New drop test facility for the impact assessment of portable devices

In 2015 Simpact decided to build their own drop test facility so that they could carry out their own impact testing in-house and offer this impact evaluation method to their clients. This month saw the first commercial use of the facility for the drop test evaluation of mobile phones. It can be fully instrumented and features a linear system that guides the device to be tested to the impact surface. This allows one to accurately replicate a load case which may be detailed in a standard such as the transit drop procedure described in the US Department of Defence standard MIL-STD-810G.

Devices can be dropped from a range of drop heights up to 2.2 m. A carriage with low friction bearings is mounted to the linear slide and supports a drop arm on the end of which the device is attached via suction cups. By making use of two rotating mounts at the end of the arm, devices can be orientated and dropped at any angle. A mechanical clamp and release mechanism allows for a smooth and consistent release.

The suction within the cups holding the device is provided by a venturi valve. This is powered by a compressor and in the terminal phase of the drop, just before impact, the carriage activates a micro switch that instructs the venturi valve to supply an overpressure to the suction cups. This provides a clean release of the device and at this point, the carriage and drop arm is then brought to a stop by two energy absorbing dampers. The device is then fully detached and at the same orientation when the impact takes place.

A micro switch triggers the instrumentation. Devices can be dropped onto any type of impact surface. This includes a transparent impact surface which allows for a high speed camera view (using a front face mirror) of the impact from the underside. 

The following instrumentation is available for use with the facility;

• Two Photron® FASTCAM SA1.1 high-speed cameras. Set-up to trigger together and acquire full resolution at 5400 frames per second (fps).
• Four Simpact ICARUS® LED lights giving a combined output of 28,000 lumens.
• Two single axis accelerometers (2000 and 6000g) suitable for the drop testing of consumer products (Measurement Specialities model 64b, weight 1 gram)
• One DEWESoft® SIRIUS data acquisition system (for the above accelerometer)
• Two Laptops for the high speed cameras and the data acquisition

Please contact Simpact if you would like to find out more. Below are some images of the facility. In the high speed video area of our website (CAE Tools) you will find some example videos of a Nokia mobile phone being dropped from 2m.