A comparative review of peridynamics and phase-field models for engineering fracture mechanics

Computational modeling of the initiation and propagation of complex fracture is central to the discipline of engineering fracture mechanics. This review focuses on two promising approaches: phase-field (PF) and peridynamic (PD) models applied to this class of problems. The basic concepts consisting of constitutive models, failure criteria, discretization schemes, and numerical analysis are briefly summarized for both models. Validation against experimental data is essential for all computational methods to demonstrate predictive accuracy. To that end, the Sandia Fracture Challenge and similar experimental data sets where both models could be benchmarked against are showcased. Emphasis is made to converge on common metrics for the evaluation of these two fracture modeling approaches. Both PD and PF models are assessed in terms of their computational effort and predictive capabilities, with their relative advantages and challenges are summarized. © 2022, The Author(s)

A comparative review of peridynamics and phase-field models for engineering fracture mechanics

Computational modeling of the initiation and propagation of complex fracture is central to the discipline of engineering fracture mechanics. This review focuses on two promising approaches: phase-field (PF) and peridynamic (PD) models applied to this class of problems. The basic concepts consisting of constitutive models, failure criteria, discretization schemes, and numerical analysis are briefly summarized for both models. Validation against experimental data is essential for all computational methods to demonstrate predictive accuracy. To that end, the Sandia Fracture Challenge and similar experimental data sets where both models could be benchmarked against are showcased. Emphasis is made to converge on common metrics for the evaluation of these two fracture modeling approaches. Both PD and PF models are assessed in terms of their computational effort and predictive capabilities, with their relative advantages and challenges are summarized

State Of the Art Report in the fields of numerical analysis and scientific computing. Final version as of 16/02/2020 deliverable D4.1 of the HORIZON 2020 project EURAD.: European Joint Programme on Radioactive Waste Management

Document information Project Acronym EURAD Project Title European Joint Programme on Radioactive Waste Management Project Type European Joint Programme (EJP) EC grant agreement No. 847593 Project starting / end date 1 st June 2019-30 May 2024 Work Package No. 4 Work Package Title Development and Improvement Of NUmerical methods and Tools for modelling coupled processes Work Package Acronym DONUT Deliverable No. 4.

Efficient Seismic Depth Imaging and Full-Waveform Inversion via Generalized Multiscale Finite Element

Reverse-time migration (RTM) and full-waveform inversion (FWI) are widely used because they are able to recover complex geological structures. However, these wave-equation based imaging techniques also have a drawback, as they require significant computational cost. In both methods, wave modeling accounts for the largest part of the computing cost for calculating forward-and backward-propagated wavefields before constructing an imaging condition or a model update term. For this reason, I applied a model reduction technique, the generalized multiscale finite el-ment method (GMsFEM), which solves local spectral problems on a fine grid for fast simulation of wave propagation on a coarser grid. This approach can enhance the speed of computation without sacrificing accuracy by utilizing coarser grids for lower frequency waves. In the proposed method, one can control the size of the coarse grid and level of heterogeneity of the wave solutions to tune the trade-off between speedup and accuracy. As I increase the expected level of complexity of the wave solutions, the GMsFEM wave modeling can capture more detailed features of waves by applying a finer coarse grid and a larger number of basis functions. After computing the forward-and backward-wavefield on the coarse grid, the coarse-scale solutions are projected onto the original fine grid. Therefore, although wave solutions are computed on a coarse grid, it still provides the images for RTM and FWI without reducing the image resolution by projecting coarse wave solutions to the fine grid. In the multiscale finite element approach, one can apply flexible wave modeling parameters (i.e., grid size, number of basis functions) according to the target frequency components, which makes the method an attractive tool for the practical applications of the RTM and FWI. I demonstrated the multiscale FWI using the BP and Marmousi-2 synthetic model. In addition, I show FWI examples of the field data obtained in the Gulf of Mexico region. In the field data examples, I demonstrate that applying the proposed multiscale RTM and FWI with a relatively small number of basis functions can quickly construct a macro velocity model using low frequency. I also propose a strategy to maximize the efficiency of the multiscale FWI by utilizing frequency-adaptive multiscale basis functions based on the target frequency group

Computational Modelling of Concrete and Concrete Structures

Computational Modelling of Concrete and Concrete Structures contains the contributions to the EURO-C 2022 conference (Vienna, Austria, 23-26 May 2022). The papers review and discuss research advancements and assess the applicability and robustness of methods and models for the analysis and design of concrete, fibre-reinforced and prestressed concrete structures, as well as masonry structures. Recent developments include methods of machine learning, novel discretisation methods, probabilistic models, and consideration of a growing number of micro-structural aspects in multi-scale and multi-physics settings. In addition, trends towards the material scale with new fibres and 3D printable concretes, and life-cycle oriented models for ageing and durability of existing and new concrete infrastructure are clearly visible. Overall computational robustness of numerical predictions and mathematical rigour have further increased, accompanied by careful model validation based on respective experimental programmes. The book will serve as an important reference for both academics and professionals, stimulating new research directions in the field of computational modelling of concrete and its application to the analysis of concrete structures. EURO-C 2022 is the eighth edition of the EURO-C conference series after Innsbruck 1994, Bad Gastein 1998, St. Johann im Pongau 2003, Mayrhofen 2006, Schladming 2010, St. Anton am Arlberg 2014, and Bad Hofgastein 2018. The overarching focus of the conferences is on computational methods and numerical models for the analysis of concrete and concrete structures