Fall 2012 ME 395 - GSI Josh Lacey

This is a discussion forum for Josh Lacey's lab sections of Fall 2012 ME 395.
HomeHome  CalendarCalendar  FAQFAQ  SearchSearch  MemberlistMemberlist  UsergroupsUsergroups  RegisterRegister  Log inLog in  

Share | 

 Yield stress of aluminum

Go down 
GSI Overlord

Posts : 126
Join date : 2012-08-30

PostSubject: Yield stress of aluminum   Fri Oct 05, 2012 3:01 pm

When you are all calculating the yield stress of aluminum from the tensile test that we did, there are two things I want you to keep in mind:

1) I mentioned this in lab, but in case anyone forgot, you can just use the same diameter of the aluminum cylinder as we used for the brass cylinders last week when you are converting from load to stress...nominally they are machined to the same dimensions.

2) When you are finding your yield stress, I want everyone to quote the yield stress with a 0.2% offset. This means you will NOT report the 'classical' yield stress at the inflection point of the stress strain curve, but rather you have to draw an offset line that starts from 0.2% strain on the x-axis and is drawn up to intersect the stress-strain curve with a slope equaling the elastic modulus. The intersection of the offset line and the stress-strain curve will give you the yield stress with a 0.2% offset. Make sure in your report when you mention the yield stress you found that you are quoting yield stress with a 0.2% offset. Because aluminum doesn't really exhibit much in the way of work hardening and the curve stays quite flat after yielding, you'll find the 'classical' value and the 0.2% offset will be pretty close, but I want everyone to follow what is considered 'standard operating procedure' in industry when quoting properties of materials. After all, everyone's report is a reflection of an industry standard test for fracture toughness, so we might as all be as rigorous as possible.
Back to top Go down
View user profile http://fall2012me395.forumotion.com
Yield stress of aluminum
Back to top 
Page 1 of 1
 Similar topics
» Just a suggestion for MC/SISIP that may ease there work load and at the same time reduce some stress on all VETS
» Revleft: A basically liberal website
» Post-traumatic stress an injury, not a disorder, veterans say
» Chemtrails Exposed By Pilots, Doctors, & Scientists. Soil & Water Tested High In Aluminum & Barium

Permissions in this forum:You cannot reply to topics in this forum
Fall 2012 ME 395 - GSI Josh Lacey :: Lab Questions :: Lab 4-
Jump to: