Weiliang Gao¹, Shixu Jia², Tingting Zhao^2,3,*, Zhiyong Wang²

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.3, pp. 3495-3511, 2024, DOI:10.32604/cmes.2023.046188

Abstract The mechanical properties of interfacial transition zones (ITZs) have traditionally been simplified by reducing the stiffness of cement in previous simulation methods. A novel approach based on the discrete element method (DEM) has been developed for modeling concrete. This new approach efficiently simulates the meso-structure of ITZs, accurately capturing their heterogeneous properties. Validation against established uniaxial compression experiments confirms the precision of this model. The proposed model can model the process of damage evolution containing cracks initiation, propagation and penetration. Under increasing loads, cracks within ITZs progressively accumulate, culminating in macroscopic fractures that traverse the mortar matrix, forming the complex,… More >

Lifan Chen^1,*, Ning Guo¹, Zhongxuan Yang¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.2, pp. 1-1, 2023, DOI:10.32604/icces.2023.09709

Abstract A multiscale approach [1] that couples the finite-element method (FEM) and the discrete-element method (DEM) is employed to model and analyse the earthquake fault rupture-soil-foundation interaction (FR-SFI) problem. In the approach, the soil constitutive responses are obtained from DEM solutions of representative volume elements (RVEs) embedded at the FEM integration points so as to effectively bypass the phenomenological hypotheses in conventional FEM simulations. The fault rupture surfaces and shear localization patterns under normal faults with or without foundation atop have been well captured by the multiscale approach and verified with available centrifuge experimental [2] and numerical results [3]. By examining… More >

Ruifeng Zhao¹, Zhijun Wu^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.25, No.1, pp. 1-2, 2023, DOI:10.32604/icces.2023.09814

Abstract The combined finite-discrete element method (FDEM) can effectively simulate the continuousdiscontinuous failure process of rocks, and is now widely adopted to investigate the issues related to rock mechanics and engineering. The conventional FDEM requires pre-defines constitutive models to calculate the element stress from element deformations [1]. However, the constitutive model used in conventional FDEM is obtained by empirical fitting of rock mechanics test data, and large amount of rock physical and mechanical information present in the test data, such as the nonlinear properties of rock presented in the initial compaction stage, are lost in the process of fitting test data… 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 >

Sen Zhang¹, Jie Jiang^2,3,*, Yuedong Wang⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.5, pp. 1159-1172, 2023, DOI:10.32604/fdmp.2022.024070

Abstract To improve the application of discrete element models (DEM) to the design of agricultural crushers, in this study a new highly accurate model is elaborated. The model takes into account the fiber structure, porous nature of the material and the leaf sheath coating structure. Dedicated experimental tests are conducted to determine the required “intrinsic” and basic contact parameters of the considered banana straw materials. A large number of bonding parameters are examined in relation to the particle aggregation model in order to characterize different actual banana straws. Using the particle surface energy contact model, the viscosity characteristics of the crushed… More > Graphic Abstract

Qizhi Chen¹, Chuli Xu¹, Baoping Zou^1,*, Zhanyou Luo², Changjie Xu³, Xu Long^4,*

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.2, pp. 1503-1520, 2023, DOI:10.32604/cmes.2022.022823

Abstract Load transformation from the yielding part of the soil to the adjacent part is known as the soil arching effect, which plays an important role in the design of various geotechnical infrastructures. Terzaghi’s trapdoor test was an important milestone in the development of theories on soil arching. The research on earth pressure of the trapdoor problem is presented in this paper using the three-dimensional (3D) discrete element method (DEM). Five 3D trapdoor models with different heights are established by 3D DEM software PFC 3D. The variation of earth pressure on the trapdoor with the downward movement of the trapdoor, the… More >

Tao Xue¹, Yazhou Wang², Masao Shimada², David Tae², Kumar Tamma^2,*, Xiaobing Zhang^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.134, No.3, pp. 1469-1487, 2023, DOI:10.32604/cmes.2022.021616

Abstract In this work, a consistent and physically accurate implementation of the general framework of unified second-order time accurate integrators via the well-known GSSSS framework in the Discrete Element Method is presented. The improved tangential displacement evaluation in the present implementation of the discrete element method has been derived and implemented to preserve the consistency of the correct time level evaluation during the time integration process in calculating the algorithmic tangential displacement. Several numerical examples have been used to validate the proposed tangential displacement evaluation; this is in contrast to past practices which only seem to attain the first-order time accuracy… More >

Hongri Zhu, Shunying Ji^*

CMES-Computer Modeling in Engineering & Sciences, Vol.132, No.1, pp. 5-21, 2022, DOI:10.32604/cmes.2022.019991

Abstract Moored structures are suitable for operations in ice-covered regions owing to their security and efficiency. This paper aims to present a new method for simulating the ice load and mooring force on the moored structure during ice-structure interaction with a spherical Discrete Element Method (DEM). In this method, the level ice and mooring lines consist of bonded sphere elements arranged in different patterns. The level ice model has been widely validated in simulation of the ice load of fixed structures. In the mooring line simulation, a string of spherical elements was jointed with the parallel bond model to simulate the… More >

Biyao Zhai, Lu Liu, Shunying Ji^*

CMES-Computer Modeling in Engineering & Sciences, Vol.130, No.1, pp. 1-22, 2022, DOI:10.32604/cmes.2022.018652

Abstract Freezing in ice rubble is a common phenomenon in cold regions, which can consolidate loose blocks and change their mechanical properties. To model the cohesive effect in frozen ice rubble, and to describe the fragmentation behavior with a large external forces exerted, a freeze-bond model based on the dilated polyhedral discrete element method (DEM) is proposed. Herein, imaginary bonding is initialized at the contact points to transmit forces and moments, and the initiation of the damage is detected using the hybrid fracture model. The model is validated through the qualitative agreement between the simulation results and the analytical solution of… More >

Shaomin Liang, Lu Liu, Shunying Ji^*

CMES-Computer Modeling in Engineering & Sciences, Vol.128, No.1, pp. 145-160, 2021, DOI:10.32604/cmes.2021.016403

Abstract Based on the discrete element method and hydrostatics theory, an improved Archimedes principle is proposed to study the rules pertaining to resistance changes during the penetration process of an intruder into the particulate materials. The results illustrate the fact that the lateral contribution to the resistance is very small, while the tangential force of the lateral resistance originates from friction effects. Conversely, the resistance of particulate materials on the intruder mainly occurs at the bottom part of the intruding object. Correspondingly, the factors that determine the resistance of the bottom part of the intruding object and the rules pertaining to… More >