I crashed my Mitsubishi Evolution X Crash test on scale
I break down a scale model, an exact copy of the Mitsubishi Lancer Evolution X. Which I made with my own hands from scratch using clay for this. This machine is made of plasticine. I broke my work in order to show you how a plasticine car breaks down on a small scale like a toy, but much more realistic. It turned out to be the most epic and realistic crash test.
Separate frames placed in the basement
These types of frames are located under the cabin / cockpit and have hardly existed in the automobile since the end of the 90s. The elements are fixed to each other (cab to frame) by bolts and silent blocks .
This type of frame rests primarily on a heavy-gauge center beam that runs the length of the vehicle. The bodywork is fixed above the latter, so there is a separation between the cell/passenger compartment and the chassis. Its resistance to side impacts is logically average ...
We often speak of the old Alpine to designate an example of a car that benefits from this architecture.
This type of chassis is still used on trucks and some 4x4s such as the aging but no less popular Mercedes G-Class. It looks a bit like the beam frame except that instead of resting on a main axis it is made up of several metal sections that form a kind of H or even a ladder, hence its name.
Among the advantages, we can mention its good capacity to withstand heavy loads (trucks or bridge crossings in off-road use). As a result, it is also quite easy to repair in the event of deformation (passage to marble). Unfortunately, the fact that it is not integral with the body makes it much less effective in the event of an impact, because there is no coordination between the passenger compartment and the chassis. We can therefore end up with two types of phenomena in the event of an impact: if it separates at this moment, the chassis can slide backwards without absorbing the impact while the top (the cabin which houses the occupants) crushes under the most stress. If the assembly remains united, the frame which is very rigid will not deform: the deceleration will then be such that the passengers risk not surviving (the organs have a limit with regard to the number of Gs collected). This is the famous problem of too resistant cars at the time.
On the other hand, if the car hits a deformable obstacle (eg: car coming in the face), it is the obstacle that will absorb the impact the most. So in this case it is better to be a passenger in the rustic 4X4 than in the modern car which will bend heavily! Despite everything, it remains difficult to make generalizations because the variables can vary greatly from one car to another.
Very similar to the ladder chassis, this time it has a floor. The shell that will be grafted on top will therefore not have to have "soil". We could therefore almost drive the car here without its cabin, unlike other types of chassis of this ilk.
The tubular chassis is intended for competition. It combines both very light weight (there is a lot of space) and high rigidity. Round-shaped tubes allow just that, because the circular shape is the most resistant thanks to a very homogeneous distribution of forces (square tubes are much less resistant, that's why the frames of your bikes, among others, are generally round ).
This type of chassis can be easily assembled by a single person in a simple garage. Many amateurs also have fun making them on their own, something that remains complicated for other types of chassis...
Hull frame / self-supporting
This is the chassis that equips modern production cars. It is in fact a sort of ladder frame that is merged with the bodywork. By stamping them together, these elements form only one: the shell frame, also known as the self-supporting shell.
The main advantage is to be able to manufacture a kind of homogeneous cage (the rigidity is therefore distributed over the whole of the body and not mainly on the chassis located in the base) whose deformation we will be able to control in the event of an impact. Some areas are very strong to have a rigid chassis and others are deliberately fragile to direct the deformation (slides even plan to pass the engine under the car so that it does not end up in your legs. This is all the easier thanks to CAD (computer-aided design) which allows them to be simulated on a screen, and therefore to refine the structure without having to carry out crash tests (which will still be carried out later for verification).
Note in passing that this type of shell is designed to withstand a shock at 3 km / h without subir of damage (it is the shield which has the task of absorbing the shock) and 15 km/h without the structure being affected (a small easily recoverable deformable zone is located at the front). To know the EuroNCAP crash test standards go here.
Finally, the fact that the body and the chassis are integral makes it possible to gain in rigidity, provided of course that the design is good and that the caliber of the stamped sheets is sufficient.
To gain in rigidity (but also in safety), production cars adapted for competition also benefit from a tubular structure on the inside: this is called the cage arch. It is fixed to the hull chassis at strategic points, thus implying the need to remove many elements in the passenger compartment (this, however, allows for beneficial lightening).
Unlike a ladder chassis, a shell chassis is much more difficult to recover in the event of deformation. It is therefore almost always irreparable and the car must then be condemned to end up in the scrapyard...
Convertibles are derivatives of cars designed with a self-supporting body, it is therefore necessary to add reinforcements to the latter so that the chassis is not too flexible (possible torsion when cornering and braking). This increases the weight of the car...
Finally, the type of self-supporting chassis brings better comfort (less vibrations) but also better road handling even if it will still depend on which car we are talking about (quality of design / more or less demanding constraints of the specifications) .
Other types?
There are other ways to design a chassis, the mechanics and the design of things is only limited by human imagination. For example, if we look at how a mid-engined supercar is made, we realize that there are three zones: the front is similar to tubular (but with large rectangular sections), the center (cell of survival) looks like a shell chassis and the rear takes up the principle of the front with large square aluminum tubes that look like tubular.
Here is the chassis of an Aventador. The rear structure therefore also serves as an engine cradle knowing that the latter (the engine) will contribute to the rigidity of the chassis. We can even say that it is a key part of the chassis.
Finally, if we take the example of an MX5, we end up with two processes that merge: the self-supporting body (shell chassis) and a beam chassis.
Aluminum is used more and more in the construction of chassis because it makes it possible to gain in lightness (it is mainly found in the top of the range and on prestige cars). However, aluminum is not perfect... It is indeed less resistant (under stress, it tends to break rather than twist) than other metals and it is therefore necessary to calibrate larger parts. However, the final weight will always be lower than steel because even by calibrating it larger, you ultimately benefit from a lighter part. Roughly speaking, to obtain an aluminum part as resistant as another in steel, we will have a slightly larger element (to make up for the lack of rigidity) but less heavy despite everything.
Note that aluminum is more difficult to repair because the welds to be made are more technical (high thermal conductivity, high expansion when heated, melting point at 650 degrees instead of more than 1300 for steel, etc.). On the other hand, it does not undergo corrosion, which is an advantage for aging
Carbon fiber chassis
Carbon makes it possible to lighten the chassis even further while maintaining exceptional rigidity. However, it also has drawbacks, it is expensive and energy-consuming to manufacture. In addition, the manufacture of parts is very special because we are dealing here with a kind of fiber fabric that hardens in the oven. Basically, to make a part, we will superimpose several molded and baked layers that we will glue together. Also note that this material is irreparable because it cannot be worked. Moreover, it tends to leave in thousand pieces in the event of shock...
However, there are now composite alloys (mixing other materials) which reduce its brittleness.
Modular platforms
Nowadays, manufacturers are designing platforms/chassis that can be used for both a compact or an SUV, the aim being to reduce development costs. It is in fact to develop a floor that can be lengthened or shortened by adding or removing sections (modifies length and wheelbase). The hull is then adapted to then be fused
I crashed my Mitsubishi Evolution X Crash test on scale
I break down a scale model, an exact copy of the Mitsubishi Lancer Evolution X. Which I made with my own hands from scratch using clay for this. This machine is made of plasticine. I broke my work in order to show you how a plasticine car breaks down on a small scale like a toy, but much more realistic. It turned out to be the most epic and realistic crash test.
Separate frames placed in the basement
These types of frames are located under the cabin / cockpit and have hardly existed in the automobile since the end of the 90s. The elements are fixed to each other (cab to frame) by bolts and silent blocks .
This type of frame rests primarily on a heavy-gauge center beam that runs the length of the vehicle. The bodywork is fixed above the latter, so there is a separation between the cell/passenger compartment and the chassis. Its resistance to side impacts is logically average ...
We often speak of the old Alpine to designate an example of a car that benefits from this architecture.
This type of chassis is still used on trucks and some 4x4s such as the aging but no less popular Mercedes G-Class. It looks a bit like the beam frame except that instead of resting on a main axis it is made up of several metal sections that form a kind of H or even a ladder, hence its name.
Among the advantages, we can mention its good capacity to withstand heavy loads (trucks or bridge crossings in off-road use). As a result, it is also quite easy to repair in the event of deformation (passage to marble). Unfortunately, the fact that it is not integral with the body makes it much less effective in the event of an impact, because there is no coordination between the passenger compartment and the chassis. We can therefore end up with two types of phenomena in the event of an impact: if it separates at this moment, the chassis can slide backwards without absorbing the impact while the top (the cabin which houses the occupants) crushes under the most stress. If the assembly remains united, the frame which is very rigid will not deform: the deceleration will then be such that the passengers risk not surviving (the organs have a limit with regard to the number of Gs collected). This is the famous problem of too resistant cars at the time.
On the other hand, if the car hits a deformable obstacle (eg: car coming in the face), it is the obstacle that will absorb the impact the most. So in this case it is better to be a passenger in the rustic 4X4 than in the modern car which will bend heavily! Despite everything, it remains difficult to make generalizations because the variables can vary greatly from one car to another.
Very similar to the ladder chassis, this time it has a floor. The shell that will be grafted on top will therefore not have to have "soil". We could therefore almost drive the car here without its cabin, unlike other types of chassis of this ilk.
