Chenxi Xiu^1,2,*, Xihua Chu²

CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.3, pp. 2305-2338, 2024, DOI:10.32604/cmes.2023.030194

Abstract This paper presents a micromechanics-based Cosserat continuum model for microstructured granular materials. By utilizing this model, the macroscopic constitutive parameters of granular materials with different microstructures are expressed as sums of microstructural information. The microstructures under consideration can be classified into three categories: a medium-dense microstructure, a dense microstructure consisting of one-sized particles, and a dense microstructure consisting of two-sized particles. Subsequently, the Cosserat elastoplastic model, along with its finite element formulation, is derived using the extended Drucker-Prager yield criteria. To investigate failure behaviors, numerical simulations of granular materials with different microstructures are conducted using the ABAQUS User Element (UEL)… More >

Peter Watson¹, Sebastien Vincent Bonnieu², Marcello Lappa^1,*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.1, pp. 1-29, 2024, DOI:10.32604/fdmp.2023.029280

Abstract We present a short retrospective review of the existing literature about the dynamics of (dry) granular matter under the effect of vibrations. The main objective is the development of an integrated resource where vital information about past findings and recent discoveries is provided in a single treatment. Special attention is paid to those works where successful synthetic routes to as-yet unknown phenomena were identified. Such landmark results are analyzed, while smoothly blending them with a history of the field and introducing possible categorizations of the prevalent dynamics. Although no classification is perfect, and it is hard to distillate general properties… More >

Deze Yang, Xihua Chu^*

CMES-Computer Modeling in Engineering & Sciences, Vol.136, No.1, pp. 63-85, 2023, DOI:10.32604/cmes.2023.025062

Abstract The particle size ratio (PSR) is an important parameter for binary granular materials, which may affect the microstructure and macro behaviors of granular materials. However, the effect of particle ratio on granular assemblies with different arrangements is still unclear. To explore and further clarify the effect of PSR in different packing structures, three types of numerical samples with regular, layered, and random packing are designed. Numerical results show that PSR has significant effects on binary granular samples with regular packing. The larger the PSR, the stronger the strength, the larger the modulus, and the smaller the angle between the shear… More >

Shunying Ji^1,*, Michael Zhuravkov², Zongyan Zhou³, Yuntian Feng⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.132, No.1, pp. 1-3, 2022, DOI:10.32604/cmes.2022.023238

Abstract This article has no abstract. More >

Jiao Wang^1,*, Xihua Chu^2,*, Jinbao Wang³

CMES-Computer Modeling in Engineering & Sciences, Vol.130, No.2, pp. 653-670, 2022, DOI:10.32604/cmes.2022.018207

Abstract Common structures in engineering such as slopes, roadbeds, ballasts, etc., are closely related to granular materials. They are usually subjected to long-term cyclic loads. This study mainly focused on the mechanical behaviors of randomly arranged granular materials before they reach a stable state under different cyclic loads. The variation of the maximum axial strain and the influence of CSR (cyclic stress ratio) were analyzed. The energy consumed in each cycle under constant confining stress loading condition is significantly greater than that of the fixed wall loading condition. The internal deformation evolution of granular materials is studied in detail. The deformation… More >

Tongming Qu¹, Shaocheng Di², Y. T. Feng^1,3,*, Min Wang⁴, Tingting Zhao³, Mengqi Wang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.128, No.1, pp. 129-144, 2021, DOI:10.32604/cmes.2021.016172

Abstract This study presents an AI-based constitutive modelling framework wherein the prediction model directly learns from triaxial testing data by combining discrete element modelling (DEM) and deep learning. A constitutive learning strategy is proposed based on the generally accepted frame-indifference assumption in constructing material constitutive models. The low-dimensional principal stress-strain sequence pairs, measured from discrete element modelling of triaxial testing, are used to train recurrent neural networks, and then the predicted principal stress sequence is augmented to other high-dimensional or general stress tensor via coordinate transformation. Through detailed hyperparameter investigations, it is found that long short-term memory (LSTM) and gated recurrent… More >

Wei Cai^*, Hua Chen

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 80-80, 2019, DOI:10.32604/icces.2019.05672

Abstract Recent decades have witnessed a fast growing research on the theory of wave propagation in granular materials because of its important applications of frequency dependent attenuation. Fractional calculus has been recognized as an efficient tool to model such kind of phenomena. This study firstly presented a survey of the frequency-dependent attenuated fractional wave models. To have a better understanding of the wave propagation in layered materials, the variable-order fractional wave equation is subsequently proposed on the basis of the corresponding viscoelastic constitutive equation. Numerical simulations compared with traditional models are presented by the implicit finite difference method to the efficiency… More >

Emil Budescu¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.11, No.1, pp. 17-18, 2009, DOI:10.3970/icces.2009.011.017

Abstract For the visco-plastic materials of type Bingham fluid, like granular materials, the process of flow begins when the force F^ˉ, which variation is presented in figure 1, reaches the minimum value of shearing limit. More >

Fujun Yang^*, Lingpeng Zhang, Yinhang Ma, Hanyang Jiang, Xiaoyun He

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.1, pp. 3-3, 2019, DOI:10.32604/icces.2019.05395

Abstract Granular materials such as soil and sand are ubiquitous. Particle size and shape of granular materials has great influence on their mechanical behavior, such as compressibility, yield strength and permeability. In this research, uniaxial compression experiment is carried out on sands, to study deformation evolution and force transmission of granular materials, by using electronic speckle pattern interferometry (ESPI). The testing sample is the dense mixture of different size sand particles. Three dimensional (3-D) displacement information is obtained by the 3-CCD color camera and phase-shifting method. Three different color laser lights (in Red, Green and Blue) and only one PZT transducer… More >

Yang Yang¹, Anil Misra²

CMES-Computer Modeling in Engineering & Sciences, Vol.64, No.1, pp. 1-36, 2010, DOI:10.3970/cmes.2010.064.001

Abstract Gradient theories have found wide applications in modeling of strain softening phenomena. This paper presents a higher order stress-strain theory to describe the damage behavior of strain softening materials. In contrast to most conventional gradient approaches for damage modeling, the present higher order theory considers strain gradients and their conjugate higher-order stress such that stable numerical solutions may be achieved. We have described the derivation of the required constitutive relationships, the governing equations and its weak form for this higher-order theory. The constitutive coefficients were obtained from a granular media approach such that the internal length scale parameter reflects the… More >