Cars are considered to be in the top 10 of the most complex mechanisms the humankind ever created. This makes car development and manufacturing processes extremely complex. Car safety and performance requirements are rising with every model. New sensors are being installed to monitor the condition of different modules. New materials and designs are being implemented to increase car power, speed, and safety. All of the things developed need to be tested. At some point, the amount and complexity of tests became so large that a new professional was required.
What Are The Duties Of The Testing Engineer?
A testing engineer is a professional that develops and conducts prototype tests on every level of the manufacturing cycle. He is also responsible for car performance tests on other stages of its lifecycle. Some of the skills required to develop the tests include extensive knowledge in the strength of materials, both static and dynamic. Metrology methods and an experience with measuring tools is absolutely necessary as well as science experimental knowledge.
Key Areas Of Automotive Prototype Testing
It is absolutely vital to test all of the main elements that determine the car performance
- Engine is the most complex and vital element of the car. It is tested on a number of levels starting from its materials. Special conditions are created that are close to the real ones in order to test the yield strength of the chosen materials. After that, when the prototype of the engine is ready, it is loaded with the fuel and the fluids necessary for its operation and with a lot of sensors to test the way it behaves at different conditions. It is then put into action to determine what kind of loads it can withstand. Next stage is installing the engine into an existing car frame and conducting test drives. The final part of engine testing includes checking its performance in a full-scale new car prototype where every part belongs to the developed model.
- Chassis is one of the car elements that withstands the most severe pressures. This is why it is tested for dynamic and static yield strength.Chassis need to endure colossal forces and stay rigid. This is why when a chassis prototype is created, its first tests include bending, stretching and vibrating. After the prototype is found strong enough, it is installed into an actual car model and crash tests are performed.
- Car frame is the element of the car that holds all other assemblies together and protects the driver from harm if a car crash happens. This is why crash tests are the most important ones for a frame. A number of designs is created and the tests are modeled using finite element analysis. Then, the best designs are manufactured into prototypes and supplied with mechanisms that enable it to drive and actual car crash tests are performed using a manikin.
- Steering is the system that allows the driver to turn and control his car. It is directly connected to the chassis and has a hydraulic cylinder in order to decrease the force required to turn the wheels. This is the main testing parameter of the steering system. A dynamometer is installed into the prototype and a special machine is used to turn the wheels while maximum force is measured. Another vital point in a steering system is the air-tightness of the hydraulic cylinder.
- Brakes are performing under severe friction conditions. Brake failures lead to car crashes in almost 95% of the cases and that is why it is so important to check the durability and reliability of those systems. As it is done with most car elements, they are first tested separately on an experimental installation and are then implemented into an actual car prototype. When considering brakes, durability tests are performed, meaning, measuring maximum single time brake performance, and the total time of its operation. Hydraulic systems are also tested for leaking.
- Wheels are the elements that come into direct contact with the road. They must be durable and withstand hard and sharp objects from piercing the tires. This is why here, material testing takes the main role.
Those are the main car assemblies that need to be tested. They are the ones that withstand the highest loads and must, therefore, be manufactured the way that the final part will be manufactured. In some cases, it may take a lot of time to find an optimal design. This is why usually a number of possible designs is chosen and they are all manufactured simultaneously to be tested later.
Rapid Prototyping For Automotive Testing
After testing the elements that withstand high forces during their performance, some other lightly loaded or not loaded elements need tests. For example, car lighting needs to be tested for the way its frame resists impact or gasoline tanks must be tested for leakage and rigidity. In those cases, it is much more efficient to create a plastic rapid prototype using additive manufacturing (layer-by-layer sintering of materials) or resin casting. Those innovative methods enable engineers to greatly decrease the time between the first design testing and the second one.
Automotive prototype testing engineer is the professional who ensures that every car model is safe, reliable and optimized for the consumer. They conduct tests starting from the earliest stages of the design by using modern numerical tools that enable a simulation of the car performance without any need to create the prototype. However, those calculations are not enough because they do not take everything into account. This is why creating prototypes and testing them is the only method that gives reliable info on the element performance. Testing engineers oversee the manufacturing of prototypes because they may need additional holes or cutouts made in the parts in order to install sensors for the testing processes. They also design and manage the manufacturing of testing installations that enable efficient testing of every car element. Without tests, car failures and victims would be much more frequent than are now.