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Article
Publication date: 1 August 1999

Jaroslav Mackerle

This paper gives a bibliographical review of the finite element methods (FEMs) applied to the analysis of ceramics and glass materials. The bibliography at the end of the paper…

2607

Abstract

This paper gives a bibliographical review of the finite element methods (FEMs) applied to the analysis of ceramics and glass materials. The bibliography at the end of the paper contains references to papers, conference proceedings and theses/dissertations on the subject that were published between 1977‐1998. The following topics are included: ceramics – material and mechanical properties in general, ceramic coatings and joining problems, ceramic composites, ferrites, piezoceramics, ceramic tools and machining, material processing simulations, fracture mechanics and damage, applications of ceramic/composites in engineering; glass – material and mechanical properties in general, glass fiber composites, material processing simulations, fracture mechanics and damage, and applications of glasses in engineering.

Details

Engineering Computations, vol. 16 no. 5
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 23 August 2011

Luis Kosteski, Ignacio Iturrioz, Ruben Galiano Batista and Adrián P. Cisilino

The purpose of this paper is to further develop the truss‐like discrete element method (DEM) in order to make it suitable to deal with damage and fracture problems.

Abstract

Purpose

The purpose of this paper is to further develop the truss‐like discrete element method (DEM) in order to make it suitable to deal with damage and fracture problems.

Design/methodology/approach

Finite and boundary elements are the best developed methods in the field of numerical fracture and damage mechanics. However, these methods are based on a continuum approach, and thus, the modelling of crack nucleation and propagation could be sometimes a cumbersome task. Besides, discrete methods possess the natural ability to introduce discontinuities in a very direct and intuitive way by simply breaking the link between their discrete components. Within this context, the present work extends the capabilities of a truss‐like DEM via the introduction of three novel features: a tri‐linear elasto‐plastic constitutive law; a methodology for crack discretization and the computation of stress intensity factors; and a methodology for the computation of the stress field components from the unixial discrete‐element results.

Findings

Obtained results show the suitability and the performance of the proposed methodologies to solve static and dynamic crack problems (including crack propagation) in brittle and elasto‐plastic materials. Computed results are in good agreement with experimental and numerical results reported in the bibliography.

Research limitations/implications

This paper demonstrates the versatility of the truss‐like DEM to deal with damage mechanics problems. The approach used in this work can be extended to the implementation of time‐dependent damage mechanisms. Besides, the capabilities of the discrete approach could be exploited by coupling the truss‐like DEM to finite and boundary element methods. Coupling strategies would allow using the DEM to model the regions of the problem where crack nucleation and propagation occurs, while finite or boundary elements are used to model the undamaged regions.

Originality/value

The scope of the truss‐like DEM has been extended. New procedures have been introduced to deal with elastoplastic‐crack problems and to improve the post processing of the stress results.

Article
Publication date: 17 August 2012

Jorge Palma Carrasco, José Maria Andrade Barbosa, Antonio Almeida Silva and Marcos Antonio da Silva Irmão

The purpose of this paper is to present a numerical simulation of the hydrogen atomic effect on the steels fracture toughness, as well as on crack propagation using fracture

Abstract

Purpose

The purpose of this paper is to present a numerical simulation of the hydrogen atomic effect on the steels fracture toughness, as well as on crack propagation using fracture mechanics and continuous damage mechanics models.

Design/methodology/approach

The simulation was performed in an idealized elastic specimen with an edge crack loaded in the tensile opening mode, in a plane strain state. In order to simulate the effect of hydrogen in the steel, the stress intensity factor ahead of the crack tip in the hydrogenated material was obtained. The damage model was applied to simulate the growth and crack propagation being considered only two damage components: a mechanical damage produced by a static load and a non‐mechanical damage produced by the hydrogen.

Findings

The simulation results showed that the changes in the stress field at the crack tip and the reduction in the time of growth and crack propagation due to hydrogen effect occur. These results showed a good correlation and consistency with macroscopic observations, providing a better understanding of the hydrogen embrittlement phenomenon in steels.

