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Article

De-Cheng Feng, Cheng-Dong Yang and Xiao-Dan Ren

This paper aims to present a multi-scale stochastic damage model (SDM) for concrete and apply it to the stochastic response analysis of reinforced concrete shear wall structures.

Abstract

Purpose

This paper aims to present a multi-scale stochastic damage model (SDM) for concrete and apply it to the stochastic response analysis of reinforced concrete shear wall structures.

Design/methodology/approach

The proposed SDM is constructed at two scales, i.e. the macro-scale and the micro-scale. The general framework of the SDM is established on the basis of the continuum damage mechanics (CDM) at the macro-scale, whereas the detailed damage evolution is determined through a parallel fiber buddle model at the micro-scale. The parallel buddle model is made up of micro-elements with stochastic fracture strains, and a one-dimensional random field is assumed for the fracture strain distribution. To represent the random field, a random functional method is adopted to quantify the stochastic damage evolution process with only two variables; thus, the numerical efficiency is greatly enhanced. Meanwhile, the probability density evolution method (PDEM) is introduced for the structural stochastic response analysis.

Findings

By combing the SDM and PDEM, the probabilistic analysis of a shear wall structure is performed. The mean value, standard deviation and the probability density function of the shear wall responses, e.g., shear capacity, accumulated energy consumption and damage evolution, are obtained.

Originality/value

It is noted that the proposed method can reflect the influences of randomness from material level to structural level, and is efficient for stochastic response determination of shear wall structures.

Details

Engineering Computations, vol. 35 no. 6
Type: Research Article
ISSN: 0264-4401

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Article

Zheyuan Zheng and Zhaoxia Li

This paper aims to introduce a multiscale computational method for structural failure analysis with inheriting simulation of moving trans-scale boundary (MTB). This method…

Abstract

Purpose

This paper aims to introduce a multiscale computational method for structural failure analysis with inheriting simulation of moving trans-scale boundary (MTB). This method is motivated from the error in domain bridging caused by cross-scale damage evolution, which is common in structural failure induced by damage accumulation.

Design/methodology/approach

Within the method, vulnerable regions with high stress level are described by continuum damage mechanics, while elastic structural theory is sufficient for the rest, dividing the structural model into two scale domains. The two domains are bridged to generate mixed dimensional finite element equation of the whole system. Inheriting simulation is developed to make the computation of MTB sustainable.

Findings

Numerical tests of a notched three-point bending beam and a steel frame show that this MTB method can improve efficiency and ensure accuracy while capturing the effect of material damage on deterioration of components and structure.

Originality/value

The proposed MTB method with inheriting simulation is an extension of multiscale simulation to structural failure analysis. Most importantly, it can deal with cross-scale damage evolution and improve computation efficiency significantly.

Details

Engineering Computations, vol. 34 no. 5
Type: Research Article
ISSN: 0264-4401

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Article

J. Faleiro, S. Oller and A.H. Barbat

The purpose of this paper is to develop an improved analytical model for predicting the damage response of multi‐storey reinforced concrete frames modelled as an elastic…

Abstract

Purpose

The purpose of this paper is to develop an improved analytical model for predicting the damage response of multi‐storey reinforced concrete frames modelled as an elastic beam‐column with two inelastic hinges at its ends.

Design/methodology/approach

The damage is evaluated in the hinges, using the concentrated damage concepts and a new member damage evaluation method for frame members, which leads to a meaningful global damage index of the structure. A numerical procedure for predicting the damage indices of the structures using matrix structural analysis, plastic theory and continuum damage model is also developed. The method is adequate for the prediction of the failure mechanisms.

Findings

Using the proposed framework numerical examples are finally included. From the obtained results, the advantages and limitation of the proposed model are observed.

Originality/value

The numeric model presented is useful to solve multi‐storey reinforced concrete frames using an inexpensive procedure that combines structural finite elements (beams) of low execution cost, with the moment‐curvature constitutive models deriving from classic stress‐strain ones. The proposed techniques give an inexpensive and reliability procedure to model the frame structures.

