S. Atobe¹, H. Fukunaga¹, N. Hu²

CMC-Computers, Materials & Continua, Vol.26, No.1, pp. 67-90, 2011, DOI:10.3970/cmc.2011.026.067

Abstract This paper presents a method for identifying the location and force history of an impact force acting on CFRP structures such as laminated plates and stiffened panels. The identification method is an experimental one without using any analytical model of the structure. Here, experimental transfer matrices, which relate the impact force to the corresponding responses of PZT sensors, are used to identify the impact force. The transfer matrices are preliminarily constructed from the measured data obtained by impact tests with an impulse hammer. To identify the impact location, the arrival times of the flexural waves to the PZT sensors are… More >

M.N.D. Cherief¹, M. Elmeguenni¹, M. Benguediab¹

CMC-Computers, Materials & Continua, Vol.51, No.3, pp. 187-201, 2016, DOI:10.3970/cmc.2016.051.187

Abstract Impact behavior of polymers has received considerable attention in recent years, and much work based on fracture mechanic approaches has been carried out. In this paper, fracture behavior in large deformation of a high density polyethylene (HDPE) materials was investigated through experimental impact testing on single edge notched specimen (SENB) and by using theoretical and analytical fracture criteria concepts. Moreover, a review of the main fracture criteria is given in order to characterize the toughness of this polymer in the both cases (static and dynamic). The fractured specimens obtained from the Charpy impact test were characterized with respect to their… More >

B. Šavija¹, E. Schlangen¹

CMC-Computers, Materials & Continua, Vol.48, No.3, pp. 181-202, 2015, DOI:10.3970/cmc.2015.048.181

Abstract In this paper, a novel approach for simulating in-plane vibration of thin plates is proposed. It is based on the spectral element method (SEM) used within a lattice modeling framework. First, derivation of a frequency dependent dynamic stiffness matrix for a spectral beam element is presented. Then, the lattice modeling concept is introduced. In the model, the two-dimensional plate is discretized as a set of (one dimensional) spectral beam elements connected at the ends. The proposed approach is then used for modal analysis of rectangular plates of different aspect ratios (1 and 2) and boundary conditions (completely free and clamped).… More >

Zhengzheng Cao¹, Yuejin Zhou^1,2

CMC-Computers, Materials & Continua, Vol.48, No.2, pp. 77-90, 2015, DOI:10.3970/cmc.2015.048.077

Abstract Reasonable width design of narrow coal pillar is the key for ensuring stability of surrounding rock in the roadway driving along next goaf. Based on movement characteristics of overlying strata in gob-side entry, the paper establishes the mechanical model of surrounding rock structure for roadway driving along next goaf, and analyzes the interaction mechanism between key blocks and coal pillar. Besides, in allusion to the mechanical equilibrium of key block B in basic roof, the stability coefficients K₁ and K₂ of key block B and sensitive coefficient of influencing factor are introduced. When the stability coefficient K₁ is larger than… More >

Cao Zhengzheng¹, Zhou Yuejin^1,2, Zhang Qi¹, Wang Erqian¹

CMC-Computers, Materials & Continua, Vol.47, No.3, pp. 203-215, 2015, DOI:10.3970/cmc.2015.047.203

Abstract Gas fracturing technology is the key to the exploration for unconventional petroleum resources and other engineering industries, so the research on the coupled gas-solid-thermal model during rock damage has the important significance to the development of gas fracturing technology. By introducing rock damage variable, the coupled gas-solid-thermal model during rock damage is established in this paper, besides, the rock damage constitutive is written with MATLAB software, which is embedded in the multi-physics coupling software COMSOL in the process of numerical computation. Based on this, the damage rule of rock mass around drilling under high pressure gas is analyzed. The results… More >

Shasha Yang, Shengping Shen¹

CMC-Computers, Materials & Continua, Vol.40, No.3, pp. 219-239, 2014, DOI:10.3970/cmc.2014.040.219

Abstract As well known, gradient theories can describe size effects that are important in nano-scale problems. In this paper, we analyze the Eshelby-type anti-plane inclusion problem embedded in infinite dielectric body by considering both strain gradient and electric field gradient effects to account for the size effect and high-order electromechanical coupling effect. The size-dependent Eshelby and Eshelby-like tensor, strain, stress, electric field and electric displacement components are derived explicitly by means of Green's function method. Theoretical results indicate that strain and electric field are decoupled for anti-plane inclusion problem while stress field and electric displacement are coupled through strain gradient and… More >

Y. Zhang¹, Y. F. Nie², Y. T. Wu¹

CMC-Computers, Materials & Continua, Vol.40, No.3, pp. 203-218, 2014, DOI:10.3970/cmc.2014.040.203

Abstract The present study aims to evaluate the mechanical properties of steel fiber reinforced concrete (SFRC) by the statistical second-order two-scale (SSOTS) method. At first, the representation for microstructure of SFRC is described by a concept of statistical screen. According to the microstructure representation, the SSOTS method is displayed in a concise way. This method is on the basis of asymptotic expansion homogenization and Monte Carlo method, and can calculate the local strain and stress field through the two-order displacement solution. As the classical homogenization method, the expression of homogenized elastic modulus is derived analytically. Then combined with the appropriate strength… More >

Mohamed I. A. Othman¹, Magda E. M. Zidan¹, Mohamed I. M. Hilal¹

CMC-Computers, Materials & Continua, Vol.40, No.3, pp. 179-201, 2014, DOI:10.3970/cmc.2014.040.179

Abstract This investigation is aimed to study the two dimensional problem of thermoelastic medium with voids under the effect of the gravity. The modulus of elasticity is taken as a linear function of the reference temperature and employing the two-temperature generalized thermoelasticity. The problem is studied in the context of Green-Naghdi (G-N) theory of types II and III. The normal mode analysis method is used to obtain the exact expressions for the physical quantities which have been shown graphically by comparison between two types of the (G-N) theory in the presence and the absence of the gravity, the temperature dependent properties… 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 >

C. A. Bronkhorst^1,2, A. R. Ross³, B. L. Hansen¹, E. K. Cerreta², J. F. Bingert²

CMC-Computers, Materials & Continua, Vol.17, No.2, pp. 149-174, 2010, DOI:10.3970/cmc.2010.017.149

Abstract A common sample geometry used to study shear localization is the "tophat": an axi-symmetric sample with an upper "hat" portion and a lower "brim" portion. The gage section lies between the hat and brim. The gage section length is on the order of 0.9 mm with deformation imposed through a Split-Hopkinson Pressure Bar system at maximum top-to-bottom velocity in the range of 10-25 m/sec. Detailed metallographic analysis has been performed on sections of the samples to quantify the topology and deformation state of the material after large deformation shear. These experiments performed with polycrystalline tantalum have been modeled using a… More >