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Phase-field modeling reformulates fracture problems as energy minimization problems and enables a comprehensive characterization of the fracture process, including crack nucleation, propagation, merging, and branching, without relying on…

Computational Physics · Physics 2025-04-15 Elham Kiyani , Manav Manav , Nikhil Kadivar , Laura De Lorenzis , George Em Karniadakis

A Newton-type active set algorithm for large-scale minimization subject to polyhedral constraints is proposed. The algorithm consists of a gradient projection step, a second-order Newton-type step in the null space of the constraint matrix,…

Optimization and Control · Mathematics 2021-01-12 William W. Hager , Davoud Ataee Tarzanagh

The phase field approach to modeling fracture uses a diffuse damage field to represent a crack. This addresses the singularities that arise at the crack tip in computations with sharp interface models, mollifying some of the difficulties…

In this manuscript, the phase-field fracture irreversibility constraint is transformed into an equality-based constraint using the slack variable approach. The equality-based fracture irreversibility constraint is then introduced in the…

Numerical Analysis · Mathematics 2022-02-22 Ritukesh Bharali , Fredrik Larsson , Ralf Jänicke

The phase-field model for fracture, despite its popularity and ease of implementation comes with its set of computational challenges. They are the non-convex energy functional, variational inequality due to fracture irreversibility, the…

Numerical Analysis · Mathematics 2022-06-24 Ritukesh Bharali , Fredrik Larsson , Ralf Jänicke

In this work, we consider pressurized phase-field fracture problems in nearly and fully incompressible materials. To this end, a mixed form for the solid equations is proposed. To enhance the accuracy of the spatial discretization, a…

Numerical Analysis · Mathematics 2022-09-21 Seshadri Basava , Katrin Mang , Mirjam Walloth , Thomas Wick , Winnifried Wollner

We propose a feasible active set method for convex quadratic programming problems with non-negativity constraints. This method is specifically designed to be embedded into a branch-and-bound algorithm for convex quadratic mixed integer…

Optimization and Control · Mathematics 2015-12-09 Christoph Buchheim , Marianna De Santis , Stefano Lucidi , Francesco Rinaldi , Long Trieu

In this paper we present an active-set method for the solution of $\ell_1$-regularized convex quadratic optimization problems. It is derived by combining a proximal method of multipliers (PMM) strategy with a standard semismooth Newton…

Optimization and Control · Mathematics 2023-03-01 Spyridon Pougkakiotis , Jacek Gondzio , Dionysios S. Kalogerias

Irreversible evolution is one of the central concepts as well as implementation challenges of both the variational approach to fracture by Francfort and Marigo (1998) and its regularized counterpart by Bourdin, Francfort and Marigo (2000,…

Numerical Analysis · Mathematics 2019-07-24 Tymofiy Gerasimov , Laura De Lorenzis

The purpose of this work is the development of space-time discretization schemes for phase-field optimal control problems. Specifically in the optimal control minimization problem, a tracking-type cost functional is minimized to steer the…

Optimization and Control · Mathematics 2022-09-14 Denis Khimin , Marc C. Steinbach , Thomas Wick

This paper presents a novel implicit scheme for the constraint resolution in real-time finite element simulations in the presence of contact and friction. Instead of using the standard motion correction scheme, we propose an iterative…

Distributed, Parallel, and Cluster Computing · Computer Science 2023-06-13 Ziqiu Zeng , Hadrien Courtecuisse

Fixed-point or Newton-methods are typically employed for the numerical solution of nonlinear systems arising from discretization of nonlinear magnetic field problems. We here discuss an alternative strategy which uses local Quasi-Newton…

Numerical Analysis · Mathematics 2024-09-11 Herbert Egger , Felix Engertsberger , Lukas Domenig , Klaus Roppert , Manfred Kaltenbacher

In recent years, various means of efficiently detecting changepoints in the univariate setting have been proposed, with one popular approach involving minimising a penalised cost function using dynamic programming. In some situations, these…

Methodology · Statistics 2018-10-09 S. O. Tickle , I. A. Eckley , P. Fearnhead , K. Haynes

In this paper we present an efficient active-set method for the solution of convex quadratic programming problems with general piecewise-linear terms in the objective, with applications to sparse approximations and risk-minimization. The…

Optimization and Control · Mathematics 2023-03-01 Spyridon Pougkakiotis , Jacek Gondzio , Dionysios S. Kalogerias

Computational methods are proposed for solving a convex quadratic program (QP). Active-set methods are defined for a particular primal and dual formulation of a QP with general equality constraints and simple lower bounds on the variables.…

Optimization and Control · Mathematics 2018-09-28 Anders Forsgren , Philip E. Gill , Elizabeth Wong

We present a novel computational framework to simulate the electromechanical response of self-sensing carbon nanotube (CNT)-based composites experiencing fracture. The computational framework combines electrical-deformation-fracture finite…

Computational Engineering, Finance, and Science · Computer Science 2023-02-22 L. Quinteros , E. García-Macías , E. Martínez-Pañeda

Motivated by the inadequacy of conducting atomistic simulations of crack propagation using static boundary conditions that do not reflect the movement of the crack tip, we extend Sinclair's flexible boundary condition algorithm [Philos.…

Computational Physics · Physics 2021-03-10 Maciej Buze , James R. Kermode

The purpose of this work is the development of space-time discretization schemes for phase-field optimal control problems. First, a time discretization of the forward problem is derived using a discontinuous Galerkin formulation. Here, a…

Optimization and Control · Mathematics 2022-03-24 Denis Khimin , Marc C. Steinbach , Thomas Wick

In this contribution we investigate the application of phase-field fracture models on non-linear multiscale computational homogenization schemes. In particular, we introduce different phase-fields on a two-scale problem and develop a…

Computational Engineering, Finance, and Science · Computer Science 2023-12-21 Felix Schmidt , Stefan Schuß , Christian Hesch

This paper addresses the modeling of fracture in quasi-brittle materials using a phase-field approach to the description of crack topology. Within the computational mechanics community, several studies have treated the issue of modeling…

Computational Engineering, Finance, and Science · Computer Science 2019-03-01 Jacinto Ulloa , Patricio Rodríguez , Cristóbal Samaniego , Esteban Samaniego