Pamm 

About: Pamm is an academic journal published by Wiley-Blackwell. The journal publishes majorly in the area(s): Finite element method & Nonlinear system. It has an ISSN identifier of 1617-7061. Over the lifetime, 8262 publications have been published receiving 15713 citations. The journal is also known as: PAMM (Weinheim).

Introduction to Automatic Differentiation

Abstract: Automatic, or algorithmic, differentiation (AD) is a chain rule-based technique for evaluating derivatives of functions given as computer programs for their elimination. We review the main characteristics and application of AD and illustrate the methodology on a simple example.

Geometry + Simulation Modules: Implementing Isogeometric Analysis

Abstract: Isogeometric analysis (IGA) is a recently developed simulation method that allows integration of finite element analysis (FEA) with conventional computer-aided design (CAD) software [1,3]. This goal requires new software design strategies, in order to enable the use of CAD data in the analysis pipeline. To this end, we have initiated G+SMO (Geometry+Simulation Modules), an open-source, C++ library for IGA. G+SMO is an object-oriented, template library, that implements a generic concept for IGA, based on abstract classes for discretization basis, geometry map, assembler, solver and so on. It makes use of object polymorphism and inheritance techniques to provide a common framework for IGA, for a variety of different basis-types which are available. A highlight of our design is the dimension independent code, realized by means of template meta-programming. Some of the features already available include computing with B-spline, Bernstein, NURBS bases, as well as hierarchical and truncated hierarchical bases of arbitrary polynomial order. These basis functions are used in continuous and discontinuous Galerkin approximation of PDEs over (non-)conforming multi-patch computational (physical) domains. (© 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)

Identification of Microstructural Components of Bitumen by Means of Atomic Force Microscopy (AFM)

Abstract: Accounting for the large variation of asphalt mixes, resulting from variations of constituents and composition, and from the allowance of additives, a multiscale model for asphalt is currently developed at the Christian Doppler Laboratory for “Performance-based optimization of flexible road pavements”. The multiscale concept allows to relate macroscopic material properties of asphalt to phenomena and material properties of finer scales of observation. Starting with the characterization of the finest scale, i.e., the bitumen-scale, Atomic Force Microscopy (AFM) is employed. Depending on the mode of measurement (tapping versus pulsed-force mode), the AFM provides insight into the surface topography or stiffness and adhesion properties of bitumen. The obtained results will serve as input for upscaling in the context of the multiscale model in order to obtain the homogenized material behavior of bitumen at the next-higher scale, i.e., the mastic-scale. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

GetDP: a general finite-element solver for the de Rham complex

Abstract: GetDP is a high-level finite element solver using mixed elements to discretize de Rham-type complexes in one, two and three dimensions. This paper presents an overview of the structure of GetDP, highlighting the closeness between the organization of data defining a discrete problem and its symbolic mathematical description. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Applying TAF to generate efficient derivative code of Fortran 77‐95 programs

Abstract: This paper features FastOpt's automatic differentiation (AD) tool Transformation of Algorithms in Fortran (TAF), a source to source translator for programs written in Fortran 77-95. TAF and its predecessor TAMC have a long record of successful large-scale applications. Here we give an overview on how TAF approaches typical challenges of AD such as handling of badly written program code, of large memory/disk requirements, of iterative solvers or of black box routines. We also point out, where the user is required to prepare his program code prior to invoking TAF.