# Catia Fea

Topics: Materials science, Finite element method, CATIA Pages: 19 (4341 words) Published: May 31, 2011
FEA Tutorials
Releases 12 & 13

CATIA V5

University of Windsor

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SDC

CATIA V5 FEA Tutorials

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Copyrighted Chapter 2 Material Analysis of a Bent Rod with
Solid Elements

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CATIA V5 FEA Tutorials

Introduction

In this tutorial, a solid FEA model of a bent rod experiencing a combined load is created. No planes of symmetry exist and therefore simplifications cannot be made. Finally, the significance of the von Mises stress in design equation is discussed.

1 Problem Statement

Clamped end

The bent rod, shown to the right, is clamped at one end and subjected to a load of 2000 lb as displayed. The steel rod has a Young modulus of 30E+6 psi and Poisson ratio 0.3 . The nominal dimensions of the rod are also displayed below. Although this problem is more efficiently handled with beam elements, we propose to use solid elements. There are two types of solid elements available in CATIA V5: linear and parabolic. Both are referred to as tetrahedron elements and shown below. Tetrahedron Elements

5 in 1 in 8 in

linear

The linear tetrahedron elements are faster computationally but less accurate. On the other hand, the parabolic elements require more computational resources but lead to more accurate results. Another important feature of parabolic elements is that they can fit curved surfaces better. In general, the analysis of bulky objects requires the use of solid elements.

parabolic

Cross sectional Radius is 1 in

2 Creation of the Part in Mechanical Design Solutions
Enter the Part Design workbench which can be achieved by different means depending on your CATIA customization. For example, from the standard windows

toolbar, select File > New . From the box shown on the right, select Part. This moves you to the part design workbench and creates a part with the default name Part.1.

Analysis of a Bent Rod with Solid Elements

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In order to change the default name, move the curser to Part.1 in the tree, right click and select Properties from the menu list. From the Properties box, select the Product tab and in Part Number type wrench. This will be the new part name throughout the chapter. The tree on the top left corner of the screen should look as displayed below.

From the tree, select the XY plane and enter the Sketcher

. In the Sketcher, draw a

, and dimension it . In order to change the dimension, double click on the circle dimension on the screen and in the resulting box enter radius 1. Your simple sketch and the Constraint Definition box used to enter the correct radius are shown below.

Leave the Sketcher

. . Draw the spine of the bent

From the tree, select the XY plane and enter the Sketcher

and dimension it to meet the geometric specs. In the Sketcher, rod by using Profile the spine should match the figure below on the right. Upon leaving the Sketcher shown below.

, the screen and the tree should be as

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CATIA V5 FEA Tutorials

You will now use the ribbing operation to extrude the circle along the spine (path). Upon selecting the rib icon , the Rib Definition box opens. Select the circle (Sketch.1) and the spine (Sketch.2) as indicated. The result is the final part shown below. Regularly save your work.

3 Entering the Analysis Solutions

From the standard windows tool bar, select

Start > Analysis & Simulation > Generative Structural Analysis There is a second workbench known as the Advanced Meshing Tools which will be discussed later. The first thing one can note is the presence of a “Warning” box indicating that...