# C12. More about solid elements

#### **C12. More about solid elements**

The principles stated for 2D modeling remain applicable in 3D, in particular, the use of isoparametric elements (parallelepipeds rather than tetrahedrons) is preferable, which requires a heavy and rigorous preparation of the basic geometry.

Automatic meshers should be used with caution.

<span style="text-decoration: underline;">Example of a bridge deck modeled using solid FE:</span>

![](https://lh4.googleusercontent.com/Tr_jY2_b066Y_RKTt5F2jibK0tZGkyTcdIbcx2uBEg19S8HmgLS-GlSwHJI4NdhT1xvIhUTIiaNmUi0ycLhnOxpr-jlSMg5SSEP1LBlRtDQ4aYJg8zdONdbJGjSg7d0rfPfMxJa9EsNu93vQfQyPQQ)

![](https://lh3.googleusercontent.com/n8LjXHaJw7PFAmBIV6aQlIB9u7mt9NictNb-NZ8GZ5XgMneBJjTQaVKpshsd4WpTv-F5PMJwx2vaZ06hDLkn7D_1S9rhecVW6dYuei5yLFQTaBZCgCbb_H5Ulpb5svgNN-JYZwc4i-30T3sb58a-9g)

  
(Taken from Part 3 - [**Example C - Modeling of girder grids**](https://wiki.afgc.asso.fr/books/finite-element-modeling-and-computations-in-the-field-of-civil-engineering/page/example-c-beam-grillage-modeling "Example C - Beam Grillage Modeling")).