mibsuhsnuja
New member
- Aug 12, 2018
- 3
First of all, sorry if this is the wrong place to post. Since it is related to fatigue testing machine rather than fatigue, I posted here instead of structural (general).
I need to create a fatigue testing machine to test a bike chassis. Hydraulics and pneumatics are complex (for accurate control) and bit expensive. So I have been thinking of a setup of crank slider mechanism.
** Setup of what I am thinking**
The whole setup (motor and crank slider) is mounted on a adjustable base whose height can be adjusted. The crank displaces the work piece by certain displacement to generate stress. The load cell is attached to the slider which measures the force. The adjustment of adjustable base height is automatically controlled based on reading of load cell.
**
I feel crank slider would be far easier to fabricate (IDK I might be wrong also. Correct me if so) and cheaper also for this setup. It seems like a reasonable option considering I am mainly focused on stress ratio of 0.
The major confusions are:
[ol 1]
[li] Is crank slider fatigue testing machine a good option for doing fatigue analysis of stress ratio '0' instead of hydraulic/pneumatic rig?[/li]
[li]I am worried about impact of crank slider and swingarm which provides different result than seen in real life.
[/li]
[li]I think testing just stress ratio of 0 is okay and I don't need to test -ve stress ratios. Correct me here also if I am wrong.[/li]
[/ol]
Any suggestions including what possible major challenges that I can face are welcome.
I need to create a fatigue testing machine to test a bike chassis. Hydraulics and pneumatics are complex (for accurate control) and bit expensive. So I have been thinking of a setup of crank slider mechanism.
** Setup of what I am thinking**
The whole setup (motor and crank slider) is mounted on a adjustable base whose height can be adjusted. The crank displaces the work piece by certain displacement to generate stress. The load cell is attached to the slider which measures the force. The adjustment of adjustable base height is automatically controlled based on reading of load cell.
**
I feel crank slider would be far easier to fabricate (IDK I might be wrong also. Correct me if so) and cheaper also for this setup. It seems like a reasonable option considering I am mainly focused on stress ratio of 0.
The major confusions are:
[ol 1]
[li] Is crank slider fatigue testing machine a good option for doing fatigue analysis of stress ratio '0' instead of hydraulic/pneumatic rig?[/li]
[li]I am worried about impact of crank slider and swingarm which provides different result than seen in real life.
[/li]
[li]I think testing just stress ratio of 0 is okay and I don't need to test -ve stress ratios. Correct me here also if I am wrong.[/li]
[/ol]
Any suggestions including what possible major challenges that I can face are welcome.
