The causes include exposure to repetition, force, awkward postures, contact stress and vibration.
2.
As can be seen, there is a contact stress where the spheres actually touch.
3.
Burnishing may occur on any sliding surface if the contact stress locally exceeds the yield strength of the material.
4.
If this were not the case, the contact stress of a load being transferred through a point contact would be infinite.
5.
In the absence of surface friction, contact stresses are normal ( i . e . perpendicular ) to the contact surface.
6.
Pile on more spheres and the contact stresses increase, to the point of causing frictional instability ( dynamic friction ), and perhaps failure.
7.
With a single drive wheelset, the Herzian contact stress between the wheel and rail necessitated the largest diameter wheels that could be accommodated.
8.
Wear debris is bad because it is relatively large compared to the surrounding surface finish and thus creates more regions of high contact stress.
9.
Health problems such as carpal tunnel syndrome would be covered, as well as other ailments related to repetitive motion, force, awkward postures, contact stress and vibration.
10.
The regulations are aimed at preventing carpal tunnel syndrome, tendinitis and other health problems associated with repetitive motion, awkward postures, contact stress and other on-the-job conditions.