Thanh Thuong Huynh¹, Tien V. T. Nguyen^2,3, Quoc Manh Nguyen⁴, Trieu Khoa Nguyen^2,*

CMC-Computers, Materials & Continua, Vol.68, No.3, pp. 2913-2923, 2021, DOI:10.32604/cmc.2021.016064 - 06 May 2021

Abstract In this study, we investigated warpage and corner lifting minimization for three-dimensional printed parts generated by macro-size fused deposition modeling (FDM). First, the reasons for warpage were theoretically elucidated. This approach revealed that the thermal deformation and differential volumetric shrinkage of the extruded molten plastic resulted in warpage of FDM parts. In addition, low adhesion between the deposited model and the heated or non-heated printing bed may intensify warpage further. As a next step, initial small-size and medium-size models were used to identify parameters to manage and minimize warpage in a way that would reduce… More >

Ying Wang^1,*, Zheng Yan¹, Zhen Wang²

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.2, pp. 549-574, 2021, DOI:10.32604/cmes.2021.014727 - 19 April 2021

Abstract Due to the complex structure and dense weld of the orthotropic steel bridge deck (OSBD), fatigue cracks are prone to occur in the typical welding details. Welding residual stress (WRS) will cause a plastic zone at the crack tip. In this paper, an elastoplastic constitutive model based on the Chaboche kinematic hardening model was introduced, and the extended finite element method (XFEM) was used to study the influence of material elastoplasticity and crack tip plastic zone on the law of fatigue crack propagation. By judging the stress state of the residual stress field at the… More >

R. Kalaivanan¹, N. Vishnu Ganesh², Qasem M. Al-Mdallal^3,*

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.2, pp. 319-332, 2021, DOI:10.32604/fdmp.2021.012789 - 02 April 2021

Abstract The buoyancy driven flow of a second-grade nanofluid in the presence of a binary chemical reaction is analyzed in the context of a model based on the balance equations for mass, species concentration, momentum and energy. The elastic properties of the considered fluid are taken into account. The two-dimensional slip flow of such non-Newtonian fluid over a porous flat material which is stretched vertically upwards is considered. The role played by the activation energy is accounted for through an exponent form modified Arrhenius function added to the Buongiorno model for the nanofluid concentration. The effects More >

Kengo Fujii¹, Satoru Yoneyama¹, Ayaka Suzuki², Hiroshi Yamada²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.23, No.1, pp. 21-21, 2021, DOI:10.32604/icces.2021.08538

Abstract This study establishes a method to measure the displacement and strain of rubber with large and fast deformations using digital image correlation. In order to elucidate the mechanism of growth of a crack and to investigate the complex behavior of a crack tip, which is important for that purpose, displacement and strain near the crack where large strains are locally generated by stress concentration are measured. A displacement restraint rubber sheet of a strip fixed at upper and lower ends with an initial crack is used as a test piece. A constant rate displacement load… More >

Jurica Sorić^*, Boris Jalušić, Tomislav Lesičar, Filip Putar, Zdenko Tonković

The International Conference on Computational & Experimental Engineering and Sciences, Vol.23, No.1, pp. 1-1, 2021, DOI:10.32604/icces.2021.08043

Abstract In modeling of material deformation responses, the physical phenomena such as stress singularity problems, strain localization and modeling of size effects cannot be properly captured by means of classical continuum mechanics. Therefore, various regularization techniques have been developed to overcome these problems. In the case of gradient approach the implicit gradient formulations are usually used when dealing with softening. Although the structural responses are mesh objective, they suffer from spurious damage growth. Therefore, a new formulation based on the strain gradient continuum theory, which includes both strain gradients and their stress conjugates, has been proposed.… More >

Roderick W. J. van Grootel, Allard T. van den Hoven, Dan Bowen, Tijmen Ris, Jolien W. Roos-Hesselink, Annemien E. van den Bosch^*

Congenital Heart Disease, Vol.16, No.3, pp. 221-232, 2021, DOI:10.32604/CHD.2021.013793 - 02 March 2021

