# Parametric Model

FEM-Design provides a module for workflows and projects where the geometry of the structures are similar but differ mainly in their major parameters and  dimensions. The Parametric Model module delivers solutions for quickly entering and modifying typical structures.

So, Parametric Model is an editor module, where you can create parameterized models as templates for later use in FEM-Design 3D Structure module.

Contents:

## Access

Click the Parametric Model command button on FEM-Design startup dialogue.

## The scope

The following structural and load objects can be applied for building-up parameterized structural frame-, shell- or complex-systems:

FEM-Design's "templates" folder contains several parametric model examples to use and practice the definition and input methods.

## Parameterizing tools

The Parameter tab gives the tools for setting up variable parameters (numbers and geometric parameters) and for assigning them to the modeling objects:

### Base rays and planes

Base rays and Base planes can be used as the frame structure of a parametric model. Structural analytical objects and loads can be attached to them.

Base planes are recommended for parameterization of spatial 3D structures, while Base rays are recommended for parameterization of directions or planar 2D structures (sections and frame standings).

An example for defining Base planes and Base rays:

• The Base planes define the planes where
• the Point supports and the Columns will be placed,
• the bottom and the top level, and the first and last plane of the roof structure will be.

• The Base rays define the axis x’ direction of the Beams (and for locking, see later Locks).

### Grids

Grids are used to create iterative patterns like a series of columns or an array of point foundations.

With Grid we can create 1D (line), 2D (planar) or 3D grids and meshes:

Structural and load objects can be attached to a Grid (system). The attachable objects should fit in one cell of the Grid; we can place an object anywhere in a cell, and it will be attached to its host Grid.

Grid can be warped in every possible way by its corner points.

If a Grid cell is triangular, objects cannot be attached to its triangular edges.

By directions, we can set the number of Grid cells by giving numbers (e.g. 2) or Integer-type parameters, and set where we want to multiply objects within the Grid.

We can also set that the local y’ axis of the grid-assigned object should follow the grid direction and position changes or should keep its original direction.

### Locks

Locks are used to bound nodes of objects, base lines and Grids to the intersections of Base objects. If the Base objects move, the locked objects are moving with them. The locked objects are marked with the lock symbol in the model space.

Intersections can be defined by two base lines, a base line and base plane, or three base planes. The following figure shows an example of how to lock the endpoint of an inner Beam to the intersection of Base plane and Base ray.

### Constraints

With Constraints we can define fixed numerical or parametric distances between parallel Base objects.

The following figure shows an example of named parametric Constraints defined as distances between Basic planes.

### Parameters

With Parameter we can control the parametric model, and later - in 3D Structure module - we can set the final structure with their values. A new parameter (integer or real) can be defined in the dialogue of Parameter tool or during Grid and Constraint creation.

If one of the parameters (which are assigned to the parametric model) change, the modifications will be automatically applied to the parametric model.

Example 1

Example 2

Example 3

## Insert parametric model to 3D Structure projects

We can insert a parametric model (saved to file with name and .prm extension) in our currently open 3D Structure project with the following commands:

• Tools > Apply parametric model...
• Edit > Paste file...

After opening a .prm file, we can finalize the values of the available parameters in an upcoming the dialogue, and place the fixed size model in the model space.

Parent topic: Import / Export Model