×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Help with Timoshenko theory of elastic stability

Help with Timoshenko theory of elastic stability

Help with Timoshenko theory of elastic stability

(OP)
In trying to continue my education past my Bachelor's, I'm using my lunch time at work to sharpen the saw, so to speak.  I acquired a copy of Timoshenko's Theory of Elastic Stability and am currently working through Chapter 1 in an attempt to expand my knowledge base.  I have noticed that in the text, the authors often skip through a small mountain of math to give either the intermediate or final answer.  If you are naturally gifted or have someone teaching this to you, I don't suppose that's too bad; however, that is not the boat I've caught.  

Specifically, my question is on Ch. 1, page 5.  At the top of the page, the authors are solving for the undetermined coefficents in the differential equation by noting that the left and right sides of beam under the load 'Q' have common slopes and deflections.  No problem there, but i am getting tripped up on the math.  First, I assume that the second equation is the derivative of the first relationship with respect to 'c'.  Now, if I do that, I don't understand how the -Qc(l-c)/Pl term becomes +Q(l-c)/Pl in the second equation.  I'm also struggling with the solution for parameter 'D'.  

Could somebody point this hapless soul in the right direction?  I have run around this thing so many times that I've lost the capability of novel thought. All help is appreciated.

Thanks.

RE: Help with Timoshenko theory of elastic stability

(OP)
OK, I kept plugging and got parameters B & D - something to be said for good bookkeeping.  But I still get tripped up with the relationship at the top of pg. 5; I still don't see how the -Qc(l-c)/Pl in eq. 1 becomes +Q(l-c)/Pl in eq. 2.  

RE: Help with Timoshenko theory of elastic stability

(OP)
Never mind, I figured it out.  Sorry to bother everybody.

RE: Help with Timoshenko theory of elastic stability

ChooChoo - Well Done.  I'm glad to see your persistence rewarded

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources