# Homework Help: Dynamics help: Find structural stiffness and maximal displacement under half sinewave load

1. Nov 7, 2014

### Gogeta_2

1. The problem statement, all variables and given/known data
1. A structure with weight of 100 kN and which has a natural period of 1 second.
Compute the stiffness of the structure. The structure has 5% critical damping. The
structure when at rest is subjected to a half sine wave loading having a magnitude of
10kN and lasting 2 seconds. Find the maximum displacement of the structure and the
time at which it occurs. Take the acceleration of gravity as 10 m/sec2.

2. Repeat question 1 above using the approximate solution treating the impulse as a very
short duration loading where the duration of the impulse is 0.1 seconds.

2. Relevant equations

3. The attempt at a solution
I have no idea how to start, if someone can just give me steps to follow that would be appreciated.

Last edited: Nov 7, 2014
2. Nov 7, 2014

### Staff: Mentor

Welcome to PF!

Can you give us more background? is this an architectural or structural engineering course?

The question seems pretty specialized.

3. Nov 7, 2014

### Gogeta_2

Thanks!
This question is based on the dynamics of structures under earthquake loading.

4. Nov 7, 2014

### Staff: Mentor

It helps when we understand where you are at in your studies. Thats why there's the relevant equations section of the template.

Are you using MATLAB or some other engineering tool?

I found this set of course slides that talk about the theory. There maybe something there that will get you started:

http://www.ct.upt.ro/users/AurelStratan/dsis/en-curs01_dsis.pdf [Broken]

Also have you checked with other students or your book surely there are related problems.

Last edited by a moderator: May 7, 2017
5. Nov 7, 2014

### Gogeta_2

I am at graduate level, we can use MATLAB to solve this, however, this question does not require the use of MATLAB.
Thank you for your post I will check the slides out.
The book hasn't got a similar related problem which is why I don't know how to start

Last edited by a moderator: May 7, 2017
6. Nov 7, 2014