Chengbao Hu^1,2,3, Shilin Gong^4,*, Bin Chen^1,2,3, Zhongling Zong⁴, Xingwang Bao⁵, Xiaojian Ru⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.1, pp. 997-1015, 2024, DOI:10.32604/cmes.2024.048640

Abstract Strain localization frequently occurs in cohesive materials with friction (e.g., composites, soils, rocks) and is widely recognized as a fundamental cause of progressive structural failure. Nonetheless, achieving high-fidelity simulation for this issue, particularly concerning strong discontinuities and tension-compression-shear behaviors within localized zones, remains significantly constrained. In response, this study introduces an integrated algorithm within the finite element framework, merging a coupled cohesive zone model (CZM) with the nonlinear augmented finite element method (N-AFEM). The coupled CZM comprehensively describes tension-compression and compression-shear failure behaviors in cohesive, frictional materials, while the N-AFEM allows nonlinear coupled intra-element discontinuities without necessitating extra nodes or… More >

Jai Hak Park^*

Digital Engineering and Digital Twin, Vol.2, pp. 79-101, 2024, DOI:10.32604/dedt.2024.047280

Abstract A finite element alternating method has been known as a very convenient and accurate method to solve two and three-dimensional crack problems. In this method, a general crack problem is solved by a superposition of two solutions. One is a finite element solution for a finite body without a crack, and the other is an analytical solution for a crack in an infinite body. Since a crack is not considered in a finite element model, generating a model is very simple. The method is especially very convenient for a fatigue crack growth simulation. Over the past 40 years, S. N.… More >

Fu Guan^1,*, Matthias Gass², Florian Berger², Heiko Schneider¹, Firat Duru^1,3, Thomas Wolber^1,3,*

Congenital Heart Disease, Vol.19, No.1, pp. 85-92, 2024, DOI:10.32604/chd.2024.047266

Abstract Aims: Although the application of ultrasound-guided vascular puncture and Z-stitch hemostasis to manage femoral access has been widely utilized, there is limited data on this combined application in adult congenital heart disease (ACHD) patients undergoing electrophysiological (EP) procedures. We sought to evaluate the safety and efficacy of ultrasound-guided puncture and postprocedural Z-stitch hemostasis for ACHD patients undergoing EP procedures. Methods and Results: The population of ACHD patients undergoing transfemoral EP procedures at the University of Zurich Heart Center between January 2019 and December 2022 was observed and analyzed. During the study period, femoral access (left/right, arterial/venous) was performed under real-time… More >

Jing Huang, Kapil Baheti, J. K. Chen^*, Yuwen Zhang

Frontiers in Heat and Mass Transfer, Vol.2, No.1, pp. 1-10, 2011, DOI:10.5098/hmt.v2.1.3005

Abstract An axisymmetric model for thermal transport in thin metal films irradiated by an ultrashort laser pulse was developed. The superheating phenomena including preheating, melting, vaporization and re-solidification were modeled and analyzed. Together with the energy balance, nucleation dynamics was employed iteratively to track the solid-liquid interface and the gas kinetics law was used iteratively to track the liquid-vapor interface. The numerical results showed that higher laser fluence and shorter pulse width lead to higher interfacial temperature, larger melting and ablation depths. A simplified 1-D model could overestimate temperature response and ablation depth due to the omission of radial heat conduction. More >

Yunpeng Ren, J. K. Chen^*, Yuwen Zhang

Frontiers in Heat and Mass Transfer, Vol.3, No.2, pp. 1-7, 2012, DOI:10.5098/hmt.v3.2.3001

Abstract Heat transfer in a copper film irradiated by a femtosecond (fs) laser pulse train and by an integrated dual laser beam of a nanosecond pulse with a fspulse train was studied using the semi-classical two-temperature model. The critical point model with three Lorentzian terms was employed to characterize transient optical properties for the laser energy deposition. The effects of pulse number and separation time on the thermal response were investigated. The results showed that with the same total energy in a fs-pulse train, more pulses for shorter separation time, e.g., 1 ps, and fewer pulses for longer separation time, e.g.,… More >

