SA45: Matrix Displacement Method: Introduction

[@yijielu7681]

Explains everything perfectly!!! I need this tutorial soooooo much since the final exam is coming!!! I'm so confused about this stiffness method...Please upload more!!

[@RaunySilva]

Why didn't I find this video earlier? It is a gem 👏👏👏

[@gideonchonia8146]

excellent delivery

[@ineverlickyoghurtlid3903]

Thank you so MUCH!! I have learnt so much from your channel!

[@DrStructure]

You are so welcome!

[@seyfiyigitsahin1471]

I think, your and your team's place is already selected in the heaven :D

[@TingSiiYu]

truly our brain savior.

[@braverucabral2443]

Is the best, I have learned a lot from your video.. May you make tutorials about Structure dynamics calculation ? Please

[@khondokarabuzafor865]

Plz make tutorials on strength of materials.It will help us a lot .

[@derrickmaina3202]

I was also wondering is there an elaborate calculation explaining how we simplify the force equations while coming up with the shear equations? ( equations 3 and 4)

[@AnasQiblawi]

You are the best ever

[@AK--if1su]

Hi doc. I have a huge issues with stiffness matrix for a truss. Especially one that has a support that settles by a specific amount. I've asked around and read many text books yet no example from which to follow. Please upload a video with a truss that has settlement of a support if you've encountered anything of that nature. Thanks!

[@lalitajoshi5350]

EXCELLENT!!

[@elyashivbokobza2500]

thank you so much this is excelent

[@kirolousyoussef8609]

is this the same as the direct stiffness method?

[@DrStructure]

Yes!

[@abhishekaggarwal6834]

Pls tell how to create such beautiful animations? i want to create videos for other subjects

[@DrStructure]

Adobe illustrator + Camtasia Studio + VideoScribe

[@abhishekaggarwal6834]

@@DrStructure Pls see if you can cover Rcc and steel subjects also. People are in great need of it.

[@mechatronicsninja3806]

thank you .I'm wondering what software did you use to do the voice and the video ?

[@DrStructure]

This is not a computer-generated voice, it is natural human voice. We used Camtasia Studio to compile the final video.

[@mechatronicsninja3806]

@@DrStructure Thank you so much for these information

[@DrStructure]

You're welcome.

[@eng.saalim8646]

Dr structure, I need finite element analysis lectures. Please help us. And what is the difference btn it and matrix displacement method

[@DrStructure]

The finite element method is a more general version of the matrix displacement method. Here we are dealing with simple (one dimensional) elements used in trusses and frames. The FEM uses two dimensional (surface) elements such as triangles and rectangles, three dimensional (solid) elements like a cube, as well as one dimensional elements for modeling structural systems. But the computational strategy/method used in FEM, in principle, is the same as the one used in the matrix displacement method.

[@AnasQiblawi]

Can you do Rainforecd Concrete tutorials

[@DrStructure]

Yes, eventually we will get to design topics including Steel and RC.

[@magnusrobinson8735]

Please please do. Thank you so much for the great videos you make.

[@raheelmalook5884]

What is degree of freedom? Please explain

[@DrStructure]

In some structural analysis techniques such as the displacement method, we model the behavior of a structural member (such as a beam or a column) using two or more joints. For example, it is common to describe the behavior of a beam in terms of its end joints. Once we determine the forces at the joints, then we can determine the forces (shear and moments) within the member. In two dimensional space, each joint in a structure can move (has the freedom to move) in x and y directions, and it can rotate about the z axis. These (the displacements and rotation) are called the degrees of freedom of the joint. The degrees of freedom of a structure is that of its joints.

[@kirolousyoussef8609]

video on how to solve the matrix using the gaussian elimination method??

[@DrStructure]

We don't have any lectures on the Gaussian Elimination Method, since it is more of a math (numerical analysis) topic than a structural analysis one. You should be able to find ample resources online, or offline, that present solution of linear system of equations using Gaussian Elimination or other relevant methods.

[@candela2213]

Where are those lectures?? SA27 and SA33

[@DrStructure]

SA27: kzbin.info/www/bejne/Y5C0dpuve9qlf6M SA33: kzbin.info/www/bejne/q5OTY5eqa9mWrs0

[@niruda638]

Slope Deflection method and Displacement method same or not ???

[@DrStructure]

No, the two methods are not the same, the names cannot be used interchangeably. However, the displacement formulation can be derived from the slope-deflection equations, hence the two methods are related at some basic level.

[@phamtuanhiep6204]

What app do you use for this video?

[@DrStructure]

Adobe Illustrator and Camtasia Studio.

[@phamtuanhiep6204]

Thank you!!!

[@hoshangmustafa9672]

I solved the matrix @12:35 using Gaussian elimination method. The minus sign doesn't appear with my solution.

[@DrStructure]

You must have left out a negative sign somewhere in the process. If you wish, you can use the (free) online course (see link in the video description) to communicate with us. There, you can post your solution for feedback.

[@Dustmadeout]

So it's basically a Finite Element Method for 1D beams. At least it looks like it.

[@DrStructure]

Yes, this method is a version of the finite element method. Here, we are using a one-dimensional element to model the system.

[@aaronvillajuan9060]

why is the reaction at B 7wL/4, it's not in equilibrium. thank you.

[@DrStructure]

The shear force just to the left of B is acting in the downward direction at B with a magnitude of 3wL/4. The force just to the right of B is also acting downward with a magnitude of wL. Therefore, the reaction force at B must be 3wL/4 + wL = 7wL/4 in the upward direction. As for the force equilibrium for the entire beam, we have a downward reaction force of 3WL/4 at support A, an upward reaction force of 7wL/4 at support B, and a downward applied load of wL. They do add up to zero.

[@pachecogomezfrandiop]

Dr what's your bibliography please

[@DrStructure]

There are many structural analysis textbooks available on the market. No specific one however has been used for creating the content of these videos.

[@AnasQiblawi]

I love you

[@moyeenkhan826]

Please make a video about influence line for indeterminate structure

[@mertgokgoz4073]

At 2:20 , why wasnt the Vji shown downwards, in a manner that would negate the effect ofMji in other words. Can anyone explain in to me? As oppose to what was done in kzbin.info/www/bejne/q5OTY5eqa9mWrs0 5:33 on this video?

[@DrStructure]

Generally, we draw the internal forces in a member in the assumed positive direction when we are not sure what direction the force actually assumes. For example, when we don’t know the direction of a shear force, when the force is unknown, we assume it to be downward (at the right end of the segment) since that corresponds to a positive shear in the beam. The sign of the calculated force tells us if we made the correct assumption. If the calculated value is positive, then our assumption was correct. If however the sign is negative then we know that the direction of the force is opposite to what was initially assumed. In this case, we placed the shear force (Vji) in the upward direction since given that the distributed load is being applied to the segment is downward, the chances are that both end shear forces are going to be upward. So, we placed the shear force in that direction. But of course we could have also placed the force in the downward direction, which would have resulted in a slightly different equation, one in which the sign for Vji would have been different,

[@mertgokgoz4073]

@@DrStructure thank you for your reply!