Acta Mechanica Sinica
The Journal covers all disciplines in the field of theoretical and applied mechanics, including solid mechanics, fluid mechanics, dynamics and control, and biomechanics. It explores analytical, computational and experimental progresses in all areas of mechanics. The Journal also encourages research in interdisciplinary subjects, and servess...
 CN 11-2063/O3 ISSN 0567-7718(Print) ISSN 1614-3116(Online) Editors-in-Chief: Professor Tian Jian Lu Professor Wei Shyy Professor Zhigang Suo Impact Factor: 1.545 Citation: Acta Mech. Sin. Frequency: Bimonthly
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 Acta Mechanica Sinica--2019, 35 (1)   Published: 20 February 2019
 FLUID MECHANICS
 Mechanism of wavy vortex and sign laws in flow past a bluff body: vortex-induced vortex L.M. Lin, S. Y. Shi, X. F. Zhong, Y. X. Wu Abstract As reported in a previous work by Lin et al. (Acta Mech Sin, 2018. https://doi.org/10.1007/s10409-018-0758-z), an interesting phenomenon was discovered based on the analysis of wavy vortex and vorticity distribution in the shear layers and near wake of a peak-perforated conic shroud, and two sign laws were summarized. In the present paper, the theory of a vortex-induced vortex is introduced to explore mechanisms in a wavy vortex and applicable sign laws for uniform and incompressible flow past a... RICH HTML
 Study on vibration of dragon wash basin and free surface waves inside Zi-Yu Guo, Xiao-Peng Chen, Lai-Bing Jia, Bin Xu Abstract We conducted experimental and numerical studies on the vibrating modes of a dragon wash basin (DWB) and the free surface waves inside the DWB. Both the vibration of the DWB and the sound produced were studied carefully. It was found that the DWB can be excited at different intrinsic modes under different excitation, including striking and rubbing it fast/slowly. However, with gentle rubbing, the DWB will be excited mainly at the first vibrating mode. We showed that the concave side wall of a DWB... RICH HTML
 Spectral measurements of hypervelocity flow in an expansion tunnel C.K. Yuan, K. Zhou, Y.F. Liu, Z.M. Hu, Z.L. Jiang Abstract Atmospheric reentry vehicles and planetary probes fly through the atmosphere at hypervelocity speed. At such speed, there is a significant proportion of heat load to the vehicle surface due to radiative heating. Accurate prediction needs a good knowledge of the radiation spectrum properties. In this paper, a high-speed camera and spectrograph coupled to an intensified charge-coupled device have been implemented to investigate the radiation flow over a semi-cylinder model. The experiments were ca... RICH HTML
 Quasi-static simulation of droplet morphologies using a smoothed particle hydrodynamics multiphase model Xiangwei Dong, Jianlin Liu, Sai Liu, Zengliang Li Abstract Numerical simulation of the morphology of a droplet deposited on a solid surface requires an efficient description of the three-phase contact line. In this study, a simple method of implementing the contact angle is proposed, combined with a robust smoothed particle hydrodynamics multiphase algorithm (Zhang 2015). The first step of the method is the creation of the virtual liquid-gas interface across the solid surface by means of dummy particles, thus the calculated surface tension near the trip... RICH HTML
 Effect of local longitudinal shortening on the transport of luminal contents through small intestine Ravi Kant Avvari Abstract A theoretical analysis of the rheological fluid flow due to peristalsis is studied. We have applied the classical lubrication theory to predict the near physiological behavior of the intestinal segment, mixing and transport. A parametric study involving the changes in local longitudinal shortening (LLS) magnitude, LLS spacing, fluid viscosity, wavelength of the wave, and occlusion of lumen caused by the wave provided insights into the dynamics of the peristalsis flow of a non-Newtonian fluid. LL... RICH HTML
 Effects of aspect ratio on shock-cylinder interaction Junfeng Ou, Zhigang Zhai Abstract Interaction of a planar shock wave with a discontinuous $\hbox {SF}_6$ elliptic gas cylinder surrounded by air is investigated. Special attention is given to the effects of aspect ratio on wave pattern, interface evolution, and material mixing. An ideal discontinuous two-dimensional gas cylinder is created by the soap film technique in experiments, and the shocked flow is captured by schlieren photography combined with a high-speed video camera. The surface of the gas cylinder is clear enough to... RICH HTML
 SOLID MECHANICS
