Zuoming Yin^1,*, Xuguang Wang², Desheng Wang¹, Zhiheng Dang¹, Jianfeng Shao³

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.2, pp. 257-269, 2022, DOI:10.32604/fdmp.2022.017915

Abstract The present study considers the so-called air deck blasting, one of the most commonly used techniques for the improvement of blasting efficiency in mining applications. In particular, it aims to improve the operating conditions of large-scale equipment, increase the efficiency of the slope enlarging process, and reduce the mining cost. These objectives are implemented through a two-fold approach where, first, a program for slope enlarging based on the middle air-deck charge blasting-loosening technology is proposed, and second, the physical mechanism responsible for the stress wave attenuation in the rock is analyzed in the framework of a Holmquist–Johnson–Cook constitutive model. Field… More >

Alexander Humer and Hans Irschik^*

CMES-Computer Modeling in Engineering & Sciences, Vol.129, No.3, pp. 1395-1417, 2021, DOI:10.32604/cmes.2021.017944

Abstract This paper addresses the application of the continuum mechanics-based multiplicative decomposition for thermohyperelastic materials by Lu and Pister to Reissner’s structural mechanics-based, geometrically exact theory for finite strain plane deformations of beams, which represents a geometrically consistent non-linear extension of the linear shear-deformable Timoshenko beam theory. First, the Lu-Pister multiplicative decomposition of the displacement gradient tensor is reviewed in a three-dimensional setting, and the importance of its main consequence is emphasized, i.e., the fact that isothermal experiments conducted over a range of constant reference temperatures are sufficient to identify constitutive material parameters in the stress-strain relations. We address various isothermal… 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 >

Lei Li, Guolai Yang^*, Jiahao Li

CMES-Computer Modeling in Engineering & Sciences, Vol.124, No.3, pp. 865-884, 2020, DOI:10.32604/cmes.2020.010720

Abstract This paper proposes a probabilistic life calculation method of NdFeB based on brittle fatigue damage model. Firstly, Zhu-Wang-Tang (ZWT) constitutive model considering strain rate is established, and based on this, a numerical co-simulation model for NdFeB life calculation is constructed. The life distribution diagram of NdFeB under different stress levels is obtained after simulation. Secondly, a new model of brittle fatigue damage based on brittle damage mechanism is proposed. Then the parameters in the model are identified according to the life distribution diagram of NdFeB and the parameter distribution of the damage evolution model when applied to NdFeB is obtained.… More >

Ying Song^1,2, Jiale Yan^1,2, Shaofan Li^2,*, Zhuang Kang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.2, pp. 465-492, 2019, DOI:10.32604/cmes.2019.07190

Abstract In the present work, a state-based peridynamics with adaptive particle refinement is proposed to simulate water ice crater formation due to impact loads. A modified Drucker-Prager constitutive model was adopted to model ice and was implemented in the state-based peridynamic equations to analyze the elastic-plastic deformation of ice. In simulations, we use the fracture toughness failure criterion in peridynamics to simulate the quasi-brittle failure of ice. An adaptive particle refinement method in peridynamics was proposed to improve computational efficiency. The results obtained using the peridynamic model were compared with the experiments in previous literatures. It was found that the peridynamic… More >

Zhi Zhang¹, Jianhua Tong^1,*

Molecular & Cellular Biomechanics, Vol.16, Suppl.1, pp. 43-43, 2019, DOI:10.32604/mcb.2019.05721

Abstract Diabetes is a major risk factor to cause macrovascular diseases and plays a pivotal role in aortic wall remodeling. However, the effects of diabetes on elastic properties of aortas remain largely unknown. Thirty adult rabbits (1.6-2.2 kg) were collected and the type I diabetic rabbit model was induced by injection of alloxan. A total of 15 control and 15 diabetic rabbit (abdominal) aortas were harvested. Uniaxial and biaxial tensile tests were performed to measure ultimate tensile strength and to characterize biaxial mechanical behaviors of the aortas. A material model was fitted to the biaxial experimental data to obtain constitutive parameters.… More >

Smitha Gopinath¹, J. Rajasankar^1,2, Nagesh R. Iyer¹, T. S. Krishnamoorthy¹, B.H.Bharatkumar¹, N. Lakshmanan¹

Structural Durability & Health Monitoring, Vol.5, No.4, pp. 311-336, 2009, DOI:10.3970/sdhm.2009.005.311

Abstract In this paper, a two-phase strain-based constitutive model is proposed for concrete under tension. First phase deals with modelling uncracked concrete while the behaviour of concrete in cracked condition is modelled in second phase with appropriate theoretical support. A bilinear tension softening curve of concrete defined in crack width-stress space is taken as the basis to propose the model. Smeared representation of reinforcement and cracks along with multi-layered geometry definition of reinforced concrete (RC) structures is used to implement the model. Through this, it is shown that change in the orientation of tensile cracks with increasing load on the structure… More >

D.S.Liu¹, C.L.Hsu^1,2

CMC-Computers, Materials & Continua, Vol.40, No.3, pp. 165-178, 2014, DOI:10.3970/cmc.2014.040.165

Abstract To ensure the reliability of microelectronics packages, the high strain rate deformation behavior of the solder joints must be properly understood. Accordingly, the present study proposes a hybrid experimental / numerical method for determining the optimal constants of the Johnson-Cook (J-C) constitutive model for 96.5Sn-3Ag-0.5Cu (SAC305) solder alloy. In the proposed approach, FEM simulations based on the J-C model are performed to describe the load-time response of an SAC305 ball solder joint under an impact velocity of 0.5 m/s. The optimal values of the constitutive model are then determined using an iterative Genetic Algorithm approach based on a comparison of… More >

Sujuan Guo, Guozheng Kang, Juan Zhang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.4, pp. 121-122, 2011, DOI:10.3970/icces.2011.018.121

Abstract With a newly developed homogenization cyclic constitutive model of particle reinforced metal matrix composites (Guo et al., 2011), the effects of tangent operators, i.e., continuum and algorithmic tangent operators [defined by Doghri and Ouaar (2003)] on the accuracy of the developed meso-mechanical constitutive model to predict the monotonic tensile and uniaxial ratchetting deformation of SiCP/6061Al composites were investigated in this work. The predicted results were obtained by the developed model with the choices of different tangent operators and various magnitudes of loading increments. Some useful accuracy comparison and error analysis on the predicted results were conducted. It is shown that:… More >

Liu Bingfei, Dui Guansuo, Zhu Yuping

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.3, pp. 73-74, 2011, DOI:10.3970/icces.2011.017.073

Abstract Several constitutive models with different yield functions for porous shape memory alloy (SMA) are compared with the experimental date. Different approaches such as upper bound theory and lower bound theory have been adopted and a new correction formula of the yield function is proposed in this work to study the behavior of porous SMAs. Numerical results are compared with the experimental date by Zhao et al (2005). It shows that the researches using upper bound and lower bound are nearly the same and the new correction formula is much closer to the experimental data than others. More >