Customer
In order to prove the mechanical resistance of their products, our client, a French manufacturer of sporting goods, asked us to design and build a resistance test bench accessible to the general public.
Tested product
Backpack
A storage container that can be carried on a person's back.
Objective
Testing the resistance of backpacks to an impact from a 0.25m fall.
Problematic issues
The impact test bench must be easy to use, ergonomic and aesthetically pleasing as it is intended to be installed in a shop as a demonstration bench. The tests carried out and the measurements displayed must be easy to understand for an uninformed public. However, it must reproduce the same test conditions as in a laboratory.
Solution and result
The backpack demonstration bench designed by LF Technologies combines mechanical performance and attractive industrial design.
The bag under test is attached to the chest of a mannequin and weighed down with 5kg. The bust is attached to a vertical translation axis and activated by an electric jack.
A cycle is performed as follows:
- The electric cylinder raises the bust to the programmed "drop" height (250 mm). This rise is done at a slow speed so as not to cause any stress on the bag due to acceleration/braking.
- The electric cylinder pulls the bus down with an acceleration corresponding to gravity. This simulates a free fall of the bust, bringing it to a vertical speed of 2.1 m/s for a "drop" of 250 mm.
- The electric actuator brakes the torso abruptly, simulating an impact of the torso on the floor.
The bench is equipped with a PC in order to program the cycles and visualise in real time the speed curves, measurements, displacement, etc. The software has been designed to be used by non-experts. The user only has to select a pre-set form (drop height, frequency, number of cycles) and start the test.
The demonstration test bench, located in the shop, is a guarantee of the quality of the backpack. It directly demonstrates the reliability of the products marketed to end consumers.