Originality/value

The paper attempts to link the concepts of the continuous damage and fracture mechanics to achieve a better approach in the representation of the physical phenomenon studied, in order to obtain a more accurate simulation of the processes involved.

Article
Publication date: 4 January 2021

Yongliang Wang

Optimized three-dimensional (3D) fracture networks are crucial for multistage hydrofracturing. To better understand the mechanisms controlling potential disasters as well as to…

Abstract

Purpose

Optimized three-dimensional (3D) fracture networks are crucial for multistage hydrofracturing. To better understand the mechanisms controlling potential disasters as well as to predict them in 3D multistage hydrofracturing, some governing factors, such as fluid injection-induced stratal movement, compression between multiple hydraulic fractures, fracturing fluid flow, fracturing-induced microseismic damaged and contact slip events, must be properly simulated via numerical models. This study aims to analyze the stratal movement and microseismic behaviours induced by multistage propagation of 3D multiple hydraulic fractures.

Design/methodology/approach

Adaptive finite element–discrete element method was used to overcome the limitations of conventional finite element methods in simulating 3D fracture propagation. This new approach uses a local remeshing and coarsening strategy to ensure the accuracy of solutions, reliability of fracture propagation path and computational efficiency. Engineering-scale numerical models were proposed that account for the hydro-mechanical coupling and fracturing fluid leak-off, to simulate multistage propagation of 3D multiple hydraulic fractures, by which the evolution of the displacement, porosity and fracture fields, as well as the fracturing-induced microseismic events were computed.

Findings

Stratal movement and compression between 3D multiple hydraulic fractures intensify with increasing proximity to the propagating fractures. When the perforation cluster spaces are very narrow, alternate fracturing can improve fracturing effects over those achieved via sequential or simultaneous fracturing. Furthermore, the number and magnitude of microseismic events are directly proportional to the stratal movement and compression induced by multistage propagation of fracturing fracture networks.

Originality/value

Microseismic events induced by multistage propagation of 3D multiple hydraulic fractures and perforation cluster spaces and fracturing scenarios that impact the deformation and compression among fractures in porous rock matrices are well predicted and analyzed.

Article
Publication date: 8 May 2018

Xudong Chen and Andrew Chan

This paper aims to investigate the responses of laminated glass under soft body impact, including elastic impact and fracture/fragmentation consideration.

Abstract

Purpose

This paper aims to investigate the responses of laminated glass under soft body impact, including elastic impact and fracture/fragmentation consideration.

Design/methodology/approach

The simulation uses the combined finite-discrete element method (FDEM) which combines finite element mesh into discrete elements, enabling the accurate prediction of contact force and deformation. Material rupture is modelled with a cohesive fracture criterion, evaluating the process from continua to discontinua.

Findings

Responses of laminated glass under soft impact (both elastic and fracture) agree well with known data. Crack initiation time in laminated glass increases with the increase of the outside glass thickness. With the increase of Eprojectile, failure mode is changing from flexural to shear, and damage tends to propagate longitudinally when the contact surface increases. Results show that the FDEM is capable of modelling soft impact behaviour of laminated glass successfully.

Research limitations/implications

The work is done in 2D, and it will not represent fully the 3D mechanisms.

Originality/value

Elastic and fracture behaviour of laminated glass under soft impact is simulated using the 2D FDEM. Limited work has been done on soft impact of laminated glass with FDEM, and special research endeavours are warranted. Benchmark examples and discussions are provided for future research.

Details

Engineering Computations, vol. 35 no. 3
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 1 November 2010

F.J.P. Reis, L. Malcher, F.M. Andrade Pires and J.M.A. César de Sá

The purpose of this paper is to perform a numerical assessment of two recently proposed extensions of the Gurson‐Tveegard‐Needleman ductile damage constitutive model under low…

Abstract

Purpose

The purpose of this paper is to perform a numerical assessment of two recently proposed extensions of the Gurson‐Tveegard‐Needleman ductile damage constitutive model under low stress triaxiality.

