Finite element analysis of stresses in civil engineering objects, such as concrete slabs, requires high quality meshes, preferably quadrilateral, since they have significant advantages over triangular meshes, especially in terms of accuracy of results obtained at the FEA stage itself. The simplest way a meshing task can be formulated is "to generate a mesh inside user-defined closed sequence of line segments". But in reality the problem is significantly more complex, due to the following fact: a real-life model always contains at least one or several additional features processing of which ultimately compsises up to 90% of the actual program code size. Here are just several of possible features:

• internal opening(s) of various shapes;
• internal and/or boundary points that in FEM models correspond to places where external forces or constraints are applied; such points are often surrounded by zones where large stress gradients normally appear, and therefore very fine mesh must be generated in such zones in order to provide trustworthy evaluation of stresses and strains;
• model boundaries, internal and/or external, may consist of a variety of different entities, at least line segments and/or arcs;
• inside the domain there can also be large variety of line segments, arcs and their complexly connected combinations, not necessarily comprising closed sequences, but arbitrarily shaped instead;
• real-life meshes may contain hundreds of thousands or even more quadrilaterals, sometimes making it impossible or too long to generate a mesh in reasonable time;
• the user may also wish the program to automatically evaluate initially imposed requirements for desirable step size along each entity, should those sizes turned out to be inadequate; for example, too large.

QUAD-BUILD also allows the user to select several additional options such as:

• generation of QUAD8 and QUAD9 elements;
• generation of large-sized elements inside the domain, thus minimizing the total number of elements;
• automatic renumbering the model nodes, with the goal of minimization of the stiffness matrix bandwidth later at the FEA stage.

Over several years, our company developed a series of quadrilateral mesh generators that would cover one or several of the additional features listed above. The new product QUAD-BUILD 5.0 is significantly more powerful than the earlier ones, because it provides complete support to all of those features. It is applicable to many areas of engineering that require finite element analysis: mechanical engineering, electronics, structural engineering, to mention just a few. Below we provide an example of mesh generated by QUAD-BUILD 5.0 for a typical concrete slab with internal openings. We invite you to contact us if you would like to obtain more examples or need additional information; there are also more complex examples here. Our contact details are placed at the end of this page.

Example: Concrete slab with internal line segments and openings..

Delivery, licensing and support.

QUAD-BUILD 5.0 was completely developed by our company and contains no third party code. We wiil provide you with full, one-off commercial licence and free support for 12 months. If you purchase QUAD-BUILD 5.0 , you will be provided with:

- complete, fully commented source code in ANSI C;

- User Manual containing detailed description of input and output data structures and an example driver program;

- and a graphical visualisation program QUAD-PRO. It allows displaying original domains that are to be meshed, as well as generated quadrilateral meshes. 

Finally, our "try-before-you-buy" policy. If you send us several examples of your domains, we will run QUAD-BUILD 5.0 on them and send you the meshes created. If you are satisfied with results, you can then purchase QUAD-BUILD 5.0.

We invite you to contact us, preferably by e-mail . We can also help with other mesh generation, computational geometry and general finite element analysis needs.

Computational Mechanics Australia Pty. Ltd.

PO Box 736
Camberwell South , VIC, 3124
AUSTRALIA
Ph.: + 61-3-9809-0814
Fax: + 61-3-9809-0843
E-mail: comecau@bigpond.com