 Dual-level stress plateaus in honeycombs subjected to impact loading: perspectives from bucklewaves, buckling and cell-wall progressive folding Lang Li, Zhenyu Zhao, Rui Zhang, Bin Han, Qiancheng Zhang, Tian Jian Lu Abstract Dual-level stress plateaus (i.e., relatively short peak stress plateaus, followed by prolonged crushing stress plateaus) in metallic hexagonal honeycombs subjected to out-of-plane impact loading are characterized using a combined numerical and analytical study, with the influence of the strain-rate sensitivity of the honeycomb parent material accounted for. The predictions are validated against existing experimental measurements, and good agreement is achieved. It is demonstrated that honeycombs... RICH HTML
 Constitutive parameters identification of thermal barrier coatings using the virtual fields method Mengmeng Zhou, Huimin Xie, Luming Li Abstract Thermal barrier coatings (TBCs) are widely applied in thermal components to protect metallic components. Owing to the complex layered structure of TBCs and difficult preparation of coating, the mechanical characterization of TBCs should be of primary importance. With regard to TBCs, this study deals with the constitutive parameters identification of bi-material. Considering the complex construction and boundary of bi material, the virtual fields method (VFM) was employed in this study. A methodo... RICH HTML
 Mechanical properties of 65Mn chiral structure with three ligaments X.W. Su, D.M. Zhu, C. Zheng, M.M. Tomovic Abstract Chiral honeycomb structures have been developed in recent years, showing excellent mechanical properties, including in-plane deformation and out-of-plane bearing and vibration isolation. In this study, the 65Mn chiral structure with three ligaments was modeled and analyzed using the finite element (FE) method. The effects of the dimensionless ligament length and dimensionless ligament thickness on the in-plane equivalent elastic modulus, equivalent Poisson's ratio, and out-of-plane shear modulus... RICH HTML
 Frictionally excited thermoelastic dynamic instability of functionally graded materials J. Liu, L. L. Ke, Y. S. Wang Abstract The perturbation method is applied to investigate the frictionally excited thermoelastic dynamic instability (TEDI) of a functionally graded material (FGM) coating in half-plane sliding against a homogeneous half-plane. We assume that the thermoelastic properties of the FGM vary exponentially with thickness. We also examine the effects of the gradient index, sliding speed, and friction coefficient on the TEDI for various material combinations. The transverse normal stress for two different coati... RICH HTML
 A three-parameter single-step time integration method for structural dynamic analysis Huimin Zhang, Yufeng Xing Abstract The existing three-parameter single-step time integration methods, such as the Generalized-$\alpha$ method, improve numerical dissipation by modifying equilibrium equation at time points, which cause them to lose accuracy due to the interpolation of load vectors. Moreover, these three-parameter methods do not present an available formulation applied to a general second-order nonlinear differential equation. To solve these problems, this paper proposes an innovative three-parameter single-step m... RICH HTML
 Nonlinear vibration analysis of a circular micro-plate in two-sided NEMS/MEMS capacitive system by using harmonic balance method Milad Saadatmand, Alireza Shooshtari Abstract In this study, forced nonlinear vibration of a circular micro-plate under two-sided electrostatic, two-sided Casimir and external harmonic forces is investigated analytically. For this purpose, at first, von Kármán plate theory including geometrical nonlinearity is used to obtain the deflection of the micro-plate. Galerkin decomposition method is then employed, and nonlinear ordinary differential equations (ODEs) of motion are determined. A harmonic balance method (HBM) is applie... RICH HTML
 Numerical and experimental analysis of the closed-cell aluminium foam under low velocity impact using computerized tomography technique S. Talebi, M. Sadighi, M. M. Aghdam Abstract In the present work, the response of closed-cell aluminum foams under low-velocity impact has been studied numerically and experimentally. Computerized tomography is employed to access three-dimensional (3D) microstructure of the closed-cell aluminum foam. Effective parameters including foam density and the velocity of impactor on foam dynamic behavior are investigated. In order to show the validity and accuracy of results, some static experiments and low-velocity impact tests have been conducte... RICH HTML