Details

Engineering Computations, vol. 27 no. 1
Type: Research Article
ISSN: 0264-4401

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Article

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…

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

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Article

D. Brancherie and A. Ibrahimbegovic

The purpose of this paper is to present a finite element model capable of describing both the diffuse damage mechanism which develops first during the loading of massive…

Abstract

Purpose

The purpose of this paper is to present a finite element model capable of describing both the diffuse damage mechanism which develops first during the loading of massive brittle structures and the failure process, essentially due to the propagation of a macro‐crack responsible for the softening behaviour of the structure. The theoretical developments for such a model are presented, considering an isotropic damage model for the continuum and a Coulomb‐type criterion for the localized part.

Design/methodology/approach

This is achieved by activating subsequently diffuse and localized damage mechanisms. Localized phenomena are taken into account by means of the introduction of a displacement discontinuity at the element level.

Findings

It was found that, with such an approach, the final crack direction is predicted quite well, in fact much better than the prediction made by the fracture mechanics type of models considering combination of only elastic response and softening.

Originality/value

The presented model has the potential to describe complex damage phenomena in a cyclic and/or non‐proportional loading program, such as crack closing and re‐opening, cohesive resistance deterioration due to tangential sliding, by using only a few parameters compared to the traditional models for cyclic loading.

Details

Engineering Computations, vol. 26 no. 1/2
Type: Research Article
ISSN: 0264-4401

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Article

Jiang Hu

The multi-scale numerical simulation method, able to represent the complexity of the random structures and capture phase degradation, is an effective way to investigate…

Abstract

Purpose

The multi-scale numerical simulation method, able to represent the complexity of the random structures and capture phase degradation, is an effective way to investigate the long-term behavior of concrete in service and bridges the gap between research on the material and on the structural level. However, the combined chemical-physical deterioration mechanisms of concrete remain a challenging task. The purpose of this paper is to investigate the degradation mechanism of concrete at the waterline in cold regions induced by combined calcium leaching and frost damage.

Design/methodology/approach

With the help of the NIST’s three-dimensional (3D) hydration model and the random aggregate model, realistic 3D representative volume elements (RVEs) of concrete at the micro-, the meso-, and the macro-scales can be reconstructed. The boundary problem method is introduced to compute the homogenized mechanical properties for both sound and damaged RVEs. According to the damage characteristics, the staggering method including a random dissolution model and a thermo-mechanical coupling model is developed to simulate the synergy deterioration effects of interacted calcium leaching and frost attacks. The coupled damage procedure for the frost damage process is based on the hydraulic pressure theory and the ice lens growth theory considering the relationship between the frozen temperature and the radius of the capillary pore. Finally, regarding calcium leaching as the leading role in actual engineering, the numerical methodology for combined leaching and frost damage on concrete property is proposed using a successive multi-scale method.

Findings

On the basis of available experimental data, this methodology is employed to explore the deterioration process. The results agree with the experimental ones to some extent, chemical leaching leads to the nucleation of some micro-cracks (i.e. damage), and consequently, to the decrease of the frost resistance.

Originality/value

It is demonstrated that the multi-scale numerical methodology can capture potential aging and deterioration evolution processes, and can give an insight into the macroscopic property degradation of concrete under long-term aggressive conditions.

Details

Multidiscipline Modeling in Materials and Structures, vol. 12 no. 4
Type: Research Article
ISSN: 1573-6105

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Article

E.A. De Souza Neto, Djordje Perić and D.R.J. Owen

This work addresses the computational aspects of a model forelastoplastic damage at finite strains. The model is a modification of apreviously established model for large…

Abstract

This work addresses the computational aspects of a model for elastoplastic damage at finite strains. The model is a modification of a previously established model for large strain elastoplasticity described by Perić et al. which is here extended to include isotropic damage and kinematic hardening. Within the computational scheme, the constitutive equations are numerically integrated by an algorithm based on operator split methodology (elastic predictor—plastic corrector). The Newton—Raphson method is used to solve the discretized evolution equations in the plastic corrector stage. A numerical assessment of accuracy and stability of the integration algorithm is carried out based on iso‐error maps. To improve the stability of the local N—R scheme, the standard elastic predictor is replaced by improvedinitial estimates ensuring convergence for large increments. Several possibilities are explored and their effect on the stability of the N—R scheme is investigated. The finite element method is used in the approximation of the incremental equilibrium problem and the resulting equations are solved by the standard Newton—Raphson procedure. Two numerical examples are presented. The results are compared with those obtained by the original elastoplastic model.

