Re:Breaks Observed in Rover Wheel Treads
by JetDogRush on Wednesday March 22, 2017 @09:21AM
(#13930647)
There are two major factors - fatigue (think bending a paper clip repeatedly) due to driving over tons of small rocks, and the the mechanics of having six wheels contributing additional damage to the front and middle wheels. Think of pushing a rolling suitcase versus pulling one - when hitting an obstacle it tends to dig in instead of easy popping up. The front and middle wheels are in front of their pivots, and so tend to get driven in to rocks by the other wheels.
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Re:Breaks Observed in Rover Wheel Treads
by mnw21cam on Wednesday March 22, 2017 @09:54AM
(#13930860)
In terms of metal fatigue, aluminium doesn't last very long at all. That's one reason why you want electric cables made of copper, not aluminium.
Re:Breaks Observed in Rover Wheel Treads
by JetDogRush on Wednesday March 22, 2017 @10:16AM
(#13931047)
True! The actual induced strain is not particularly high (the wheels do not visibly deform) but it's the cycle count that will get you. The chevron-shaped grousers also act as stress concentrators, which is why the cracks are all starting at those tips.
Re:Breaks Observed in Rover Wheel Treads
by mtreis86 on Wednesday March 22, 2017 @07:21PM
(#13936002)
So the rear wheels are on trailing arms, but the front and middle are leading arms, which increase the incidence angle by the angle of the arm in regards to ground? So impacting a 45degree slope would have the force of say 55 degrees, as the arm is ten below level? The trailing arm would then impact that same slope at effectively 35 degrees.
Just trying to understand their conclusions.