Open Access
ARTICLE
Wen-Hwa Chen1,2, Shu-Ru Lin2, Kuo-Ning Chiang2,3
CMC-Computers, Materials & Continua, Vol.2, No.3, pp. 151-162, 2005, DOI:10.3970/cmc.2005.002.151
Abstract As ultra-fine-pitch technologies are adopted to enhance the performance of electronic packaging, solder bridging becomes an urgently serious defect. This work presents a computational model using the Surface Evolver program to analyze the stability of solder bridging for area array type packaging. Several factors that affect the stability of solder bridging spanning two identical circular pads are considered herein, including the pad size, the total volume of solder bumps, the pitch between adjacent pads, the contact angle between the molten solder alloy and the pad, the contact angle between the molten solder alloy and the solder mask and the surface… More >
Open Access
ARTICLE
N. Ramakrishnan1, P. Rama Rao2
CMC-Computers, Materials & Continua, Vol.2, No.3, pp. 163-176, 2005, DOI:10.3970/cmc.2005.002.163
Abstract Ductile fracture is initiated by void nucleation at a characteristic distance (Ic) from the crack tip and propagated by void growth followed by coalescence with the tip. The earlier concepts expressed Ic in terms of grain size or inter-particle distance because grain and particle boundaries form potential sites for void nucleation. However, Srinivas et al. (1994) observed nucleation of such voids even inside the crack tip grains in a nominally particle free Armco iron. In an attempt to achieve a unified understanding of these observations, typical crack-tip blunting prior to ductile fracture in a standard C(T) specimen (Mode I) was… More >
Open Access
ARTICLE
S.Yu. Reutskiy1
CMC-Computers, Materials & Continua, Vol.2, No.3, pp. 177-188, 2005, DOI:10.3970/cmc.2005.002.177
Abstract In this paper a new meshless method for eigenproblems with Laplace and biharmonic operators in simply and multiply connected domains is presented. The solution of an eigenvalue problem is reduced to a sequence of inhomogeneous problems with the differential operator studied. These problems are solved using the method of fundamental solutions. The method presented shows a high precision in simply and multiply connected domains. The results of the numerical experiments justifying the method are presented. More >
Open Access
ARTICLE
C. Shu1,2, W. X. Wu2, C. M. Wang3
CMC-Computers, Materials & Continua, Vol.2, No.3, pp. 189-200, 2005, DOI:10.3970/cmc.2005.002.189
Abstract This paper demonstrates the application of a meshfree least square-based finite difference (LSFD) method for analysis of metallic waveguides. The waveguide problem is an eigenvalue problem that is governed by the Helmholtz equation. The second order derivatives in the Helmholtz equation are explicitly approximated by the LSFD formulations. TM modes and TE modes are calculated for some metallic waveguides with different cross-sectional shapes. Numerical examples show that the LSFD method is a very efficient meshfree method for waveguide analysis with complex domains. More >
Open Access
ARTICLE
X.G. Yuan1,2, R.J. Zhang2
CMC-Computers, Materials & Continua, Vol.2, No.3, pp. 201-212, 2005, DOI:10.3970/cmc.2005.002.201
Abstract Cavity formation and growth in a class of incompressible transversely isotropic nonlinearly elastic solid spheres are described as a bifurcation problem, for which the strain energy density is expressed as a nonlinear function of the invariants of the right Cauchy-Green deformation tensor. A bifurcation equation that describes cavity formation and growth is obtained. Some interesting qualitative properties of the bifurcation equation are presented. In particular, cavitated bifurcation is examined for a solid sphere composed of an incompressible anisotropic Gent-Thomas material model with a transversely isotropy about the radial direction. The effect of constitutive parameters on cavity formation and growth is… More >
Open Access
ARTICLE
Yunfa Zhang1, Zihui Xia1,2
CMC-Computers, Materials & Continua, Vol.2, No.3, pp. 213-226, 2005, DOI:10.3970/cmc.2005.002.213
Abstract In the present study, the initiation and evolution of the interphase damage and their influences on the global stress-strain relation of composite laminates are predicted by finite element analysis on a micromechanical unit cell model. A thin layer of interphase elements is introduced and its stress-strain relation is derived based on a cohesive law which describes both normal and tangential separations at the interface between the fiber and matrix. In addition, a viscous term is added to the cohesive law to overcome the convergence difficulty induced by the so-called snap-back instability in the numerical analysis. The matrix behavior is described… More >