Ying Xu¹, Shengping Shen^1,2

CMC-Computers, Materials & Continua, Vol.28, No.1, pp. 81-96, 2012, DOI:10.3970/cmc.2012.028.081

Abstract This paper considers the surface effect through the surface and bulk electric Gibbs free energy. The analytical expressions are derived for the effective elastic, dielectric and piezoelectric modulus for nano-structural elements in electromechanical coupling problems. Numerical examples for PZT are given to illustrate the size effects on the electromechanical properties of nano-particles, nano-wires and nano-films quantitatively. The solution shows that the electromechanical properties of piezoelectric nano-material are size-dependent but the size effects on the elastic property and dielectric property are different. More >

Ligia Munteanu¹, Veturia Chiroiu¹

CMC-Computers, Materials & Continua, Vol.28, No.1, pp. 57-80, 2012, DOI:10.3970/cmc.2012.028.057

Abstract This paper discusses the modeling and feedforward control of hysteresis in a Cantor-like piezoelectric plate. The generalized play operator is analyzed in connection with the plate equations. Results show that hysteresis can be reduced to less than 40% when applying the feedforward control. The subject of the paper belongs to the field of dynamics, characterization and control at the micro/nanoscale. The choose of the Cantor-like piezoelectric plate is motivated by its special property to generate the subharmonic waves due to the anharmonic coupling between the extended-vibration (phonon) and the localized-mode (fracton) regimes. This behavior is a benefit for several applications… More >

Zhen Luo^1,2, Nong Zhang,^1,3

CMC-Computers, Materials & Continua, Vol.28, No.1, pp. 27-56, 2012, DOI:10.3970/cmc.2012.028.027

Abstract This paper attempts to present a new multi-criteria topological optimization methodology for the systematic design of compliant micro-mechanisms. Instead of employing only the strain energy (SE) or the functional specifications such as mechanical efficiency (ME), in this study an alternative formulation representing multiple design requirements is included in the optimization to describe the performance of compliant mechanisms. In most conventional designs, SE is used to only measure the design requirement from the point of view of structures, while ME is usually applied to describe the mechanical performance of mechanisms. However, the design of a compliant mechanism is required to comprehensively… More >

Q. Wang¹, Y. Miao^1,2, H.P. Zhu¹, C. Zhang³

CMC-Computers, Materials & Continua, Vol.28, No.1, pp. 1-26, 2012, DOI:10.3970/cmc.2012.028.001

Abstract The Hybrid boundary node method (Hybrid BNM) is a boundary type meshless method which based on the modified variational principle and the Moving Least Squares (MLS) approximation. Like the boundary element method (BEM), it has a dense and unsymmetrical system matrix and needs to be speeded up while solving large scale problems. This paper combines the fast multipole method (FMM) with Hybrid BNM for solving 3D elasticity problems. The formulations of the fast multipole Hybrid boundary node method (FM-HBNM) which based on spherical harmonic series are given. The computational cost is estimated and an O(N) algorithm is obtained. The algorithm… More >

C. Jiang^1,2, X. Han¹, D. Li³

CMC-Computers, Materials & Continua, Vol.27, No.3, pp. 275-304, 2012, DOI:10.3970/cmc.2011.027.275

Abstract For optimization or decision-making problems with interval uncertainty, the interval comparison relation plays a very important role, as only based on it a better or best decision can be determined. In this paper, a new kind of interval comparison relation termed as reliability-based possibility degree of interval is proposed to give quantitative evaluations on "how much better" of one interval than another, which is more suitable for engineering reliability analysis and numerical computation than the existing relations. In the new relation, the range of the comparing values is extended into the whole real number field, and the precise comparison is… More >

E. Ferretti¹, M.C. Bignozzi²

CMC-Computers, Materials & Continua, Vol.27, No.3, pp. 231-274, 2012, DOI:10.3970/cmc.2011.027.231

Abstract In this study, the results of an in-situ experimental program on the performance of concrete taxiways are presented. The experimental program has been undertaken at the Guglielmo Marconi airport of Bologna (Italy). It concerns two portions of the taxiway, one built with plain concrete and one with rubberized concrete. Each portion has been instrumented with strain gauges embedded in concrete for the acquisition of vertical strains. The results of the experimentation are discussed in view of possible applications to the computational analysis of the stress field induced into pavements by aircrafts. More >

Raghvendra Khedle¹, D.P.Mondal², S.N.Verma¹, Sanjay Panthi²

CMC-Computers, Materials & Continua, Vol.27, No.3, pp. 211-230, 2012, DOI:10.3970/cmc.2011.027.211

Abstract The interface in aluminum cenosphere syntactic foam (ACSF) is modeled using FEM to study its deformation behaviour as a function of interface characteristics such as interface stiffness and thickness. The interface is modeled as a thin layer of object. The effective modulus and stress of ACSF examined when it contain 50% cenosphere by volume. In this study, the shell wall thickness of cenosphere is fixed at 1µm. The width of the interface varies from 0.2% to 0.6% of cenosphere volume fraction. The interface strength and modulus varies in the range of 10 to 50% of the matrix alloy. The values… More >

Seon Doo Jo¹, Chan Kyu Park², Jae Hong Jeong², Seung Hoon Lee², Seung Hee Kwon³

CMC-Computers, Materials & Continua, Vol.27, No.3, pp. 189-210, 2012, DOI:10.3970/cmc.2011.027.189

Abstract When concrete is being pumped, a lubricating layer forms at the interface of the inner concrete and the wall of the pipe. The lubricating layer is one of the most dominant factors in determining the pumping capability, yet no study has endeavored to quantitatively estimate the thickness and rheological properties of the layer. Recently, there has been a growing demand for large-scale construction under extreme conditions, such as high-rise buildings and super-long span bridges. This demand has heightened the need for more accurate predictions of pumpability.
A possible mechanism that contributes to the formation of the lubricating layer is shear-induced… More >

Jing Qian¹, Xuhong Miao², Yao Shen³

CMC-Computers, Materials & Continua, Vol.27, No.2, pp. 179-188, 2012, DOI:10.32604/cmc.2012.027.179

Abstract Based on experimental data, the research work on warp knitted spacer fabrics gives compression laws when structural parameters (such as diameter of spacer yarn, areal density, spacer yarn angle and the thickness of spacer fabrics ) of spacer fabric change. ANSYS calculation models were developed, and simulation results matched with experimental data well. The computer simulation on this area provides a fundamental tool which can help designer to decide structural parameters when working stresses are given. More >

Zone-Ching Lin¹, Ying-Chih Hsu¹

CMC-Computers, Materials & Continua, Vol.27, No.2, pp. 143-178, 2012, DOI:10.32604/cmc.2012.027.143

Abstract This paper uses quasi-steady molecular statics method to carry out simulation of nanoscale orthogonal cutting of single-crystal copper workpiece by the diamond tools with different edge shapes. Based on the simulation results, this paper analyzes the cutting force, equivalent stress and strain, and temperature field. For the three-dimensional quasi-steady molecular statics nanocutting model used by this paper, when the cutting tool moves on a workpiece, displacement of atoms is caused due to the effects of potential on each other. After a small distance that each atom moves is directly solved by the calculated trajectory of each atom, the concept of… More >