Design/methodology/approach

One of the most widely used ductile damage models is the so‐called Gurson‐Tveegard‐Needleman model, commonly known as GTN model. The GTN model has embedded into its damage formulation the effects of nucleation, growth and coalescence of micro‐voids. However, the GTN model does not include void distortion and inter‐void linking in the damage evolution. To overcome this limitation, some authors have proposed the introduction of different shear mechanisms based on micromechanical grounds or phenomenological assumptions. Two of these constitutive formulations are reviewed in this contribution, numerically implemented within a quasi‐static finite element framework and their results critically appraised.

Findings

Through the analysis of the evolution of internal variables, such as damage and effective plastic strain, obtained by performing a set of numerical tests using a Butterfly specimen, it is possible to conclude that the extended GTN models are in close agreement with experimental evidence.

Research limitations/implications

Even though the results obtained with the modified GTN models have shown improvements, it can also be observed that both shear mechanisms have inherent limitations in the prediction of the location of fracture onset for some specific stress states.

Originality/value

From the results reported, it is possible to identify some shortcomings in the recently proposed extensions of the GTN model and point out the direction of further improvements.

Details

International Journal of Structural Integrity, vol. 1 no. 4
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 1 April 2005

Jaroslav Mackerle

Ceramic materials and glasses have become important in modern industry as well as in the consumer environment. Heat resistant ceramics are used in the metal forming processes or…

5130

Abstract

Purpose

Ceramic materials and glasses have become important in modern industry as well as in the consumer environment. Heat resistant ceramics are used in the metal forming processes or as welding and brazing fixtures, etc. Ceramic materials are frequently used in industries where a wear and chemical resistance are required criteria (seals, liners, grinding wheels, machining tools, etc.). Electrical, magnetic and optical properties of ceramic materials are important in electrical and electronic industries where these materials are used as sensors and actuators, integrated circuits, piezoelectric transducers, ultrasonic devices, microwave devices, magnetic tapes, and in other applications. A significant amount of literature is available on the finite element modelling (FEM) of ceramics and glass. This paper gives a listing of these published papers and is a continuation of the author's bibliography entitled “Finite element modelling of ceramics and glass” and published in Engineering Computations, Vol. 16, 1999, pp. 510‐71 for the period 1977‐1998.

Design/methodology/approach

The form of the paper is a bibliography. Listed references have been retrieved from the author's database, MAKEBASE. Also Compendex has been checked. The period is 1998‐2004.

Findings

Provides a listing of 1,432 references. The following topics are included: ceramics – material and mechanical properties in general, ceramic coatings and joining problems, ceramic composites, piezoceramics, ceramic tools and machining, material processing simulations, fracture mechanics and damage, applications of ceramic/composites in engineering; glass – material and mechanical properties in general, glass fiber composites, material processing simulations, fracture mechanics and damage, and applications of glasses in engineering.

Originality/value

This paper makes it easy for professionals working with the numerical methods with applications to ceramics and glasses to be up‐to‐date in an effective way.

Details

Engineering Computations, vol. 22 no. 3
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 1 November 2022

Yongliang Wang and Xin Zhang

Hydrofracturing technology has been widely used in tight oil and gas reservoir exploitation, and the fracture network formed by fracturing is crucial to determining the resources…

Abstract

Purpose

Hydrofracturing technology has been widely used in tight oil and gas reservoir exploitation, and the fracture network formed by fracturing is crucial to determining the resources recovery rate. Due to the complexity of fracture network induced by the random morphology and type of fluid-driven fractures, controlling and optimising its mechanisms is challenging. This paper aims to study the types of multiscale mode I/II fractures, the fluid-driven propagation of multiscale tensile and shear fractures need to be studied.

