Stress bicycle chain

[NDO]

1. The problem statement, all variables and given/known data

See attachment for the problem. or visit the link http://i908.photobucket.com/albums/ac286/NDO_02/Capture.jpg

Basically calculate the stress in the pin and the link in a bicycle chain.

2. Relevant equations

the average shearing stress = P/A = F/A
i think the chain is made of 2 shearing stresses

F.S = ultimate stress/ allowable stress

3. The attempt at a solution

Can someone help. I have no idea where to start. can someone give me a pointer

cheers NDO

[uart]

Your attachment is not yet approved but it looks like one of your class mates has reposted the exact same question here : http://www.physicsforums.com/showthread.php?t=347571

Perhaps a moderator should merge these two threads.

You should both start by :

1. Finding an expression for the tension force in the chain as a function of the crank length, sprocket radius and pedal load.

2. Find the cross sectional area of both the pin and the link at it's overall narrowest point (make sure you include the pin hole when finding the narrowest point).

Do the above and the problem should be fairly straight forward.

BTW. What grade/subject course work is this?

[NDO]

first year uni

mechanics

[NDO]

with the cross sectional area of the link

do u just calculate it using the width between the links which is the narrowest part or should i use the area around the hole for the pin or should i treat it as a composite shape

cheers
NDO