FreeCAD - Mesh Regions for a Better Analysis |JOKO ENGINEERING|

Joko Engineeringhelp
8 Jun 202010:06

Summary

TLDRThis insightful video tutorial delves into the advantages and intricacies of meshing specific regions in FreeCAD to enhance analysis performance, paralleling experiences with SolidWorks. The presenter emphasizes how targeted meshing can dramatically reduce unnecessary computational effort while retaining desired resolution, especially in curved areas. Starting from scratch, the tutorial covers the creation of a basic 3D model, applying a directional force, and executing a G mesh analysis. The focus then shifts to demonstrating how creating mesh regions for specific faces can optimize processing time and improve analysis accuracy. This approach not only accelerates the meshing process but also offers a sharper resolution where it's most needed, showcasing practical visualization comparisons to underline the benefits of regional meshing in CAD design analysis.

Takeaways

  • 😀 FreeCAD's ability to perform meshing analysis can significantly improve performance and provide useful results.
  • 📊 Meshing in CAD software like FreeCAD, SolidWorks, Creo, or CATIA involves exponential processing scale, affecting analysis time and computational load.
  • 🌍 Specifying only specific regions for meshing can save substantial processing power while maintaining desired resolution, especially for curved areas.
  • 🖥️ In FreeCAD, using the part design workbench on the XY plane allows for the creation of detailed geometrical shapes like rectangles with symmetric constraints.
  • 🔧 Applying directional forces at angles in FreeCAD helps define the parameters for the Finite Element Analysis (FEA) workbench.
  • 📈 Precise meshing control, such as setting maximum mesh sizes, can optimize processing time and enhance the analysis's detail and accuracy.
  • 🛠️ Utilizing sub-mesh regions in FreeCAD can provide higher resolution where needed without excessive processing, showing a smoother transition from small to default mesh size.
  • 📐 Fixed geometries and applied forces in FreeCAD can simulate real-world conditions, aiding in a more accurate analysis.
  • 🔍 High-resolution meshing in targeted areas leads to better stress distribution and more accurate stress concentration identification in the analysis.
  • 📉 Visual comparisons in FreeCAD show the benefits of regional meshing for clearer and more detailed stress visualization.

Q & A

  • What is the primary focus of the video?

    -The video focuses on the benefits and effects of meshing a region while performing an analysis in FreeCAD, a 3D parametric modeling software.

  • Why is meshing important in CAD software?

    -Meshing is important because it helps in analyzing the performance of a design under various conditions, such as stress or displacement. It allows for a more accurate approximation of the physical behavior of the model.

  • How does the scale of meshing affect processing power?

    -The scale of meshing has an exponential impact on processing power. A finer, tighter mesh will require significantly more processing power and analysis time compared to a coarser mesh.

  • What is the advantage of specifying a region for meshing?

    -Specifying a region for meshing allows for targeted analysis, saving unnecessary processing power while still achieving the desired resolution in critical areas.

  • How does the video demonstrate the process of meshing?

    -The video demonstrates the process of meshing by creating a simple rectangular model in FreeCAD, applying a symmetric constraint, and then meshing the model with different settings to show the effects on resolution and processing time.

  • What is the significance of the curved surface meshing in the analysis?

    -Meshing a curved surface fundamentally involves approximation. The video shows that by using a sub-mesh region, one can achieve higher resolution in specific areas without significantly increasing the overall processing time.

  • How does the video compare the results of a standard mesh with a regional mesh?

    -The video uses visualization tools to compare the standard mesh, which has a uniform resolution throughout, with the regional mesh, which has higher resolution on specific faces. The comparison shows that the regional mesh provides a better approximation and more detailed results, especially in areas of high stress.

  • What is the practical application of the insights gained from the video?

    -The insights gained from the video can help engineers and designers optimize their CAD models for analysis, focusing computational resources on areas that require higher resolution, thus improving the efficiency and accuracy of their simulations.

  • How does the video address the issue of stress concentration in the model?

    -The video suggests that by adding a higher resolution mesh to areas where stress concentration is observed, one can better understand and potentially mitigate the effects of stress concentration on the model's performance.

  • What resources are provided for further exploration of the topic?

    -The video provides a link to a GrabCAD file where viewers can download and explore the meshed model further, allowing them to apply and test the concepts learned from the video.