Mohammad Javad SheikhMozafari^*

Sound & Vibration, Vol.58, pp. 81-100, 2024, DOI:10.32604/sv.2024.048897

Abstract Mitigating low-frequency noise poses a significant challenge for acoustic engineers, due to their long wavelength, with conventional porous sound absorbers showing limitations in attenuating such noise. An effective strategy involves combining porous materials with micro-perforated plates (MPP) to address this issue. Given the significant impact of structural variables like panel thickness, hole diameter, and air gap on the acoustic characteristics of MPP, achieving the optimal condition demands numerous sample iterations. The impedance tube’s considerable expense for sound absorption measurement and the substantial cost involved in fabricating each sample using a 3D printer underscore the advantage of utilizing simulation methods to… More > Graphic Abstract

Peilei Yan^1,2,*, Endong Guo^1,2, Houli Wu^1,2, Liangchao Zhang^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.2, pp. 1655-1678, 2024, DOI:10.32604/cmes.2023.044760

Abstract A coupled numerical calculation method combining smooth particle hydrodynamics (SPH) and the finite element method (FEM) was implemented to investigate the seismic response of horizontal storage tanks. A numerical model of a horizontal storage tank featuring a free liquid surface under seismic action was constructed using the SPH–FEM coupling method. The stored liquid was discretized using SPH particles, while the tank and supports were discretized using the FEM. The interaction between the stored liquid and the tank was simulated by using the meshless particle contact method. Then, the numerical simulation results were compared and analyzed against seismic simulation shaking table… More >

Afraz Hussain Majeed¹, Rashid Mahmood², Sayed M. Eldin³, Imran Saddique^4,5,*, S. Saleem⁶, Muhammad Jawad⁷

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.2, pp. 1505-1519, 2024, DOI:10.32604/cmes.2023.030255

Abstract This study explains the entropy process of natural convective heating in the nanofluid-saturated cavity in a heated fin and magnetic field. The temperature is constant on the Y-shaped fin, insulating the top wall while the remaining walls remain cold. All walls are subject to impermeability and non-slip conditions. The mathematical modeling of the problem is demonstrated by the continuity, momentum, and energy equations incorporating the inclined magnetic field. For elucidating the flow characteristics Finite Element Method (FEM) is implemented using stable FE pair. A hybrid fine mesh is used for discretizing the domain. Velocity and thermal plots concerning parameters are… More >

Dave Martin^a,b,† , Hicham Chaouki^a,b, Jean-Loup Robert^a, Donald Ziegler^c, Mario Fafard^a,b

Frontiers in Heat and Mass Transfer, Vol.7, pp. 1-9, 2016, DOI:10.5098/hmt.7.31

Abstract The two dimensional phase change problem was solved using the extended finite element method with a Lagrange formulation to apply the interface boundary condition. The Lagrange multiplier space is identical to the solution space and does not require stabilization. The solid-liquid interface velocity is determined by the jump in heat flux across the i nterface. Two methods to calculate the jump are used and c ompared. The first is based on an averaged temperature gradient near the interface. The second uses the Lagrange multiplier values to evaluate the jump. The Lagrange multiplier based approach was shown to be more robust… More >

Dave Martin^a,b,† , Hicham Chaouki^a,b, Jean-Loup Robert^a, Donald Ziegler^c, Mario Fafard^a,b

Frontiers in Heat and Mass Transfer, Vol.7, pp. 1-11, 2016, DOI:10.5098/hmt.7.40

Abstract A two phase model for two-dimensional solidification problems with variable densities was developed by coupling the Stefan problem with the Stokes problem and applying a mass conserving velocity condition on the phase change interface. The extended finite element method (XFEM) was used to capture the strong discontinuity of the velocity and pressure as well as the jump in heat flux at the i nterface. The melting temperature and velocity condition were imposed on the interface using a Lagrange multiplier and the penalization method, respectively. The resulting formulations were then coupled using a fixed point iteration a lgorithm. Three examples were… More >