Fatigue test on bicycle frame
Purpose of the test
To test the fatigue strength of welds made on the aluminum frame of an electric folding bicycle for urban use.
It was necessary to perform the test following the requirements in terms of the number of cycles and constraint conditions described in the UNI EN ISO 4210-6 standard.
As per the specific request of the client, the minimum applied load was to be 100 N while the maximum load was to be set at 1200 N.
The cyclic stress was applied with a frequency of 10 Hz.
Approach and Solution
For the test set up, the following were used:
- strict constraints
- A trolley constraint as described in the relevant legislation
- A pneumatic actuator with a 10 kN load cell, connected to a dedicated control unit and programmed to work in force control
Results
- Monitoring and recording displacement trend corresponding to the applied load.
- Software detection of any breakage developed during the test, caused by exceeding the set displacement limits.
Finally, before the fatigue test and at the end of the stipulated number of cycles (500,000), the welds were inspected using the liquid penetrant technique for cracks or crazing.