Xueling Fan^1,*, Pin Lu¹, Xiaochao Jin¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.25, No.2, pp. 1-1, 2023, DOI:10.32604/icces.2023.09919

Abstract Ni-based single crystal superalloys have been favored in the high-temperature service zones of aeroengine and gas turbine due to its excellent mechanical properties at high temperature. It is very significant to construct a constitutive model that can accurately capture the mechanical response of Ni-based single crystals for simulation analysis. In this work, a forest dislocation density-based single crystal plasticity constitutive model was developed to capture the mechanical behavior of Ni-based single crystals, including the temperature dependent anomalous yield and tension/compression asymmetry. Firstly, thermally activated cross-slip mechanism was introduced into the hardening model to describe the anomalous yield response. Secondly, the… More >

Jundong Yin¹, Lei Wang¹, Baoyin Zhu², Guodong Zhang², Dongfeng Li^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.24, No.1, pp. 1-3, 2022, DOI:10.32604/icces.2022.08750

Abstract High performance martensitic heat resistant steels are widely used in fossil fuel power plant industry due to because of their good creep resistance at high temperatures. In-depth understanding of the high temperature inelastic deformation mechanism of such steels is crucial to ensure the reliable, safe and efficient operation of the power plant [1]. The martensitic steels have a complex microstructure with a hierarchical arrangement, including a collection of packets in the prior austenite grain, blocks in the packet and laths along with dispersed nanoscale strengthening phases (e.g., MX precipitates and carbides). The purpose of this paper is to study the… More >

Yuxi Xie, Shaofan Li^*

CMES-Computer Modeling in Engineering & Sciences, Vol.129, No.3, pp. 1419-1440, 2021, DOI:10.32604/cmes.2021.016756

Abstract The microstructure of crystal defects, e.g., dislocation patterns, are not arbitrary, and it is possible that some of them may be related to the microstructure of crystals itself, i.e., the lattice structure. We call those dislocation patterns or substructures that are related to the corresponding crystal microstructure as the Geometrically Compatible Dislocation Patterns (GCDP). Based on this notion, we have developed a Multiscale Crystal Defect Dynamics (MCDD) to model crystal plasticity without or with minimum empiricism. In this work, we employ the multiscale dislocation pattern dynamics, i.e., MCDD, to simulate crystal plasticity in body-centered cubic (BCC) single crystals, mainly α-phase… More >

C. A. Bronkhorst^1,2, A. R. Ross³, B. L. Hansen¹, E. K. Cerreta², J. F. Bingert²

CMC-Computers, Materials & Continua, Vol.17, No.2, pp. 149-174, 2010, DOI:10.3970/cmc.2010.017.149

Abstract A common sample geometry used to study shear localization is the "tophat": an axi-symmetric sample with an upper "hat" portion and a lower "brim" portion. The gage section lies between the hat and brim. The gage section length is on the order of 0.9 mm with deformation imposed through a Split-Hopkinson Pressure Bar system at maximum top-to-bottom velocity in the range of 10-25 m/sec. Detailed metallographic analysis has been performed on sections of the samples to quantify the topology and deformation state of the material after large deformation shear. These experiments performed with polycrystalline tantalum have been modeled using a… More >

Fabien Briffod*, Alexandre Bleuset, Takayuki Shiraiwa, Manabu Enoki

The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 125-125, 2019, DOI:10.32604/icces.2019.05319

Abstract The fatigue behavior of metallic materials is a multi-scale problem (from a time and length-scale perspective) intimately influenced by microstructural features that determine the early stages of crack propagation. Prediction of fatigue life is traditionally based on the evaluation of macroscopic mechanical fields at the structure level and on the application of empirical rules. However, these structure-oriented methods are material-specific and do not consider the material variability at lower scales. Hence, reliable prediction of fatigue performances and its variability requires on one side the characterization and quantification of early damage mechanisms and on the other side the incorporation of local… More >

T. Hasebe¹

CMES-Computer Modeling in Engineering & Sciences, Vol.11, No.3, pp. 145-156, 2006, DOI:10.3970/cmes.2006.011.145

Abstract This paper presents recent achievements in field theoretical approach toward substantial linkage among key hieratical scales dominating polycrystalline plasticity of metals and alloys. Major ingredients of the theory are briefly shown first, which is followed by several overwhelming results and some implications including key factors for dislocation cell structure evolution, key features of polycrystalline plasticity and their rational modeling in crystal plasticity-based constitutive equation. More >

Hamad F. Al-Harbi¹, Marko Knezevic^1,2, Surya R. Kalidindi^1,3

CMC-Computers, Materials & Continua, Vol.15, No.2, pp. 153-172, 2010, DOI:10.3970/cmc.2010.015.153

Abstract In recent work, we have demonstrated the viability and computational advantages of DFT-based spectral databases for facilitating crystal plasticity solutions in face-centered cubic (fcc) metals subjected to arbitrary deformation paths. In this paper, we extend and validate the application of these novel ideas to body-centered cubic (bcc) metals that exhibit a much larger number of potential slip systems. It was observed that the databases for the bcc metals with a larger number of slip systems were more compact compared to those obtained previously for fcc metals with a smaller number of slip systems. Furthermore, we demonstrate in this paper that… More >

XL Geng¹, KS Zhang², YQ Guo¹, L Qin¹

CMC-Computers, Materials & Continua, Vol.13, No.1, pp. 1-16, 2009, DOI:10.3970/cmc.2009.013.001

Abstract One of the problems in a micro-forming process is the grain size effect, which means the formed part consists of a single grain or several grains sometimes, so the material shows anisotropic or heterogeneous. Under these conditions, a conventional method, which based on the isotropic and homogeneous material hypothesis, is not suitable. In this paper, Experimental investigations into micro deep drawing of the copper single crystal were carried out and the pattern of the micro-cup and the drawing force were observed. Using crystal plasticity theory, a user material subroutine (VUMAT) was built and linked to ABAQUS, and the micro deep… More >