Di Qiu^1,3,4, Rongpei Shi^2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.1, pp. 1017-1028, 2024, DOI:10.32604/cmes.2024.048797

Abstract For media with inclusions (e.g., precipitates, voids, reinforcements, and others), the difference in lattice parameter and the elastic modulus between the matrix and inclusions cause stress concentration at the interfaces. These stress fields depend on the inclusions’ size, shape, and distribution and will respond instantly to the evolving microstructure. This study develops a phase-field model concerning modulus heterogeneity. The effect of modulus heterogeneity on the growth process and equilibrium state of the α plate in Ti-6Al-4V during precipitation is evaluated. The α precipitate exhibits strong anisotropy in shape upon cooling due to the interplay of the elastic strain and interfacial… More >

Yanhua Zhao^1,3,*, Wenhao Tian¹, Jianhua Liu¹, Dongqing Qian², Wei Meng¹, Jiaming Wang¹

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.2, pp. 451-470, 2023, DOI:10.32604/fdmp.2022.021035

Abstract The process parameters of laser additive manufacturing have an important influence on the forming quality of the produced items or parts. In the present work, a finite element model for simulating transient heat transfer in such processes has been implemented using the ANSYS software, and the temperature and stress distributions related to 316L stainless steel thin-walled ring parts have been simulated and analyzed. The effect of the laser power, scanning speed, and scanning mode on temperature distribution, molten pool structure, deformation, and stress field has been studied. The simulation results show that the peak temperature, weld pool size, deformation, and… More >

Yueqiang Yu¹, Tingang Ma¹, Suling Wang^1,*, Minzheng Jiang¹, Yanling Guo^2,3, Ting Jiang^1,*, Shuaiqi Huang¹, Ziming Zheng¹, Bo Yan¹, Jiyuan Lv¹

Journal of Renewable Materials, Vol.11, No.1, pp. 333-347, 2023, DOI:10.32604/jrm.2022.022296

Abstract A calculation model of stress field in laser additive manufacturing of walnut shell composite powder (walnut shell/Co-PES powder) was established. The DFLUX subroutine was used to implement the moveable application of a double ellipsoid heat source by considering the mechanical properties varying with temperature. The stress field was simulated by the sequential coupling method, and the experimental results were in good accordance with the simulation results. In addition, the distribution and variation of stress and strain field were obtained in the process of laser additive manufacturing of walnut shell composite powder. The displacement of laser additive manufacturing walnut shell composite… More > Graphic Abstract

Miaocao Wang¹, Yuhua Huang¹, Jinming Li¹, Ling Xu², Fulong Zhu^1,*

CMC-Computers, Materials & Continua, Vol.68, No.1, pp. 743-759, 2021, DOI:10.32604/cmc.2021.016372

Abstract From an ingot to a wafer then to a die, wafer thinning plays an important role in the semiconductor industry. To reveal the material removal mechanism of semiconductor at nanoscale, molecular dynamics has been widely used to investigate the grinding process. However, most simulation analyses were conducted with a single phase space trajectory, which is stochastic and subjective. In this paper, the stress field in wafer thinning simulations of 4H-SiC was obtained from 50 trajectories with spatial averaging and phase space averaging. The spatial averaging was conducted on a uniform spatial grid for each trajectory. A variable named mask was… More >

Jianrui Zhang^1,2, Min Chi¹, Bo Qian^1,*, Zhijun Qiu²

CMES-Computer Modeling in Engineering & Sciences, Vol.125, No.1, pp. 77-94, 2020, DOI:10.32604/cmes.2020.010518

Abstract To accurately perform the coupled simulation of temperature field and stress field of complex parts and porous structures under the optimal manufacturing process parameters, three kinds of porous structures with different complexity were designed in this paper. Firstly, ANSYS additive software was used to conduct the stress/deformation simulation of the whole structure under different scanning strategies. Secondly, the optimal scanning strategy for different porous structures was determined, then the experimental preparation was performed, and mechanical properties of compression were tested and studied. The results show that the elastic modulus and yield strength increase with the increase of pole diameter/wall thickness.… More >

Kei Saito^{1, 2, *}, Tei Hirashima¹, Ninshu Ma^{2, *}, Hidekazu Murakawa²

CMES-Computer Modeling in Engineering & Sciences, Vol.122, No.2, pp. 415-432, 2020, DOI:10.32604/cmes.2020.08847

Abstract A characteristic tensor is defined using stress tensor averaged in a small circular domain at the crack tip and multiplied by the root of domain radius. It possesses the original stress tensor characteristics and has a simple relationship with conventional fracture-mechanics parameters. Therefore, it can be used to estimate stress intensity factors (SIFs) for cracks of arbitrary shape subjected to multiaxial stress loads. A characteristic tensor can also be used to estimate SIFs for kinked cracks. This study examines the relation between a characteristic tensor and SIFs to demonstrate the correlation between the characteristic tensor and fracture-mechanics parameters. Consequently, a… More >

Satoshi Ii^1,*, Keisuke Ito¹, Naoya Takakusaki¹, Naoya Sakamoto¹

Molecular & Cellular Biomechanics, Vol.16, Suppl.2, pp. 49-49, 2019, DOI:10.32604/mcb.2019.07378

Abstract Cells adhere to a substrate and generate traction forces in focal adhesions that enable them to apprehend extracellular mechanical properties [1]. Current concerns are focused on mechanisms how the mechanical balances hold in the cell and affect the cell behavior, and therefore non-invasive measurement techniques for the cell traction forces are required. The cell traction force microscopy (TFM) generalized by Dembo and Wang [2] is an attractive approach to non-invasively estimate cell traction force fields, in which an inverse problem is solved using a mechanical model of the substrate and displacement fields from fluorescent images of immersed beads in the… More >

Hai Qian^1,*, Sai-Huen Lo², Ding Zhou³, Yang Yang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.1, pp. 215-247, 2019, DOI:10.32604/cmes.2019.07922

Abstract The temperature and the stress distribution in simply-supported laminated cylindrical shells undergo thermal loads on the surface have been investigated. Exact solutions of physical quantities including temperature, heat flux, thermal displacement and stress are developed for the cylindrical laminated shell. Cylindrical shells are partitioned into more thin layers. In cylindrical coordinate, analytical expressions for physical quantities inside each layer are derived. Taking into account the compatibility of physical quantities at the interfaces, the relations between the outer and the inner layer of the laminated shell can be described with a transfer matrix. The undetermined parameters from the solutions of each… More >

Shuncai Li, Zhengzhu Dong, Dan Ma.

The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.3, pp. 93-94, 2011, DOI:10.3970/icces.2011.016.093

Abstract Roadway with local short supporting is not only a common phenomenon in engineering, but also short of in-depth theoretical study. Existing literature on underground stress field theory of surrounding rock, generally gives the analytical solution of stress for the surrounding rock of roadway with uniform supporting or no supporting, but doesn't give a corresponding stress solution for local supporting or local short supporting. Based on the circular roadway local short supporting mechanical model, according to the boundary element method of bi-harmonic boundary value problem of exterior circular domain, the boundary integral formula of Airy stress function is deduced for the… More >

Vijaya Bhaskar Chalivendra¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.5, No.1, pp. 27-34, 2008, DOI:10.3970/icces.2008.005.027

Abstract Asymptotic analysis coupled with Westergaard stress function approach is used to develop quasi-static stress fields for a crack oriented along one of the principal axes of inhomogeneous orthotropic medium. In the formulation, four independent engineering constants, E₁₁, E₂₂, G₁₂, v₁₂ are replaced by an effective stiffness E = √E₁₁E₂₂, a stiffness ratio δ = (E₁₁/E₂₂), an effective Poisson's ratio v = √v₁₂v₂₁, and a shear parameter k = (E/2G₁₂)-v. It is assumed that the effective stiffness varies exponentially along one of the principal axes of orthotropy. The first two terms in the expansion of stress field are derived to explicitly… More >