Session Details
MS15-1: Non-standard Formulations and Discretization Methods for Thin-walled Structures (Ganzes Minisymposium anzeigen)
Wednesday, 11. October 2017; 10:30 - 12:30 Uhr in Raum 7.01
Sitzungsleitung: Bastian Oesterle
10:30
Smooth spline spaces on unstructured quadrilateral meshes for isogeometric analysis (Keynote)
Hendrik Speleers (University of Rome "Tor Vergata"), Deepesh Toshniwal (University of Texas at Austin), Thomas J. R. Hughes (University of Texas at Austin)
Kurzfassung:
We present a framework for isogeometric analysis on unstructured quadrilateral meshes. Acknowledging the differing requirements posed by design and analysis, we propose the construction of a separate, smooth spline space for each, while ensuring isogeometric compatibility. A key ingredient in the approach is the use of singular parameterizations at extraordinary vertices. We demonstrate the versatility of the approach with applications in design and analysis.
Smooth spline spaces on unstructured quadrilateral meshes for isogeometric analysis (Keynote)
Hendrik Speleers (University of Rome "Tor Vergata"), Deepesh Toshniwal (University of Texas at Austin), Thomas J. R. Hughes (University of Texas at Austin)
Kurzfassung:
We present a framework for isogeometric analysis on unstructured quadrilateral meshes. Acknowledging the differing requirements posed by design and analysis, we propose the construction of a separate, smooth spline space for each, while ensuring isogeometric compatibility. A key ingredient in the approach is the use of singular parameterizations at extraordinary vertices. We demonstrate the versatility of the approach with applications in design and analysis.
11:10
Recent advances in isogeometric dual mortar patch coupling
Wolfgang Dornisch (University of Kaiserslautern), Joachim Stöckler (TU Dortmund University), Ralf Müller (University of Kaiserslautern)
Kurzfassung:
Isogeometric analysis fosters the integration of design and analysis by using the geometry description of the CAD system also for the numerical analysis. Hereby, the use of NURBS surfaces is common but entails the need for a coupling of non-conforming patches. The use of mortar methods allows a coupling which requires neither additional variables nor empirical parameters. In this contribution dual basis functions are used in order to obtain an accurate and efficient mortar method.
Recent advances in isogeometric dual mortar patch coupling
Wolfgang Dornisch (University of Kaiserslautern), Joachim Stöckler (TU Dortmund University), Ralf Müller (University of Kaiserslautern)
Kurzfassung:
Isogeometric analysis fosters the integration of design and analysis by using the geometry description of the CAD system also for the numerical analysis. Hereby, the use of NURBS surfaces is common but entails the need for a coupling of non-conforming patches. The use of mortar methods allows a coupling which requires neither additional variables nor empirical parameters. In this contribution dual basis functions are used in order to obtain an accurate and efficient mortar method.
11:30
Strain gradient elasticity theories in lattice structure modelling
Jarkko Niiranen (Aalto University), Sergei Khakalo (Aalto University), Viacheslav Balobanov (Aalto University)
Kurzfassung:
The first and second strain gradient elasticity theories, resulting in higher-order governing equations, are studied in the framework of continualization, or homogenization, of lattice structures such as trusses in plane and space, with auxetic metamaterials as a special application. In particular, the role of length scale parameters and classical dimensions, such as the beam thickness, is addressed by parameter studies. Finite element and isogeometric methods are utilized for discretizations.
Strain gradient elasticity theories in lattice structure modelling
Jarkko Niiranen (Aalto University), Sergei Khakalo (Aalto University), Viacheslav Balobanov (Aalto University)
Kurzfassung:
The first and second strain gradient elasticity theories, resulting in higher-order governing equations, are studied in the framework of continualization, or homogenization, of lattice structures such as trusses in plane and space, with auxetic metamaterials as a special application. In particular, the role of length scale parameters and classical dimensions, such as the beam thickness, is addressed by parameter studies. Finite element and isogeometric methods are utilized for discretizations.
11:50
A homogenization approach for beam-like structures with arbitrarily shaped and deformable cross-sections
Simon Klarmann (Technical University of Darmstadt), Friedrich Gruttmann (Technical University of Darmstadt)
Kurzfassung:
Beam elements demonstrate an efficient way of modeling large, thin structures if the assumed kinematics are reasonable. Regarding arbitrarily shaped cross-sections and varying material properties, difficulties arise in describing their behavior. A homogenization approach for a simple Timoshenko beam using a representative volume element circumvents this problem. In addition to that cross-sectional deformations can be taken into account.
A homogenization approach for beam-like structures with arbitrarily shaped and deformable cross-sections
Simon Klarmann (Technical University of Darmstadt), Friedrich Gruttmann (Technical University of Darmstadt)
Kurzfassung:
Beam elements demonstrate an efficient way of modeling large, thin structures if the assumed kinematics are reasonable. Regarding arbitrarily shaped cross-sections and varying material properties, difficulties arise in describing their behavior. A homogenization approach for a simple Timoshenko beam using a representative volume element circumvents this problem. In addition to that cross-sectional deformations can be taken into account.
12:10
Shell models in the framework of generalized continuum theories: isogeometric implementation and applications
Viacheslav Balobanov (Aalto University), Sergei Khakalo (Aalto University), Josef Kiendl (Norwegian University of Science and Technology), Jarkko Niiranen (Aalto University)
Kurzfassung:
Physico-mathematical models of shells in the framework of couple stress and strain gradient elasticity theories with variational formulations are developed. The models derived are embedded into a commercial finite element software as user subroutines following the isogeometric paradigm. Practical applications such as modelling of microarchitectured materials and materials with microstructure, or problems of fracture mechanics, illustrate the advantages of the non-classical continuum theories.
Shell models in the framework of generalized continuum theories: isogeometric implementation and applications
Viacheslav Balobanov (Aalto University), Sergei Khakalo (Aalto University), Josef Kiendl (Norwegian University of Science and Technology), Jarkko Niiranen (Aalto University)
Kurzfassung:
Physico-mathematical models of shells in the framework of couple stress and strain gradient elasticity theories with variational formulations are developed. The models derived are embedded into a commercial finite element software as user subroutines following the isogeometric paradigm. Practical applications such as modelling of microarchitectured materials and materials with microstructure, or problems of fracture mechanics, illustrate the advantages of the non-classical continuum theories.