Recent content by havsula

I have thought about that, but my problem is that k (curvature) is a part of the differential equation. The only way around that is to chose a EI(s) that to not vary at s=0. But maybe the shooting method can work for me, since I can guess on a k(0)

Hello Okay I see that. It is only that if somebody says that a method works, I feel plain stupid (and maybe I am) if I cannot solve it in the same way. But I still do not have a boundary condition for the fourth equations: ∂k/∂s=−1/EI(s){k*dEI/ds+F*sin(pL+a−p} So still a little stucked.

Hello I have finally found out what my main problem is: I have manage to set up the whole system for a beam divided into N+2 parts. Have onle set up the equations on the interior points 1 ot N. But I do not have enough boundary conditions to set up the system. For each differential equation f...

Thank you man. Now I have a lot of thing to read:)

Sorry everybody. I wrote down the equations a little to fast. But here they are again, in proper latex:) These equation is for large deflection of a flexible beam of length L. I have got them from an article and trying to figure out how to solve them. In the article they state that they have...

Hello I have a system of differential equations: dx/ds = sin(p) dy/ds=cos(p) dp/ds = k dk/ds = -1/EI(s)*(k*dEI/ds+f*sin(p)) x(0)=y(0)=p(0)=p(L)-pl = 0 These are nonlinear differential equations. I should use some sort of nonlinear finite difference. But I do struggle to setting up the finite...

I can put up the equations for the three springs if I have assumed that they are the part of the same system. But in order to try to explain: As I can see the system it looks like that. Only the bolt have a physical connection between the upper and lower part of this system. So how can the...

Hello But what I do not understand is how the stiffness of the clamps will add to the stiffness of the system These forces pulls in each direction, the green lines is in some way the where the force will act in my head. There are no physical connection between the clamps so I cannot see that...

Hello I really struggle with understand how and why bolted jonts actually works: The following figure copied from http://ocw.mit.edu/courses/mechanical-engineering/2-72-elements-of-mechanical-design-spring-2009/lecture-notes/MIT2_72s09_lec10.pdf shows a bolted joint: After the bolt is...

Will it be correct to do if there is a force F(x,t) which works along the whole length of the beam (also the differential element)?

Yes I can see that it is the same equation. The F should be the constant force applied to the end. Do I not need to add it? Is it no possible to look at this as "forced vibration"? or will the boundary condition take care of that constant force? I beginning to understand that it is a lot of...

First one question. In all references I have found the variable in the wave equation is displacement (normally written as u). But in your equation you have written ε, which most often is used for strain. What is ε in your equation: Will this be correct: Is it possible to look at the constant...

Yes, I have come to that conclusion. Now I only have to figure out how these equation look like. Will be back when I have something:)

Yes that is true. With ##x_1(0)=0## and ##x_2(0) =L ## we got: ##\xi(t) = {m_2L\over m_1+m_2} {1\over 2} + \frac{F}{(m_1+m_2)}t^2## But now I have to find out how to get from this, to the position of ##x_1## and ##x_2## as a function of time. Have to think..

Agreement Witherspoon that. But how to solve it. How will the differential equation look like?