The tubular chassis is intended for competition. It combines both very light weight (there is a lot of space) and high rigidity. Round-shaped tubes allow just that, because the circular shape is the most resistant thanks to a very homogeneous distribution of forces (square tubes are much less resistant, that's why the frames of your bikes, among others, are generally round ).
This type of chassis can be easily assembled by a single person in a simple garage. Many amateurs also have fun making them on their own, something that remains complicated for other types of chassis...
Hull frame / self-supporting
This is the chassis that equips modern production cars. It is in fact a sort of ladder frame that is merged with the bodywork. By stamping them together, these elements form only one: the shell frame, also known as the self-supporting shell.
The main advantage is to be able to manufacture a kind of homogeneous cage (the rigidity is therefore distributed over the whole of the body and not mainly on the chassis located in the base) whose deformation we will be able to control in the event of an impact. Some areas are very strong to have a rigid chassis and others are deliberately fragile to direct the deformation (slides even plan to pass the engine under the car so that it does not end up in your legs. This is all the easier thanks to CAD (computer-aided design) which allows them to be simulated on a screen, and therefore to refine the structure without having to carry out crash tests (which will still be carried out later for verification).
Note in passing that this type of shell is designed to withstand a shock at 3 km / h without subir of damage (it is the shield which has the task of absorbing the shock) and 15 km/h without the structure being affected (a small easily recoverable deformable zone is located at the front). To know the EuroNCAP crash test standards go here.
Finally, the fact that the body and the chassis are integral makes it possible to gain in rigidity, provided of course that the design is good and that the caliber of the stamped sheets is sufficient.
To gain in rigidity (but also in safety), production cars adapted for competition also benefit from a tubular structure on the inside: this is called the cage arch. It is fixed to the hull chassis at strategic points, thus implying the need to remove many elements in the passenger compartment (this, however, allows for beneficial lightening).
Unlike a ladder chassis, a shell chassis is much more difficult to recover in the event of deformation. It is therefore almost always irreparable and the car must then be condemned to end up in the scrapyard...
Convertibles are derivatives of cars designed with a self-supporting body, it is therefore necessary to add reinforcements to the latter so that the chassis is not too flexible (possible torsion when cornering and braking). This increases the weight of the car...
Finally, the type of self-supporting chassis brings better comfort (less vibrations) but also better road handling even if it will still depend on which car we are talking about (quality of design / more or less demanding constraints of the specifications) .
Other types?
There are other ways to design a chassis, the mechanics and the design of things is only limited by human imagination. For example, if we look at how a mid-engined supercar is made, we realize that there are three zones: the front is similar to tubular (but with large rectangular sections), the center (cell of survival) looks like a shell chassis and the rear takes up the principle of the front with large square aluminum tubes that look like tubular.
Here is the chassis of an Aventador. The rear structure therefore also serves as an engine cradle knowing that the latter (the engine) will contribute to the rigidity of the chassis. We can even say that it is a key part of the chassis.
Finally, if we take the example of an MX5, we end up with two processes that merge: the self-supporting body (shell chassis) and a beam chassis.
Aluminum is used more and more in the construction of chassis because it makes it possible to gain in lightness (it is mainly found in the top of the range and on prestige cars). However, aluminum is not perfect... It is indeed less resistant (under stress, it tends to break rather than twist) than other metals and it is therefore necessary to calibrate larger parts. However, the final weight will always be lower than steel because even by calibrating it larger, you ultimately benefit from a lighter part. Roughly speaking, to obtain an aluminum part as resistant as another in steel, we will have a slightly larger element (to make up for the lack of rigidity) but less heavy despite everything.
Note that aluminum is more difficult to repair because the welds to be made are more technical (high thermal conductivity, high expansion when heated, melting point at 650 degrees instead of more than 1300 for steel, etc.). On the other hand, it does not undergo corrosion, which is an advantage for aging
Carbon fiber chassis
Carbon makes it possible to lighten the chassis even further while maintaining exceptional rigidity. However, it also has drawbacks, it is expensive and energy-consuming to manufacture. In addition, the manufacture of parts is very special because we are dealing here with a kind of fiber fabric that hardens in the oven. Basically, to make a part, we will superimpose several molded and baked layers that we will glue together. Also note that this material is irreparable because it cannot be worked. Moreover, it tends to leave in thousand pieces in the event of shock...
However, there are now composite alloys (mixing other materials) which reduce its brittleness.
Modular platforms
Nowadays, manufacturers are designing platforms/chassis that can be used for both a compact or an SUV, the aim being to reduce development costs. It is in fact to develop a floor that can be lengthened or shortened by adding or removing sections (modifies length and wheelbase). The hull is then adapted to then be fused
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