Outlines

00:00

🛠 Meshing Analysis in FreeCAD and Its Benefits

This segment introduces meshing in FreeCAD, comparing it to SolidWorks to highlight the exponential nature of mesh processing across various CAD software. The narrator explains the process of creating a simple model and setting up a mesh analysis from scratch, emphasizing the importance of meshing specific regions to save processing power without sacrificing resolution, especially for curved surfaces. The process involves creating a model on the Part Design workbench, applying constraints, and using Gmesh for meshing. Despite a mesh error, the focus remains on demonstrating efficient meshing techniques to reduce processing time while maintaining high resolution in crucial areas.

05:01

🔍 Enhancing Mesh Resolution and Analysis Efficiency

In this part, the narrator continues with the FreeCAD demonstration by introducing a sub-mesh region to increase mesh resolution on a specific face of the model while keeping the rest of the mesh at default size. This technique is shown to significantly improve meshing speed and computational efficiency. Following this, fixed geometry and forces are applied to the model, and materials are specified for the analysis. The result set, displaying absolute displacement, demonstrates the advantage of targeted high-resolution meshing. Visual comparisons between general and regional meshing underscore better stress visualization and analysis accuracy. The video concludes by encouraging viewers to subscribe, promising more insightful content.

Mindmap

Keywords

💡Meshing

Meshing refers to the process of breaking down a geometric space into smaller, discrete elements, often for the purpose of analysis or simulation in engineering and design software like FreeCAD or SolidWorks. In the context of the video, meshing is essential for performing finite element analysis (FEA), allowing the software to approximate the behavior of materials under various conditions by examining these elements individually. The presenter discusses the significance of being able to specify mesh regions to enhance processing efficiency, especially when dealing with complex shapes or areas requiring high detail.

💡FreeCAD

FreeCAD is an open-source parametric 3D CAD modeler that allows for the design of real-life objects of any size. The video explores how FreeCAD supports meshing and FEA, which are typically features of high-end, proprietary software. By demonstrating meshing in FreeCAD, the presenter aims to show the software's capability for detailed and efficient analysis, comparable to that of industry standards like SolidWorks.

💡Exponential Processing

Exponential processing in the context of the video refers to the increase in computational effort and time required as the mesh resolution increases during an analysis. The presenter emphasizes that meshing, particularly in high-resolution settings, demands significantly more processing power, a characteristic common to CAD and FEA software. This concept underlines the importance of selective meshing to conserve computational resources.

💡Part Design Workbench

The Part Design Workbench in FreeCAD is a module or environment dedicated to creating 3D parts and components. In the video, the presenter uses this workbench to create a simple geometric shape as a basis for demonstrating meshing and analysis. This tool exemplifies the integrated approach of FreeCAD, allowing users to design parts and perform analyses within the same software.

💡Gmsh

Gmsh is a mesh generator software that is mentioned in the context of running a meshing operation in FreeCAD. Although not explicitly stated, the reference to 'G mesh' likely alludes to Gmsh or a similar meshing function within FreeCAD. Mesh generators like Gmsh are critical for converting geometric models into meshes, enabling numerical simulations.

💡Curved Surface Approximation

Curved surface approximation refers to the process of representing a curved surface using a series of small, flat elements (mesh). The video highlights the challenge of meshing across curved surfaces due to the inherent approximation involved. This is crucial for accurate analysis, as the quality of the mesh affects the fidelity of the simulation results, particularly in areas of high stress or complex geometry.

💡Mesh Region

A mesh region, as discussed in the video, is a specified area within a model where a different mesh density or size is applied, allowing for finer resolution where needed without excessively increasing the overall computational load. This technique is especially useful for focusing computational resources on areas of interest, such as zones with complex geometry or where high stress is expected.

💡FEA (Finite Element Analysis)

Finite Element Analysis (FEA) is a computational technique used to predict how objects react to external forces, vibration, heat, and other physical effects. The video demonstrates the use of FEA within FreeCAD, emphasizing its role in analyzing the designed model's response to applied forces by breaking it down into smaller, manageable elements (meshes).

💡Computational Power

Computational power in the context of the video refers to the capacity of a computer system to perform simulations and analyses, which is particularly relevant to the intensive processing required for detailed meshing and FEA. The presenter discusses strategies to optimize the use of computational resources, highlighting the balance between achieving detailed analysis and maintaining manageable processing times.