Details

Engineering Computations, vol. 11 no. 3
Type: Research Article
ISSN: 0264-4401

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Article

Annan Jiang, Shuai Zheng and Shanyong Wang

This paper aims at the problem of surrounding rock excavation damage zone of tunneling in the rich water region, this paper aims to propose a new seepage-stress-damage

Abstract

Purpose

This paper aims at the problem of surrounding rock excavation damage zone of tunneling in the rich water region, this paper aims to propose a new seepage-stress-damage coupling model and studied the numerical algorithm. This reflects the characteristics of rock damage evolution, accompanied by plastic flow deformation and multi-field interaction.

Design/methodology/approach

First of all, rock elastoplastic damage constitutive model based on the Drucker–Prager criterion is established, the fully implicit return mapping algorithm is adopted to realize the numerical solution. Second, based on the relation between damage variation and permeability coefficient, the rock stress-seepage-damage model and multi-field coupling solving iterative method are presented. Finally, using the C++ language compiled the corresponding programs and simulated tunnel engineering in the rich water region.

Findings

Results show that difference evolution-based back analysis inversed damage parameters well, at the same time the established coupling model and calculating program have more advantages than general conventional methods. Multiple field coupling effects should be more considered for the design of tunnel support.

Originality/value

The proposed method provides an effective numerical simulation method for the construction of the tunnel and other geotechnical engineering involved underground water problems.

Details

Engineering Computations, vol. 37 no. 8
Type: Research Article
ISSN: 0264-4401

Keywords

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Article

Xinmei Wang, Yao Wang and Xinzhong Wang

Specimen thickness has great influences on the creep behavior of single crystal Ni-based superalloys when it is less than 3.0 mm, which is known as thickness debit effect…

Abstract

Purpose

Specimen thickness has great influences on the creep behavior of single crystal Ni-based superalloys when it is less than 3.0 mm, which is known as thickness debit effect. Experiments have detected that oxidation can influence the microstructure of the Ni-based superalloys. Here, a model is proposed to bring in both the oxidation effect and void caused damage to account for the thickness debit effect. The paper aims to discuss these issues.

Design/methodology/approach

The model uses the simple Norton type creep relation to describe the creep rate evolution. The damage evolution caused by void is taken to be stress controlled. The load baring area changes are calculated with the consideration of oxidation and void evolutions.

Findings

Simulations on specimens with different thickness from 3.0 to 0.3 mm are carried out. The results show that the present model can reproduce the decrease of the creep strength with the decreases of the specimen thickness. The damage plays a major role in the creep behavior of the thick specimen. Both the damage and the oxidation are important for the thin specimen which should be paid attention to during the calculation of the creep response of the thin-wall turbine blade.

Originality/value

A model is proposed to account for the thickness debit effect on the creep behavior of Ni-based superalloys. Both oxidation influence and void caused damage are introduced. The simulation results show the capability of the model to reproduce the thickness debit effect.

Details

Multidiscipline Modeling in Materials and Structures, vol. 13 no. 3
Type: Research Article
ISSN: 1573-6105

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Article

Xue Xinhua, Zhang Wohua and Xingguo Yang

The paper aims to clarify the relationship between the micro-structures of porous media and the coefficient of permeability. Most materials involve different types of…

Abstract

Purpose

The paper aims to clarify the relationship between the micro-structures of porous media and the coefficient of permeability. Most materials involve different types of defects like caves, pores and cracks, which are important characters of porous media and have a great influence on the physical properties of materials. To study the seepage mechanical characteristics of damaged porous media, the constitutive model of porous media dealing with coupled modeling of pores damage and its impact on permeability property of a deforming media was studied in this paper.

Design/methodology/approach

The paper opted for an exploratory study using the approach of continuum damage mechanics (CDM).

Findings

The paper provides some new insights on the fluid dynamics of porous media. The dynamic evolution model of permeability coefficient established in this paper can be used to model the fluid flow problems in damaged porous media. Moreover, the modified Darcy's law developed in this paper is considered to be an extension of the Darcy's law for fluid flow and seepage in a porous medium.

Research limitations/implications

Owing to the limitations of time, conditions, funds, etc., the research results should be subject to multifaceted experiments before their innovative significance can be fully verified.

Practical implications

The paper includes implications for the development of fluid dynamics of porous media.

Originality/value

This paper fulfils an identified need to study the relationship between the micro-structures of porous media and the coefficient of permeability.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 24 no. 2
Type: Research Article
ISSN: 0961-5539

Keywords

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