> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ntop.com/llms.txt
> Use this file to discover all available pages before exploring further.

# How to create a Simulation Model

## Objective:

Learn what a Simulation Model is and how to create one.

## What is a Simulation Model?

A **Simulation Model** brings together all of the necessary elements for the part to be analyzed, whether in simulation, optimization, or further analysis. A **Simulation Model** is built up of **Domains** and Connectors. There are several different types of domains depending on the type of simulation being performed. Most domains contain an input body type and **Attributes**, while the **Lattice Domain** only requires a **Material** instead of an **Attribute**. Connectors are made up of **Tie Constraints**, **Structural Bonded Contacts**, or **Thermal Bonded Contacts** that allow the analysis of multiple domains. A **Simulation Model** does not need a connector to run if it only has one FE Mesh. If it has multiple domains, there will always be one less connector compared to the total number of domains.

| **Model:**       | **Domain Type:** | **Body Input:**                  | **Attribute:** |
| ---------------- | ---------------- | -------------------------------- | -------------- |
| Simulation Model | Lattice Domain   | Lattice                          | N/A            |
| Lattice Domain   | Lattice Mesh     | N/A                              |                |
| Fluid Domain     | Implicit Body    | Fluid Attribute                  |                |
| Solid Domain     | FE Mesh          | Beam/Point/Shell/Solid Attribute |                |

## Procedure:

**1. Define a Material:** The Simulation Model needs a Material block to assign properties to the part. nTop has some preset common materials available, or you can build your own Isotropic or Orthotropic Material.

* Add the **Isotropic Material** block.
* Add an Isotropic Material Property by double-clicking in the Property input.
* Add the **Isotropic Linear Elastic Property**and enter the following values:
  * Young's modulus: 2.21e+13 Pa
  * Poisson's ratio: 0.3

![A gif example showing how to create a material using the Isotropic Material block](https://files.learn.ntop.com/help-articles/structures/41632543887379.png)

**2. Add a Solid Domain and Material Attributes:** This step assigns the material properties to the mesh. Attributes define the material, thickness, frame, and region in which it occurs. Three types of Attributes can be chosen: Solid, Beam, and Shell. Each type allows for the selection of different elements.

* Add a **Solid Domain** block and insert your **FE Mesh** into the Mesh input ([from this tutorial](/help-articles/knowledge-base/meshing-workflows/how-to-create-an-fe-volume-mesh)).
* Double-click in the Attributes input and add a **Solid Attribute**.
* Drag the Material from the last step into the Material input.

![A gif example showing how to create a Solid Domain using an FE Volume Mesh and the Isotropic Material that was created in step 1](https://files.learn.ntop.com/help-articles/structures/41632569380371.png)

**3. Create a Simulation Model:** The last step is to add a **Simulation Model** block. In this example, we are using only one domain, so we don't need to expand the Domain list. Drag and insert the **Solid Domain** from the last step into the Domain input. For this example, we will be leaving the [Connectors](/help-articles/knowledge-base/structures/methods-for-connecting-multiple-fe-meshes-in-an-simulation-model) empty.

![A Simulation Model created using the Solid Domain](https://files.learn.ntop.com/help-articles/structures/41632569382931.png)

And that's it! You've successfully created a Simulation Model.

Are you still having issues? Contact the [support team](https://support.ntopology.com/hc/en-us/requests/new), and we'll be happy to help!

You can move on to [the next article](/help-articles/knowledge-base/structures/how-to-select-boundaries-using-boundary-by-body) in this series and learn how to select regions of an FE Mesh.

## Download the Example file:

* [Example File](https://files.learn.ntop.com/Support%20Article%20Example%20Files/Knowledge%20Base/Simulation/Simulation%20Model%20Example.ntop)

## Keywords:

*FE Material analysis simulation lattice property create beginner model finite element fluid optimization constraint solid attribute isotropic material component tie set up connector attributes starting domain*