💡Stress Concentration

Stress concentration is a term used in the video to describe areas within a material that experience a significantly higher stress compared to surrounding areas, often due to changes in geometry such as sharp corners, holes, or notches. The presenter shows how using a finer mesh in these critical regions can provide a more accurate representation of stress distribution, which is essential for predicting failure points and designing safer, more reliable products.

Highlights

Introduction to meshing benefits and effects in FreeCAD, demonstrating its significant utility for analysis.

Comparison of meshing in FreeCAD with other CAD software like SolidWorks, CATIA, and Creo, emphasizing the exponential nature of mesh processing.

Explanation of the importance of specifying specific regions for meshing to conserve processing power while maintaining desired resolution.

Step-by-step guide to creating a basic model in FreeCAD using the Part Design workbench on the XY plane.

Demonstration of adding a directional force at an angle in FreeCAD for analysis purposes.

Introduction to the FEA (Finite Element Analysis) workbench in FreeCAD and starting a new analysis with a default mesh.

Troubleshooting a mesh error and proceeding with the analysis without delays.

Detailed explanation of meshing on curved surfaces and the need for approximation.

Using a sub mesh region to increase mesh resolution on a specific face while keeping processing time low.

Visual comparison of standard meshing vs. using a mesh region for higher resolution where needed.

Applying fixed geometry and forces in the analysis to simulate real-world conditions.

Discussion on material specification in the analysis, using steel as an example.

Presentation of analysis results, focusing on the improved resolution and computational efficiency achieved through regional meshing.

Visualization of stress distribution and the impact of higher mesh resolution on understanding stress concentration areas.

Encouragement to explore further by providing a link to download the FreeCAD file used in the demonstration.