 Band gap analysis of periodic structures based on cell experimental frequency response functions (FRFs) Li-Jie Wu, Han-Wen Song Abstract An approach is proposed to estimate the transfer function of the periodic structure, which is known as an absorber due to its repetitive cells leading to the band gap phenomenon. The band gap is a frequency range in which vibration will be inhibited. A transfer function is usually performed to gain band gap. Previous scholars regard estimation of the transfer function as a forward problem assuming known cell mass and stiffness matrices. However, the estimation of band gap for irregular or compli... RICH HTML
 Buckling analysis of functionally graded plates partially resting on elastic foundation using the differential quadrature element method Arash Shahbaztabar, Koosha Arteshyar Abstract We extend the differential quadrature element method (DQEM) to the buckling analysis of uniformly in-plane loaded functionally graded (FG) plates fully or partially resting on the Pasternak model of elastic support. Material properties of the FG plate are graded in the thickness direction and assumed to obey a power law distribution of the volume fraction of the constituents. To set up the global eigenvalue equation, the plate is divided into sub-domains or elements and the generalized different... RICH HTML
 Damage and fracture model for eutectic composite ceramics Jinfeng Yu, Xinhua Ni, Xiequan Liu, Yunwei Fu, Zhihong Du Abstract Study of damage and fracture models to analyze the fracture mechanism of eutectic composite ceramics is of considerable importance because no accurate fracture models are available for these materials. Eutectic composite ceramics are composed of microcells with random direction. We present herein a model that predicts the damage and fracture of eutectic composite ceramics based on analysis of defect stability and the damage localization band. Firstly, given the microstructure of eutectic composi... RICH HTML
 Variable-stiffness composite cylinder design under combined loadings by using the improved Kriging model Jifan Zhong, Yaochen Zheng, Jianqiao Chen, Zhao Jing Abstract The large design freedom of variable-stiffness (VS) composite material presupposes its potential for wide engineering application. Previous research indicates that the design of VS cylindrical structures helps to increase the buckling load as compared to quasi-isotropic (QI) cylindrical structures. This paper focuses on the anti-buckling performance of VS cylindrical structures under combined loads and the efficient optimization design method. Two kinds of conditions, bending moment and internal... RICH HTML
 Numerical solutions for cracks in an elastic half-plane N.R. F. Elfakhakhre, N.M. A. Nik Long, Z.K. Eshkuvatov Abstract The behavior of the stress intensity factor at the tips of cracks subjected to uniaxial tension $\sigma ^{\infty }_{x}=p$ with traction-free boundary condition in half-plane elasticity is investigated. The problem is formulated into singular integral equations with the distribution dislocation function as unknown. In the formulation, we make used of a modified complex potential. Based on the appropriate quadrature formulas together with a suitable choice of collocation points, the singular integ... RICH HTML
 DYNAMICS, VIBRATION, AND CONTROL
 An R(x)-orthonormal theory for the vibration performance of a non-smooth symmetric composite beam with complex interface Chein-Shan Liu, Bo-Tong Li Abstract A composite beam is symmetric if both the material property and support are symmetric with respect to the middle point. In order to study the free vibration performance of the symmetric composite beams with different complex non-smooth/discontinuous interfaces, we develop an R(x)-orthonormal theory, where R(x) is an integrable flexural rigidity function. The R(x)-orthonormal bases in the linear space of boundary functions are constructed, of ... RICH HTML
 Instability inspection of parametric vibrating rectangular Mindlin plates lying on Winkler foundations under periodic loading of moving masses E. Torkan, M. Pirmoradian, M. Hashemian Abstract Parametric resonance is one of the most important issues in the study of dynamical behavior of structures. In this paper, dynamic instability of a moderately thick rectangular plate on an elastic foundation is investigated in the case of parametric and external resonances due to periodic passage of moving masses. The governing coupled partial differential equations (PDEs) of the system, with consideration of the first-order shear deformation theory (FSDT) or Mindlin plate theory, are presented a... RICH HTML
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