# Caxman Innovation Shop

### 3.11 Iso-geometric Analysis Tool (IGATools++)

### 3.11 Iso-geometric Analysis Tool (IGATools++)

Trimmed isogeomemtric volumes is a new technology that brings the ideas of surface trimming in CAD into tri-variate isogeometric modelling, thus breaking free from the block structures of untrimmed isogeometric volumes. Potentially this can be part of a next generation tri-variate CAD-kernal.

**IGATools** is a modernly designed general purpose Isogeometric Analysis (IGA) software library. Its main purpose is to numerically solve Partial Differential Equations (PDEs) using the IGA paradigm.

The library is implemented in C++17, its design is object oriented with extensive use of generic programming techniques (a.k.a. *templates metaprogramming*).

Some of its features are:

- Dimension independent code through the use of templates;
- Computational efficiency;
- Multi-threading capabilities (through the use of the Intel TBB library);
- Support of Hierarchical BSpline and NURBS basis;
- Support of trimmed geometries;
- Extensive and automatic test suite;
- Defensive programming.

In the CAxMan project the IGAtools library was extended in the following ways, obtaining a new version, that we call IGATools++:

- a module (in the form of a library) is now present to provide interoperability with the SINTEF’s GoTools library. In particular, the GoTools’ univariate, bivariate and trivariate splines (trimmed or not) are now loadable and usable in the igatools framework;
**[GoTools]** - a preprocessor (based on the GoTools library) is developed that takes as input a GoTools 3D trimmed geometry and gives as output a repametrization of the trimmed Bezier elements, that is needed to build any IGA-based solver;
- a 3D linear elasticity solver is available. This solver can use also 3D trimmed geometries when a reparametrization of the underlying trimmed Bezier elements is available (see the point above).

#### Information

CaxMan D2.1 Requirements Design for Additive Manufacturing

CaxMan D2.2 IGA based shape represntation (initial)

CaxMan D2.3 Analysis tool for AM, linear setting

CaxMan D2.5 Analysis for AM, non-linear setting

(a) Paper: M. Sebastian Pauletti, Massimiliano Martinelli, Nicola Cavallini, and Pablo Antolin. Igatools: An Isogeometric Analysis Library, SIAM J. Sci. Comput., 37(4), pp. 465–496, 2015.

(b) Paper: P. Antolin, A. Buffa, F. Calabrò, M. Martinelli and G. Sangalli. Efficient matrix computation for tensor-product isogeometric analysis: The use of sum factorization, Computer Methods in Applied Mechanics and Engineering Volume 285, pp. 817–828, 2015.

(c) Paper: N. Cavallini, O. Weeger, M.S. Pauletti, M. Martinelli, and P. Antolin. Effective Integration of Sophisticated Operators in Isogeometric Analysis with igatools, Lecture Notes in Computational Science and Engineering, Volume 107, pp. 209-230, 2015.

#### Extend

IGA-Tool Download PageGitHub License - Information

#### Additional Information

Originator: Massimiliano Martinelli (CNR-IMATI)Technology Readiness Level: 4

Environment: 2 SaaS