Isogeometric analysis and hierarchical refinement for multi-field contact problems


Book Description

The present work deals with multi-field contact problems in the context of IGA. In particular, a thermomechanical as well as a fracture mechanical system is considered, where novel formulations are introduced for both. The corresponding discrete contact formulations are based on a variationally consistent mortar approach adapted for NURBS discretized and hierarchical refined surfaces. Finally, the capabilities of the proposed framework are demonstrated within numerous numerical examples.




Isogeometric Analysis and Hierarchical Refinement for Multi-field Contact Problems


Book Description

The present work deals with multi-field contact problems in the context of IGA. In particular, a thermomechanical as well as a fracture mechanical system is considered, where novel formulations are introduced for both. The corresponding discrete contact formulations are based on a variationally consistent mortar approach adapted for NURBS discretized and hierarchical refined surfaces. Finally, the capabilities of the proposed framework are demonstrated within numerous numerical examples. This work was published by Saint Philip Street Press pursuant to a Creative Commons license permitting commercial use. All rights not granted by the work's license are retained by the author or authors.




Non-standard Discretisation Methods in Solid Mechanics


Book Description

This edited volume summarizes research being pursued within the DFG Priority Programme 1748: "Reliable Simulation Methods in Solid Mechanics. Development of non-standard discretisation methods, mechanical and mathematical analysis", the aim of which was to develop novel discretisation methods based e.g. on mixed finite element methods, isogeometric approaches as well as discontinuous Galerkin formulations, including a sound mathematical analysis for geometrically as well as physically nonlinear problems. The Priority Programme has established an international framework for mechanical and applied mathematical research to pursue open challenges on an inter-disciplinary level. The compiled results can be understood as state of the art in the research field and show promising ways of further research in the respective areas. The book is intended for doctoral and post-doctoral students in civil engineering, mechanical engineering, applied mathematics and physics, as well as industrial researchers interested in the field.







Multi-field modeling and simulation of fiber-reinforced polymers


Book Description

This work proposes a new numerical approach for analyzing the behavior of fiber-reinforced materials, which have gained popularity in various applications. The approach combines theories and methods to model the fracture behavior of the polymeric matrix and the embedded fibers separately, and includes a modified plasticity model that considers the temperature-dependent growth of voids. Tests are conducted to explore different types and sequences of failure in long fiber-reinforced polymers.




EAS Elements for Solid Mechanics - Mesh Distortion Insensitive and Hourglassing-Free Formulations with Increased Robustness


Book Description

Proposed in the early 1990s, the enhanced assumed strain (EAS) method is one of the probably most successful mixed finite element methods for solid mechanics. This cumulative dissertation gives a comprehensive overview of previous publications on that method and covers recent improvements for EAS elements. In particular, we describe three key issues of standard EAS elements and develop corresponding solutions.




Inverse dynamics of underactuated flexible mechanical systems governed by quasi-linear hyperbolic partial differential equations


Book Description

This work is about the inverse dynamics of underactuated flexible mechanical systems governed by quasi-linear hyperbolic partial differential equations subjected to time-varying Dirichlet boundary conditions that are enforced by unknown, spatially disjunct, hence non-collocated Neumann boundary conditions.




Characterisation and modelling of PC/ABS blends


Book Description

The present work deals with the characterisation and multi-scale modelling of the large-strain response of ternary polymer blends. In a homogenised constitutive modelling approach, particularly the deformation behaviour featuring plastic dilatancy is investigated. Concerning the micromechanical modelling, constitutive models are proposed for the blends' individual phases and compared regarding their capabilities to capture the composition-dependent fracture toughness in unit cell models.




Thermodynamically consistent space-time discretization of non-isothermal mechanical systems in the framework of GENERIC


Book Description

The present work addresses the design of structure-preserving numerical methods that emanate from the general equation for non-equilibrium reversible-irreversible coupling (GENERIC) formalism. Novel energy-momentum (EM) consistent time-stepping schemes in the realm of molecular dynamics are proposed. Moreover, the GENERIC-based structure-preserving numerical methods are extended to the context of large-strain thermoelasticity and thermo-viscoelasticity.




Numerical methods for the inverse dynamics simulation of underactuated mechanical systems


Book Description

The present work deals with the inverse dynamics simulation of underactuated multibody systems. In particular, the study focuses on solving trajectory tracking control problems of differentially flat underactuated systems. The use of servo constraints provides an approach to formulate trajectory tracking control problems of underacutated systems, which are also called underactuated servo constraint problems.