Transcripts

00:00

in this video let's go over the benefits

00:02

and effects of meshing a region while

00:05

doing an analysis in free cab

00:07

this surprised me I learned that freecad

00:10

was able to do this it's a very very

00:12

event thing and it's very very useful I

00:16

will show some footage here hopefully

00:19

remember to edited of doing a quick

00:23

meshing analysis in SolidWorks this was

00:26

a video to help improve the performance

00:29

of SolidWorks and the findings are

00:32

meshes and meshing related processing is

00:34

really exponential in scale this should

00:37

not be a surprise and this should also

00:40

apply to freecad processing mesh is

00:43

going to be exponential no matter how

00:45

you slice it it doesn't matter if you're

00:47

in creo SolidWorks CATIA you know freak

00:50

adding anything will have an exponential

00:53

scale when processing you mesh that

00:55

means if I go to do a tight mesh in my

00:58

analysis I'm gonna take exponentially

01:01

more processing so if we can only

01:04

specify a specific region to mesh we can

01:08

save a whole lot of unnecessary

01:10

processing power and still get the

01:11

resolution we're looking for this is

01:14

particularly true for curved regions so

01:17

why don't we get started and I'm gonna

01:18

go do this from scratch so you can

01:20

follow along if you prefer and the part

01:23

design workbench on the XY plane I can

01:26

make a rectangle I can add and what my

01:30

background makes things kind of visible

01:32

so let me change it my preferences to

01:36

display colors color gradient apply and

01:40

we'll use the symmetric constraint to

01:43

make sure that we are centered here and

01:46

I'm going to use a shift H for a

01:49

horizontal dimension we're going to go

01:51

three inches wide shift V for a vertical

01:53

and two inches tall and we're going to

01:58

do that did not go to the center like I

02:03

will intended grab those two and combine

02:07

those points shift R for radius

02:10

quarter inch radius seventy-five clothes

02:16

will pad it's one inch tall so there is

02:21

a model I want to add a directional

02:23

force like I've done in the last video

02:26

this time we'll do it at an angle so it

02:29

takes three points to define a plane so

02:35

plane to find I can sketch on this and

02:38

we'll do something like in fact I'll

02:41

import this corner and I'll do something

02:51

like a four angle we can establish now

02:55

you listen like twenty five degrees

02:58

I'll make this four inches close that

03:03

and hide my plane so let's go back to

03:11

the FAA workbench and from here I'll add

03:17

in some basic constraints I'll start a

03:20

new analysis and we'll run a G mesh I'm

03:25

going to simply apply a default mesh but

03:30

and that did not seem to work I forgot

03:33

one thing

03:34

unless actually do this I'm going to

03:36

highlight my body or my pad here and now

03:40

say G mesh and now it's made a match

03:43

that's a that's a lot better we have a

03:45

measure era

03:46

fortunately I'm going to keep on going

03:47

so you can see the rest without any

03:53

delay so there's our standard mesh but

03:57

this is a curved surface and meshing

03:59

across the curved surface fundamentally

04:01

means approximation you need to

04:04

approximate if it's a curved surface so

04:06

one of the options for meshes is I can

04:08

of course say the same woman at my mesh

04:11

to be a maximum size of 50,000 remesh

04:15

this and you can see it's taking time to

04:19

calculate this in free cab to calculate

04:22

a 50,000 that

04:25

you know just a lot more processing and

04:29

when I go to run the analysis it's going

04:31

to be a lot more analysis time so we

04:33

we're finally done we have a small

04:34

mesh and that's you know that's one way

04:41

to do it but that just took a long time

04:44

so what I'm going to do is let my pad

04:47

gene match we're going to mesh at a

04:52

regular amount and now if I highlight my

04:56

mesh here I had the option for creating

05:01

a mesh region so I can add a face and

05:08

choose all the mesh on that face is

05:11

going to be 50 sow in inches okay so

05:17

I've added this sort of sub mesh region

05:20

if I show my mesh nothing has changed

05:22

right but now that I have this sub mesh

05:24

region I can double click and say apply

05:27

and now we're meshing at fifty thousand

05:30

space and a default measure there where

05:32

else and you can see that the mesh goes

05:37

from small back to its default size

05:40

quite smoothly this gives us more

05:43

resolution where we care about having

05:45

more resolution but we've mesh much

05:47

faster than faster than last time and we

05:50

have still a reasonable amount of

05:52

computational power it's a way that we

05:54

can get the resolution we want without

05:56

going up that exponential curve I can

06:01

finish this study out I'll hide this

06:04

mesh and start adding a few things maybe

06:06

I can add in some fixed geometry here

06:12

and I'll add in a force acting on this

06:16

face let's go with let's go with that

06:20

and make this nine fifty or some number

06:24

like that well specify a direction and a

06:30

reference to this face reverse it

06:34

all right so that's our analysis thus

06:38

far in fact you know what

06:40

instead of this face let's do this

06:44

the circular face here putting the face

06:46

on where we have a lot of that

06:47

definition now I can specify material I

06:51

like calculate steel we're doing

06:53

imaginary examples okay and it looks

07:00

like we're ready to run so I actually

07:05

don't quickly calculates all right the

07:07

InP

07:11

run calculates all right so we've got a

07:15

result set and you can see if I do my

07:25

absolute displacement I can hide this

07:28

body we have a very high resolution of

07:31

computation on our round face and our

07:34

smooth flat faces that probably don't

07:36

require as much are less so does this

07:43

bias anything are we better off with a

07:46

machining region then with the generic

07:49

machinist so how much let's do a little

07:52

bit of visual visualization with this so

07:56

first off I will take a look at some

08:00

images that I've compiled so if I use

08:03

the pipeline visualization tool and

08:05

freecad there you can see on the left

08:10

without using regional mission there's

08:13

default mesh all the way through and

08:15

basically what we've made on the right

08:17

and you can download this file from my

08:18

grab CAD and the link in the description

08:20

if you want to check it out further we

08:23

have much better definition especially

08:24

looking at stress down here the stress

08:28

appears to go much higher than with a

08:31

higher resolution it sounds like you

08:34

have a better approximation and scaling

08:36

as well so that's strength and if we

08:40

take a look at a result mesh you know

08:44

higher definition this looks actually

08:46

quite similar

08:47

but when you come down to stress you can

08:49

see we have a far different scale of

08:52

stress and you can see what you think of

08:55

as a large stress being dispersed across

08:59

his face is really a stress

09:01

concentration at this face right so

09:04

having a higher resolution on this face

09:07

would be a great argument for adding a

09:11

measure to disperse the stress like a

09:13

fill it where is this it appears the

09:15

stress is going a lot more through the

09:17

face and this is just what they look

09:20

like displaced and that looks quite

09:21

somewhere between the two pictures so

09:24

you can't get a lot better visualization

09:26

results through this looks like I'm

09:29

already past 10 minutes so I'm going to

09:31

call this video hope this video is

09:32

helpful if it was please subscribe and

09:34

I'll see you

09:35

[Music]