# III. Data File Preparation

## A. Introduction

This chapter describes the generation of an ATILA data file, except for the information about theelements described in Chapter IV. Automatic generation of an ATILA data file is available using the MOSAIQUE code. This generation is described in Part II.

A data file includes three different sections:

- Header
- Mesh (nodes, elements, geometric properties, materials, analysis parameters, etc.)
- Boundary conditions.

All data, except the angles, must be given in MKS units orany coherent unit system deduced from the MKS system. The angle values mustalways be given in degrees.

In this chapter, we always refer to a simple illustrative example and give the corresponding entries and data sets. Thisexample is the modal analysis of an axisymmetrical Tonpilz transducer,radiating in water. This transducer is made up of two ceramic rings, a tailmass, and a head mass. The structure, its material properties, and thecorresponding mesh are described on the following two pages.