Design/methodology/approach

A dual bilinear cohesive zone model (CZM) based on energy evolution was introduced to detect the initiation and propagation of fluid-driven tensile and shear fractures. The model overcomes the limitations of classical linear fracture mechanics, such as the stress singularity at the fracture tip, and considers the important role of fracture surface behaviour in the shear activation. The bilinear cohesive criterion based on the energy evolution criterion can reflect the formation mechanism of complex fracture networks objectively and accurately. Considering the hydro-mechanical (HM) coupling and leak-off effects, the combined finite element-discrete element-finite volume approach was introduced and implemented successfully, and the results showed that the models considering HM coupling and leak-off effects could form a more complex fracture network. The multiscale (laboratory- and engineering-scale) Mode I/II fractures can be simulated in hydrofracturing process.

Findings

Based on the proposed method, the accuracy and applicability of the algorithm were verified by comparing the analytical solution of KGD and PKN models. The effects of different in situ stresses and flow rates on the dynamic propagation of hydraulic fractures at laboratory and engineering scales were investigated. when the ratio of in situ stress is small, the fracture propagation direction is not affected, and the fracture morphology is a cross-type fracture. When the ratio of in situ stress is relatively large, the propagation direction of the fracture is affected by the maximum in situ stress, and it is more inclined to propagate along the direction of the maximum in situ stress, forming double wing-type fractures. Hydrofracturing tensile and shear fractures were identified, and the distribution and number of each type were obtained. There are fewer hydraulic shear fractures than tensile fractures, and shear fractures appear in the initial stage of fracture propagation and then propagate and distribute around the perforation.

Originality/value

The proposed dual bilinear CZM is effective for simulating the types of Mode I/II fractures and seizing the fluid-driven propagation of multiscale tensile and shear fractures. Practical fracturing process involves the multi-type and multiscale fluid-driven fracture propagation. This study introduces general fluid-driven fracture propagation, which can be extended to the fracture propagation analysis of potential fluid fracturing, such as other liquids or supercritical gases.

Content available
Article
Publication date: 1 June 2002

237

Abstract

Details

Aircraft Engineering and Aerospace Technology, vol. 74 no. 3
Type: Research Article
ISSN: 0002-2667

Keywords

Article
Publication date: 26 October 2021

Yongliang Wang, Nana Liu, Xin Zhang, Xuguang Liu and Juan Wang

Simultaneous hydrofracturing of multiple perforation clusters in vertical wells has been applied in the stimulation of hydrocarbon resources reservoirs. This technology is…

Abstract

Purpose

Simultaneous hydrofracturing of multiple perforation clusters in vertical wells has been applied in the stimulation of hydrocarbon resources reservoirs. This technology is significantly impeded due to the challenges in its application to the multilayered reservoirs that comprise multiple interlayers. One of the challenges is the accurate understanding and characterization of propagation and deflection of the multiple hydraulic fractures between reservoirs and embedded interlayers.

Design/methodology/approach

Numerical models of the tight multilayered reservoirs containing multiple interlayers were established to study hydrofracturing of multiple perforation clusters and its influencing factors on unstable propagation and deflection of hydraulic fractures. Brittle and plastic multilayered reservoirs fully considering the influences of different in situ stress ratio and physical attributes for reservoir and interlayer strata on propagations of hydraulic fractures were investigated. The combined finite element–discrete element method and mesh refinement strategy were adopted to guarantee the accuracy of stress solutions and reliability of fracture path in computation.

Findings

Results show that the shear stress fields between adjacent multiple hydraulic fractures are superposed to cause fractures deflection. Stress shadows induce the shielding effects of hydraulic fractures and inhibit fractures growth to emerge unstable propagation behaviors, and a main single fracture and several minor fractures develop. As the in situ stress ratio increases, hydraulic fractures more easily deflect toward the direction of maximum in situ stress, and stress shadow and mutual interaction effects between them are intensified. Compared to brittle reservoir, plastic-enhanced reservoir may limit fracture growth and cannot form long fracture length; nevertheless, plastic properties of reservoir are prone to induce more microseismic events with larger magnitude.

Originality/value

The obtained fracturing behaviors and mechanisms based on engineering-scale multilayered reservoir may provide effective schemes for controlling and estimating the unstable propagation of multiple hydraulic fractures.

1 – 10 of over 3000