The vibrations that vehicles and any other machinery generate during use are another environmental agent to be considered when assessing the durability and structural integrity of vehicle components
In terms of product design, it is important to detect the points most sensitive to vibrations to decide where to reinforce the structure and minimize the risk of damage and early breakage of devices during use.
Vibration testing: application and testing types
In vibration testing, we subject parts and devices to controlled, reproducible vibration conditions using an electrodynamic vibrator. It consists of a vibrating platform, a power amplifier, a controller and accelerometers. The part is firmly attached to the platform armature using a specifically designed tool. The controller sends vibration orders (such as a frequency profile established for a testing standard) to the platform via the amplifier. The accelerometers are placed on different points of the device to check the part’s response to external agents in the form of displacement, speed and acceleration.
When testing is finished, the part or device is checked to ensure that it has not suffered structural damage and has maintained its functionality.
Vibration testing methods
Depending on the nature of the vibrations, there are three main testing methods:
- Sine vibration tests: continuous fatigue cycles are applied by amplitude and frequency. This kind of testing helps identify resonance frequencies in a part and determine its fatigue resistance capacity, but does not describe real environments.
- Random vibration tests: they simulate real environments. Fatigue cycles of variable magnitude are applied in a unpredictable pattern. Frequency is therefore used to define those magnitudes.
- Shock tests: They simulate the blows and impacts a part can receive and consist of shock pulses that are defined by acceleration, displacement and duration time.
At AIMPLAS, we have vibration equipment with a 335 mm diameter armature with which we can carry out these three types of tests: sinusoidal, up to 6 kN; random, up to 7 kN; shock, up to 12 kN (conditions subject to the weight of the test device).