ANSYS WORKBENCH 14

ANSYS WORKBENCH 14.0

1 Cristóbal Jesús Valdepeñas Octavio

Name: Cristóbal Jesús Valdepeñas Octavio Year: 3º Ingeniería Mecánica Escuela de Ingenieros Industriales de Albacete, UCLM. Introduction course to finite elements engineering with ANSYS Workbench.



EXERCISE 1

1:

In this practice, we will use the design software SolidWorks to generate the structure on the image. After that,

we will import it with the ANSYS module called “Design Modeler” in “IGS” format, the one which ANSYS is able

to read.

Besides, taking use of the big quantity of possibilities that the program has, we will test the structure with some

kind of analyses, like the linear buckling or the modal module, seeing the stresses and the deformations.

Mostly in huger structures, in many occasions, simplifying will be one of the most useful things we can do to

make the calculations faster. To prove this, we will turn our 3D model to shells clicking on “Mid Surface” and we

will transform the sections of our structure in lines, and the volume in shells. In addition, if the detail level we

want to get is not too skilled, we could draw our porch in “Beam” elements, making them very simple and the

calculations faster (just a line between two points and a cross section).

GEOMETRY DRAWING AND IMPORTING. As we are going to see in the images below, we have sketched our structure up with SolidWorks, following the

IPE and HEB dimensions.



Once we have both types of bar we are going to need, the next step is opening the assembly window.



Now, we have made our structure in an external CAD program so we have to import it in ANSYS. Saving the file

with ANSYS compatible format, “IGS”, we have to click on import file with an external CAD, and we will see

something like this:

Going back to the Project screen, we have the materials definition left to do, so we go to Engineering Data,

duplicate the Structural Steel we find on the window and assign a number to the Tensile Yield Strength and

Compressive Yield Strength of each material.



TEST WITH THE 3D GEOMETRY As far as the geometry and material definition is done, we start the Mechanical, define the contacts we have

between our elements and the supports with the ground.

After that, seeing the forces we have in the exercise, putting them on the structure is as easy as clicking on

force, assign the face where it is going to be acting and write the coordinates of the vector that will define the

force we are using.



If we want to know the stresses of the structure and the total deformations, we have to put those analysis in the

solution folder.



Now we can compare results with other kind of programs because we have what we were looking for, numbers,

deformations, stresses and the behavior of the current structure. But this is not all because we haven’t

considered that our porch can suffer linear buckling or vibrations (can remember the Tacoma bridge, which

went away with a very slow wind).

LINEAR BUCKLING: This kind of module will help us to know what the buckling is like. In order to know a determinate number of

possibilities, in Analysis settings we can say how many options we want to get. In our case, we have chosen two

(just not to calculate less common ways of buckling), as we can see below.



If we choose the directional deformation, we could see which direction is going to be analyzed.



MODAL: Vibrations in our model may be one of the points that we have to get under control, knowing the frequency in

which the structure could have serious problems. In ANSYS, we have to add another environment to the static

structural we were doing at first:

Going to the solutions, the stresses or the deformations are not as useful as in the static structural were because

here we do not have forces, just the rigid matrix and the support conditions (they could be optional, but if we

define them, we would go to more specific ways of vibrations).



The more important results we have from this is the following paragraph with the summary.

SHELL SIMPLIFICATION As we said, the program gives us options to simplify geometries. For example, if we want to analyze our porch

with shells, going to the Design Modeler, selecting Mid Surface and being careful with some aspects:



Going to the Mechanical and defining again the loads and the supports with the ground, the results we get are

showed in the next image.



As we can see, the stresses and the deformations are almost the same, but the time that the program has spent

to calculate the whole structure has been shorter in the shell one.

BEAM SIMPLIFICATION Opening a new Static Structural environment, defining the material properties and creating points with the

Design Modeler, we define “lines from points” to represent the directrix of the bars that compose our porch.

If we keep defining the forces and the supports, we will get the same results.



Exercise 2:

2

GEOMETRY As we practiced how to create a new geometry, transform it to shell and beam and put many loads in it, we are

going to make a little experiment. In the first case, we are going to study the assembly as an ideal piece, without

welding. In the second case, we are going to add two prisms with triangular base to emulate the welding we

have not put on the first case to see which are the differences.

Case 1: Making the object described in the image with SolidWorks:

Importing to ANSYS’s Design Modeler:



Loading the forces in the hole of the vertical piece:

It could have been done with the “bearing load” which charges a load produced by a cylindrical object that goes

through that hole.



Case 2: Adding the triangular base prisms to the piece:



Conclusion: as we can see if make zoom to the place of the piece that join one part with the other, the strains

are higher in the piece without the welding:



(Red arrow with the worst strain)

This exercise could be simulated with shells, but as the objective we had was to see the differences between the

welded piece and the other and we cannot create the welding as a line or a shell in a very precise way, we chose

the 3D analysis. Anyway, the result of clicking on Mid Surface and connecting both faces un the first case:



EXERCISE 3

3

This analysis will be useful to compare the effects of designing the structure with revolute joints or rigid joints.

CASE 1: JOINTED STRUCTURE

GEOMETRY Building the structure with linear elements:



STRAINS AND DEFORMATIONS:

Writing the material characteristics, putting on the structure de loads and charging the supports, we get those

results, which ones are not too difficult to obtain after the first and the second exercises done.



CASE 2: FIXED STRUCTURE

GEOMETRY This test is very fast because we only have to change the kind of joints that we want to use in this part of the

Mechanical:

After that, clicking on solving, we get the new solutions of our loaded structure so we can compare both cases:



At first, we were hoping to get different results, but as we can see, the two horizontal bars are continue so it is

supposed to have bending moments in both cases. If these bars were not continue, in the jointed structure

would have just axial forces.



DEFORMATIONS

JOINTED STRUCTURE FIXED STRUCTURE

AXIAL FORCES

JOINTED STRUCTURE FIXED STRUCTURE

At the end of this exercise, we needed to see what happened with the 3D structure so we sketched it in Solid

Works and made an analysis in ANSYS workbench. That moment was when we noticed that sometimes we need

to simplify our model in order not to spent almost ten minutes calculating a little structure like this one.



3D MODEL

The results differ more than in the other solutions, but we suppose that it is because of the geometry and the

support conditions we have written.



CONCLUSSIONS:

The course has been useful because I have learnt how to use two programs on the same time. One of them has

been the Workbench, which was the main object of the lessons. The other has been the design software of Solid

Works. I did not have any idea about how to use one or the other but I could spend hours and hours

investigating about their working.

After having taken five lessons of four hours each, it seems to have been too short, but the course has opened a

lot of possibilities. In my opinion, once we know how to use the main options and the basic commands of a

software, you just have to look for exercises on the internet or simply satisfy the need of feed our curiosity.

Thermal analysis

ANSYS WORKBENCH 14

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Transcript of ANSYS WORKBENCH 14