Chunwei Zhao^1,2, Xianghe Peng^1,2,3, Jin Huang⁴, Ning Hu^1,5,6

CMC-Computers, Materials & Continua, Vol.30, No.3, pp. 219-236, 2012, DOI:10.3970/cmc.2012.030.219

Abstract The validity of the two conventional micro-macro descriptions for MRFs, based respectively on the exact dipole model and the simplified dipole model, is examined with the results obtained with the commercially available finite element (FE) code ANSYS. It is found that although the simplified dipole model can match better the result by FE computation, there is still a marked difference. An enhanced dipole model is then suggested, which takes into account the contribution of the magnetized particles to magnetic field. Making use of a statistical approach and neglecting the interaction between particle chains, a micro-macro More >

K.W. Luczynski¹, A. Dejaco¹, O. Lahayne¹, J. Jaroszewicz², W.Swieszkowski², C. Hellmich¹

CMES-Computer Modeling in Engineering & Sciences, Vol.87, No.6, pp. 505-529, 2012, DOI:10.3970/cmes.2012.087.505

Abstract A 71 volume-% macroporous tissue engineering scaffold made of poly-l-lactide (PLLA) with 10 mass-% of pseudo-spherical tri-calcium phosphate (TCP) inclusions (exhibiting diameters in the range of several nanometers) was microCT-scanned. The corresponding stack of images was converted into regular Finite Element (FE) models consisting of around 100,000 to 1,000,000 finite elements. Therefore, the attenuation-related, voxel-specific grey values were converted into TCP-contents, and the latter, together with nanoindentation tests,entered a homogenization scheme of the Mori-Tanaka type, as to deliver voxel-specific (and hence, finite element-specific) elastic properties. These FE models were uniaxially loaded, giving access to the… More >

Shaw-Jyh Shin¹, Chen-Hung Huang², Y.C. Shiah³

CMES-Computer Modeling in Engineering & Sciences, Vol.40, No.1, pp. 83-104, 2009, DOI:10.3970/cmes.2009.040.083

Abstract Owing to the CTE (Coefficient of Thermal Expansion) mismatch among solder joints, IC (Integrated Circuit) chip, and PCB (Printed Circuit Board), electronic packages shall experience fatigue failure after going though a period of thermal cycling. As a major means to enhance the reliability of the solder joints, underfill is often dispensed to fill the gap between the die and the substrate. This study aims at investigating how the underfill may affect the thermal fatigue life of WLCSP (Wafer Level Chip Scale Package) by means of FEA (finite element analysis). In this study, the thermal fatigue More >

Dyi-Cheng¹, Syuan-Yi Syong¹

CMC-Computers, Materials & Continua, Vol.13, No.3, pp. 191-200, 2009, DOI:10.3970/cmc.2009.013.191

Abstract Finite element simulations are performed to investigate the plastic deformation behavior of Ti-6Al-4V titanium alloy during its indirect extrusion through a four-hole die. The simulations assume the die, mandrel and container to be rigid bodies and ignore the temperature change induced during the extrusion process. Under various extrusion conditions, the present numerical analysis investigates the effective stress and profile of product at the exit. The relative influences of the friction factors, the temperature of billet and the eccentricity of four-hole displacement are systematically examined. The simulations focus specifically on the effects of the friction factor, More >

D. H. Pahr¹, H.J. Böhm¹

CMES-Computer Modeling in Engineering & Sciences, Vol.34, No.2, pp. 117-136, 2008, DOI:10.3970/cmes.2008.034.117

Abstract The combination of heterogeneous volume elements and numerical analysis schemes such as the Finite Element method provides a powerful and well proven tool for studying the mechanical behavior of composite materials. Periodicity boundary conditions (PBC), homogeneous displacement boundary conditions (KUBC) and homogeneous traction boundary conditions (SUBC) have been widely used in such studies. Recently Pahr and Zysset (2008) proposed a special set of mixed uniform boundary conditions (MUBC) for evaluating the macroscopic elasticity tensor of human trabecular bone. These boundary conditions are not restricted to periodic phase geometries, but were found to give the same… More >

Nishioka T.¹, sugami M.¹, Fujimoto T.¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.1, No.3, pp. 119-126, 2007, DOI:10.3970/icces.2007.001.119

Abstract In this paper, the simulations of fatigue crack propagation and dynamic fracture path prediction are carried out for specimens containing circular holes or inclusions, using the moving finite element method based on Delaunay automatic triangulation. And, we compared the numerical results with the experimental results. More >