Xinyu Zhang¹, Wenjie Xia², Yang Wang^3,4, Liang Wang^1,*, Xiaofeng Liu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.3, pp. 3047-3061, 2024, DOI:10.32604/cmes.2023.046922

Abstract Graphene aerogel (GA), as a novel solid material, has shown great potential in engineering applications due to its unique mechanical properties. In this study, the mechanical performance of GA under high-velocity projectile impacts is thoroughly investigated using full-atomic molecular dynamics (MD) simulations. The study results show that the porous structure and density are key factors determining the mechanical response of GA under impact loading. Specifically, the impact-induced penetration of the projectile leads to the collapse of the pore structure, causing stretching and subsequent rupture of covalent bonds in graphene sheets. Moreover, the effects of temperature on the mechanical performance of… More >

Song Yuan¹, Peng Zhao^2,*, Liangpu Li^1,*, Xibao Wang¹, Jun Liu³, Bo Zhang⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.130, No.3, pp. 1683-1698, 2022, DOI:10.32604/cmes.2022.018507

Abstract The prevention and the reduction of the rockfall are the common measures of the prevention and the reduction of disasters. When the rock-shed resists the impact of the rockfall, the force that acts on the structure consists of the cushion dead load and the impact-induced load, of which the dynamic process of the propagation of the impact-induced load is complex. Therefore, we conducted a numerical study to investigate the impact of the rockfall. Considering the highly discrete characteristic of the sand, we developed a numerical model on the basis of the discrete element method (DEM). The numerical model, which simulation… More >

Dr John Dear (Lead Author)

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.2, pp. 37-38, 2011, DOI:10.3970/icces.2011.017.037

Abstract This key-note lecture is a contribution to: ICCES’11 SPECIAL SYMPOSIUM ON MODERN EXPERIMENTAL METHODS IN MECHANICS, ENGINEERING, AND THE SCIENCES (Organizing Committee Co-Chairs: Fu-Pen Chiang (USA), YiIan Kang (China), Huimin Xie (China), Xiaoyuan He (China))
Presented, in this keynote lecture, are experimental data relating to composite sand wich materials subjected to different rates of loading including explosive blast. The composite sandwich materials are manufactured using a variety of different skin and core materials. Experimental results are described for quasi-static, high-rate and explosive blast loading using DIC to identify failures processes.
An important benefit of composite sandwich materials is… More >

M.V.Hosur¹, M. M. Islam, S. Jeelani

The International Conference on Computational & Experimental Engineering and Sciences, Vol.6, No.1, pp. 81-90, 2008, DOI:10.3970/icces.2008.006.081

Abstract In this paper, low-velocity impact response of braided composites is presented. Three types of braided fabrics were used. They were:$\pm$45, 0/$\pm$45, and 0/$\pm$60. Laminates with 7 layers of$\pm$45 and 4 layers of 0/$\pm$45, and 0/$\pm$60 were fabricated by vacuum assisted resin infusion molding process to get an average thickness ranging from 2.25 to 2.4 mm. Samples of size 10$\times$ 10 cm were then cut from the panels and impacted at 10, 20 and 30 J. Impact parameters like peak load and absorbed energy were calculated and normalized for thickness. All the samples were then subjected to ultrasonic c-scan testing to… More >

Marwa Abida^1,2, Jamel Mars^3,*, Florian Gehring¹, Alexandre Vivet¹, Fakhreddine Dammak³

Journal of Renewable Materials, Vol.6, No.5, pp. 464-476, 2018, DOI:10.32604/JRM.2018.01897

Abstract Based on experimental test results, flax fiber reinforced polymer composites are characterized by nonlinear visco-elastoplastic behavior. The aim of this work is to model the quasi-unidirectional flax fiber reinforced composite behavior through a three dimensional formulation with orthotropic elasticity and orthotropic plasticity using Hill criterion. The isotropic hardening and Johnson Cook parameters are identified from unidirectional tensile tests at different strain rates. The adjustment of Hill’s yield criterion is developed based on yield stresses obtained in tensile tests at different directions. The numerical integration of the constitutive equations is implemented in a user-defined material, UMAT subroutines for the commercial finite… More >

A. M. Rajendran¹, D. J. Grove²

CMES-Computer Modeling in Engineering & Sciences, Vol.3, No.3, pp. 367-380, 2002, DOI:10.3970/cmes.2002.003.367

Abstract This paper presents detailed computational analyses investigating the ability of constitutive relationships to describe the response of a 99.5% pure alumina (AD995) subjected to a wide range of stress/strain loading states. Using a shock-wave-propagation-based finite element code, one and two-dimensional simulations were performed for the following shock and impact configurations: plate-on-plate impact; rod-on-rod impact; single-density plate-on-rod impact; graded-density plate-on-rod impact; and rod penetration into a thick plate. The detailed analyses presented in this paper include a model constant sensitivity study through comparisons of computed wave profiles with experimental measurements. More >

H. T. Liu¹, Z. D. Han¹, A. M. Rajendran², S. N. Atluri³

CMC-Computers, Materials & Continua, Vol.4, No.1, pp. 43-54, 2006, DOI:10.3970/cmc.2006.004.043

Abstract The Rajendran-Grove (RG) ceramic damage model is a three-dimensional internal variable based constitutive model for ceramic materials, with the considerations of micro-crack extension and void collapse. In the present paper, the RG ceramic model is implemented into the newly developed computational framework based on the Meshless Local Petrov-Galerkin (MLPG) method, for solving high-speed impact and penetration problems. The ability of the RG model to describe the internal damage evolution and the effective material response is investigated. Several numerical examples are presented, including the rod-on-rod impact, plate-on-plate impact, and ballistic penetration. The computational results are compared with available experiments, as well… More >

Subashini I^{1, a}, Smitha Gopinath^{2, *}, Aahrthy R^{3, b}

CMC-Computers, Materials & Continua, Vol.53, No.4, pp. 291-306, 2017, DOI:10.3970/cmc.2017.053.291

Abstract Present paper proposes a methodology by combining finite element method with smoothed particle hydrodynamics to simulate the response of textile reinforced concrete (TRC) slabs under low velocity impact loading. For the constitutive modelling in the finite element method, the concrete damaged plasticity model was employed to the cementitious binder of TRC and Von-Mises criterion was used for the textile reinforcement. Strain dependent smoothed particle hydrodynamics (SPH) was used to assess the damage and failure pattern of TRC slabs. Numerical simulation was carried out on TRC slabs with two different volume fraction of glass textile reinforcement to predict the energy absorption… More >

Qingsheng Yang^1,2, Shaochong Yang^1,3, Xiaohu Lin⁴

CMC-Computers, Materials & Continua, Vol.45, No.1, pp. 57-74, 2015, DOI:10.3970/cmc.2015.045.057

Abstract An equivalent continuum model of an isogrid structure is utilized to analyze the impact response of isogrid structures and stiffened structures. The parameters of the equivalent model are determined, and the comparison between the equivalent continuous structure and the real grid structure are examined to validate the reliability of the equivalent model. Then, the impact responses of stiffened cylindrical shells with and without an elliptical hole are investigated by using the equivalent model of grid structures. For a different location and geometry of the elliptical hole, the deformation and load-bearing capacity of the grid-stiffened cylindrical shells are studied. The numerical… More >