determination of the curb weight yielded 831 kg for the Matiz and 1081 kg for the Twelfth. Plus a pair of mannequins in each machine and measuring equipment - a total of 991 and 1253 kg, respectively. The difference was 262 kg - a small car is 21% lighter.
In order for the difference in the behavior of “objects” to be obvious, a very hard, if not cruel, blow is needed.
Therefore, they decided to set the speed of the cars to the same as prescribed by domestic rules for a blow with a partial overlap in a stationary deformable obstacle - 56 km / h (in Europe, according to EuroNCAP requirements, they hit at a speed of 64 km / h). But our “obstacles” are just moving and moving towards with a total speed much higher - 112 km / h! (By the way, don’t you drive along the oncoming traffic?)
Assuming that if anyone has a chance to survive, then the passengers of the heavier VAZ 2112, and also taking into account the high prevalence of such vehicles, it was the “twelfth” that the Hybrid-III mannequins equipped with sensors were seated, the only set of which we had. “Matiz” got the riders not so “smart”.
So, everything is ready: instead of fuel, water is poured into the tanks for safety, the salons and mannequin heads are treated with multi-colored chalk solutions to fix the contact points, the hands of the drivers with tape are fixed to the steering wheels.
Cars are routed to different ends of the acceleration zone and attached to steel shoes, which the winch ring cable pulls along the central rail. Readiness countdown teams thundered from the reproducers, and finally … “Start!”
Buzzed the cable, accelerating faster. Two cars fly into the marked area. A soft blow, fireworks of fragments, mannequin heads flickered in the openings of open windows - and everything instantly ended. The eye captures only the slowly rolling away Matiz.
Everything, finite. We will evaluate the results.
WHAT IT ENDS
DEU-MATIZ. Lighter, it rolled back 5.4 m. Moreover, it rolled away - the wheels rotated freely. The upper part of the engine compartment is completely wrinkled, the radiator lining was almost under the edge of the windshield.
A sturdy subframe with suspension elements, seemingly whole, shifted back a little. The front wheels went back 50 mm to the left and 65 mm to the right. The motor shifted back, but did not go down. The battery crashed, “insuring” against short circuit and fire. The tank remained intact without having been hit by any other elements. The left side of the body is deformed a little more. The racks, transferring part of the impact energy to the roof, lifted it, forming cracks above the doors - 80 mm to the left and 20 mm to the right.
The left pillar slightly folded and lost its inner lining. There are no visible signs of deformation on the doors, all four have opened, the driver’s one with effort, but without the help of a tool. Three doors can still be closed. All the windows are intact, except for the windshield - it cracked strongly in the lower part, but remained in the opening. Exterior mirrors even retained the adjustments. In the cabin, the front seat frames are deformed - the pillows are noticeably tilted down, which provoked diving of riders under the seat belts. The steering wheel is bent, the column is shifted 40 mm backward and 45 mm downward, there are traces of a blow to the driver’s head. Broken left steering column switch.
On the front panel there are marks of contact with the knees, the glove box cover is broken. On the passenger’s lap - traces of a header. Contact with the uprights, roof and front panel did not occur. Seat belts are intact, their locking mechanisms are not damaged. Deformation of the floor is negligible, although the front part is noticeably raised.
Living space in the cabin is fully preserved. So a small machine is not such a fragile soap dish.
VAZ 2112. After the impact, the car remained in place. The lower part of the front end is more deformed, while the hood is only half wrinkled. From the side members, as if from skewers, the entire “hitch” moved back, and they themselves pierced the front of the Matiz. Damage to the front suspension is more noticeable. The sides of the engine compartment folded inward, the cups of the front struts went to the center and back. The motor is moved back until the intake manifold touches the shield.
The battery has remained operational (after a stroke, light was on in the passenger compartment), which increases the risk of fire. The gas tank is not damaged, but there are traces of a blow by the exhaust system. The deformation of the front pillars and the roof is noticeably less than that of the Matiz. Doors - without visible damage, although the driver’s jammed, I had to use a crowbar.
Other doors were opened without tools, the front right - with effort. But now you can close only the rear doors. The windshield cracked at the bottom edge, but remained in the opening.
Inside, the deformation of the front seat cushions is noticeable, the mechanisms of their longitudinal movement are damaged. The chairs themselves leaned forward a little because of the deflection of the floor at the front points of their attachment.
The front part of the floor “stood on end”, however, the legroom, as well as the living space as a whole, is preserved. The steering wheel rim and hub are deformed, the column has shifted (mainly backward) by 80 mm. The column cover is destroyed, the glove box lid is broken by the passenger’s knees, the climate control unit flew out. Seat belts are intact, their braking mechanisms are functional.
And PEOPLE HOW?
The main conclusion regarding the passengers of the VAZ 2112 is that with a high degree of certainty it can be argued that the mannequins remained “alive”. Although the driver most likely suffered a concussion, injuries to the neck and right lower leg, and the passenger received injuries to the neck and chest: injuries in these areas reach 80–90% of the maximum allowable.
With the crew of "Matiz" is not so simple. Unfortunately, here mannequins are not able to tell about the transferred, because the accuracy of our conclusions is lower than for VAZ 2112. The mannequins are not pinched, the doors opened freely, the risk of fire of the car is low - this is already good.
But the difference in the masses of the machines (Matiz has 21% less) results in its equally more intensive deceleration upon impact. This means that injuries will increase in about the same way, although a smaller oncoming course of the steering column will reduce the most critical load - on the neck and head of the driver. In general, the strike of such a force for the Matiz will most likely be ultimate - when the crew still has a chance to survive. And the outcome of a real collision will depend on random factors - the direction and angle of impact, the position of riders in the seats, their height, weight, physical strength, finally.
Unfortunately, we inexcusably disregard our health and safety - not all are fastened with a belt, and there is nothing to “overpay” for additional safety equipment when you just scraped into an inexpensive car. But after all, if anyone needs additional protection, then first of all the "kids"! In Europe, the same Matiz, for example, must be equipped with pyrotechnic belt tensioners and frontal airbags - with such a set, it would surely save the life of the crew.