So, good morning everyone. Welcome to our last day of IFEM, so to say.

Today we will have two tutorials and we will consider exercise 14, which is an exercise very close to the setup of an examination.

And we will discuss this in about three hours here, and the scheduled time to do such questions in the examination would be one and a half hours.

So, of course we have plenty of time to discuss things, but to give you an idea how long you should need for solving such a task.

Okay, let us consider exercise 14.1. There we have given a one-dimensional problem with a system as sketched here.

So, we have a truss with a truss stiffness of EA and it is clamped on either side.

And we have a distributed load N of X with a maximum of N naught in the middle of the truss.

And there is a strong form given together with the boundary conditions and these are the questions here.

And I ask you to read all these individual tasks and to put together some notes how you would approach these tasks.

And I think five minutes should be a good time for you to put that all together.

So, the first task is to derive the weak form. Okay, there you can note down what the individual steps are.

And for the remaining questions, this is much about computation.

There I ask you to write down what maybe basic equations you need and how to solve that.

In the examination, you can use a handwritten formula consisting of either six pages DIN A4 single-sided or three pages DIN A4 double-sided.

And maybe you have already prepared something like that.

Otherwise, I ask you to have a look to either the lecture notes or the recapitulations to put together the relevant equations here.

So, let's say five minutes and then we go through that step by step.

Okay.

Okay.

Okay.

Okay.

Who needs more time? More time?

Ah, okay. Yeah, it would have been to put together the individual steps necessary to solve the equation. Sorry for that.

Okay, so then let's put that together. What is necessary to derive the weak form?

What is necessary to derive the weak form?

I would say every one of you, one after the other says some aspect. So, what do we need?

This is already given.

The residuum, okay.

So, we need the residuum.

What is the, let me just write down what is the residuum here?

U of x?

Sorry, I did not get it.

Yes, ah, yeah, yeah. Yeah, okay.

It's zero, yeah, but what is the residuum?

Yeah, but what is the residuum in particular here?

EAU

Equals zero.

It should be zero. Yeah. Exactly. So, I put here like this. It should be zero. Okay.

Next, what do we need next?

One after the other. So, second one. Yeah.

Test function?

Okay.

Later, first it belongs to the space test.

And later.

Okay.

So, maybe we can,

what is the test function space? V, maybe the next one.

Yes, yes, that's true. V of zero is zero and V of L is zero. Yes.

And now there is some empty space here.

Yes.