Abstract Aims: To assess the prognostic value of left ventricular (LV) global longitudinal strain (GLS) and global longitudinal early diastolic strain rate (GLSre) with regard to cardiovascular events, as congenital aortic stenosis (AoS) is associated with significant mortality and morbidity but predictors for clinical outcome are scarce. Strain analysis provides a robust and reproducible method for early detection of LV dysfunction, which might be of prognostic value. Methods: This prospective study, included clinically stable patients with congenital AoS between 2011–2013. LV GLS and GLSre was performed in the apical 4, 3 and 2-chamber views using Tomtec software.… More >

Xiaorui Zhang^1,2,*, Hailun Wu¹, Wei Sun¹, Aiguo Song³, Sunil Kumar Jha⁴

Intelligent Automation & Soft Computing, Vol.27, No.3, pp. 873-889, 2021, DOI:10.32604/iasc.2021.013541 - 01 March 2021

Abstract Virtual surgery simulation is indispensable for virtual vascular interventional training system, which provides the doctor with visual scene between catheter and vascular. Soft tissue deformation, as the most significant part, determines the success or failure of the virtual surgery simulation. However, most soft tissue deformation model cannot simultaneously meet the requirement of high deformation accuracy and real-time interaction. To solve the challenge mentioned above, this paper proposes a fast and accurate vascular tissue simulation model based on point primitive method. Firstly, the proposed model simulates a deformation of the internal structure of the vascular tissue… More >

Mengcheng Sun^1,2, Weiya Xu^1,2,*, Huanling Wang^1,3, Qingxiang Meng^1,2, Long Yan^1,2, Wei-Chau Xie⁴

CMC-Computers, Materials & Continua, Vol.66, No.1, pp. 1057-1074, 2021, DOI:10.32604/cmc.2020.012537 - 30 October 2020

Abstract The narrowing deformation of reservoir valley during the initial operation period threatens the long-term safety of the dam, and an accurate prediction of valley deformation (VD) remains a challenging part of risk mitigation. In order to enhance the accuracy of VD prediction, a novel hybrid model combining Ensemble empirical mode decomposition based interval threshold denoising (EEMD-ITD), Differential evolutions—Shuffled frog leaping algorithm (DE-SFLA) and Least squares support vector machine (LSSVM) is proposed. The non-stationary VD series is firstly decomposed into several stationary subseries by EEMD; then, ITD is applied for redundant information denoising on special sub-series,… More >

Junfu Zhu¹, Qian Yin^1,2,*, Hongwen Jing¹, Xinshuai Shi¹, Minliang Chen^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.125, No.2, pp. 725-753, 2020, DOI:10.32604/cmes.2020.012648 - 12 October 2020

Abstract This study experimentally and numerically investigated the anchorage properties, bolt force evolution, deformation and stress fields of blocky rock mass with various dip angles of joint surfaces under an applied axial load. The results show that due to bolt reinforcement, the axial stress-strain curves of anchorage blocky rock mass show typical strain-hardening characteristics, and compared with models without anchorage, the peak strength and elastic modulus increase by 21.56% and 20.0%, respectively. With an increase in axial stress, the lateral strain continuously increases, and restriction effects of bolts reduce the overall deformation of model surfaces. The… More >

Xiaorui Zhang^1,2,*, Xuefeng Yu¹, Wei Sun², Aiguo Song³

CMES-Computer Modeling in Engineering & Sciences, Vol.124, No.3, pp. 1131-1147, 2020, DOI:10.32604/cmes.2020.09735 - 21 August 2020

Abstract In order to solve the problem of high computing cost and low simulation accuracy caused by discontinuity of incision in traditional meshless model, this paper proposes a soft tissue deformation model based on the Marquardt algorithm and enrichment function. The model is based on the element-free Galerkin method, in which Kelvin viscoelastic model and adjustment function are integrated. Marquardt algorithm is applied to fit the relation between force and displacement caused by surface deformation, and the enrichment function is applied to deal with the discontinuity in the meshless method. To verify the validity of the More >