What is a Car Crash Test and How It Works?

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You must be familiar with the concept of crash tests of vehicles if you are interested in the automotive sector. One of the major concerns that buyers have when purchasing a new vehicle is related to its safety. 

Manufacturers, therefore, conduct such tests to ensure their safety before the buyers, attracting their faith towards the products. 

Read on to find out more about a car crash test

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There are various safety issues while driving, and crashes are the most common ones. While one cannot plan and prevent accidents in advance, it is always advisable to stay aware and careful to avoid the possibility of crashes. 

A crash test aims to predict such crashes in advance and preventing these with proper strategies. Manufacturers of a particular vehicle use a series of destructive procedures in this type of test. 

This helps to predict the post-accident dynamics, which can help develop ratings, dummies and future improvements for a vehicle. The results help the owners of vehicles become more careful while driving.

Before learning how crash testing works, it is important to know the kind of equipment manufacturers use for this process. Apart from the car to be used, here are the equipment needed for conducting such a test:

Crash Test Dummies

These are the human-like figures that go inside a vehicle during a test. Such figures are usually made of metals and composites with some sensors placed inside them. The purpose of placing dummies is to check the level of damage the crash can cause to the people who might be riding inside it.

Impact Trolleys

Trolleys are used to replicate accident media. These might include oncoming vehicles and other obstructions. Made of aluminium and steel, a trolley is propelled at the test subjects from various angles during a crash test to check its impact.

Imaging & Data Analysis Architecture

Crash tests involve advanced and sophisticated technology and electronics, such as sensors, cameras, and analysis software. This helps to analyse the impact of an accident, which is both visual and in-depth.

As discussed earlier, a car crash test is usually done with the help of dummies placed inside vehicles. They come in various sizes, representing various percentile and gender, simulating human beings during an accident. Three types of instrumentation are seen in a crash test dummy:

Accelerometers

These are devices that measure acceleration in a particular direction. The result from this device is essential to evaluate the probability of injury. In simple terms, acceleration refers to the rate of speed changes. Multiple accelerometers are placed inside a dummy, including its head, chest, legs, pelvis, etc. 

It highlights the impact that a human will face if he/she hits a body part. Graphs represent the impact of a crash. For instance, a head bang on a hard surface will have much more impact than a bang on a pillow. The graph helps show the changes in the pain level one might feel when hitting different objects.

Load sensors

Apart from the accelerometers, manufacturers also place some load sensors inside a dummy. It helps measure the amount of force applied to different body parts. Again, graphs are used to depict changes in the level of impact that affect the dummies when they are exposed to a crash, and their body parts hit different objects.

Motion sensors

These are other types of sensors commonly placed in the dummy's chest. The graphs generated in this type of sensor depict the deflection in the dummy’s chest during a crash. The ups and downs in the graphs help to understand whether a crash will be painful to human beings.

A car crash test can be a complicated one. Various steps and stages contribute to this process. Here is a step-by-step guide to the procedure of a crash test:

Crash Test Paint

This process starts with applying paint to a crash test dummy. This is an important step, as different colours are usually allotted to different body parts. The face, areas of the skull and knees must have a specific colour. These are usually smeared on the car after this test. In case of a large acceleration from the accelerometers, the colour will help to identify the body parts and the part of the vehicle it hit.

Vehicle Setup

The next step is to prepare the vehicle for a crash. For this, manufacturers place dummies properly within this vehicle and set up all the cameras, sensors and other software. They add ballast to the car to ensure proper distribution of the weight of a fully-loaded vehicle. High-speed cameras and speed sensors are placed to record this crash.

Crash & Aftermath

The next step is a crash, which is done with the help of trolleys. However, it is not the end of this procedure. Manufacturers have the role of checking the results and rating this crash. For instance, if the car’s front is completely crushed, it is a good sign. It indicates that the car is capable of absorbing its kinetic energy to reduce the impact of an accident.

There is hardly any limit to the types of accidents that can occur in a vehicle. Global NCAP, or New Car Assessment Program, is responsible for conducting crash tests in India. Here is a list of the common types of crash tests that NCAP conducts frequently:

Frontal Crash Tests

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The most common type of accident is the front collision. Therefore, manufacturers spend long hours and work on advanced engineering to create strong and safe front ends of vehicles. 

In this type of test, a car collides with both static and dynamic barriers. While head-on collisions are distributed quickly across a vehicle, offset collisions cause a much lesser distribution of force.

Roof Strength Tests

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While this type of accident might seem rare, they are the ones with a major impact. In a rollover accident, a car is likely to turn over onto its roof. If the roof collapses, occupants get crushed under its weight. 

In this type of test, manufacturers place the roof of a car under duress. They check the peak resistance it offers before crumbling. The strength-to-weight ratio or computation checks how long a vehicle can stand after an accident.

Side Crash Tests

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The sides of a vehicle are more likely to expose its occupants to danger than the front. In this type of test, an impact trolley with a stationary vehicle collides with the main car at right angles. This causes a car to deform. 

Manufacturers check the structure of their pillars and door frames in this test, which are essential for absorbing the impact of such an accident. Airbags are common in vehicles these days to prevent their impact.

In a perfect world, there shouldn't be any crashes at all. However, in this scenario, a perfect crash represents an accident which will have the maximum survival chances of the occupants. Kinetic energy within a vehicle has a major part to play here. When a car moves, its energy is high and reduces to zero when it crashes. The trick here is to ensure that this energy reduces slowly and evenly to ensure minimum damage from a crash. 

Usually, the seatbelt pre-tensioners and force limiters in your vehicle tighten up the seatbelts as soon as it hits a barrier. This happens before the airbags deploy. Seatbelts absorb some energy as you move towards the airbags, and the force limiters ensure that your seatbelts never get too high. 

Then, the airbags deploy and absorb some part of the forward motion, protecting the occupants from hitting hard surfaces. This is an example of a perfect hypothetical crash, which will have little to no impact.

After conducting a car crash test, manufacturers or higher authorities provide crash test ratings. This rating, usually on a scale of five stars, determines how safe a car is after its crash test and whether it will be ideal for buyers to prevent accidental damage. Currently, NCAP offers this rating considering Adult Occupant Protection and Child Occupant Protection scores. 

Various factors play important parts in determining a vehicle's score following a crash test. Measurement of loadings is one of these. Another one can be decelerations that dummies sustain during a crash. Vehicles with advanced safety features receive additional points. A driver’s side airbag is mandatory even for a one-star rating. 

At present, an emphasis is put on making the safety features of vehicles more advanced and smart. A recent advancement in this field has been that of smart airbags. Depending on an occupant’s seating position and weight, he/she can deploy these airbags at different speeds and pressures.

At times, deploying airbags can cause injuries to the occupants. This new technology will eliminate this risk, enhancing the quality of airbags. New technologies will also allow seatbelts to sense the position and weight of occupants and adjust their force and tension accordingly. Thus, car manufacturers are likely to create safer vehicles in future with sophisticated safety features. 

Hopefully, that gives you a detailed account of a car crash test and its importance in examining a car's safety features. As per this article, such tests are necessary for car manufacturers to check whether a vehicle will be able to survive in crashes. They might plan different safety features if the crash ratings are low.