Haidong Fan

• PhD
• Professor (Full) at Sichuan University

Through-silicon via (TSV) is an important technique in three-dimension integration. The mechanical performance of TSV-Cu is critical to the electrical performance and signal transmission. In this work, the deformation of single-crystalline TSV-Cu during annealing process was studied using molecular dynamics method. The protrusion morphology and pro...

The pulse-based rapid domain structure switching method in ferroelectric memristors has stability and other issues, limiting its applications. In this study, we perform atomic simulations to investigate the polarization domain switching behavior of ferroelectric materials under non-pulse torsional loading. During torsion, uniformly distributed spon...

In this work, the deformation modes in TiZrHf MEA (medium entropy alloy) under tensile loading and compressive loading were investigated by molecular dynamics simulations. The orientation effect on the mechanical response was revealed by changing the orientation angle θ between c-axis and loading direction. Under tensile loading, the deformation mo...

The total internal reflection (TIR) behavior of interface shear waves is crucial for ensuring the reliability of dielectric elastomer (DE) devices. However, due to the complex force-electric coupling and large deformation of DEs, the TIR behavior of shear waves in heterogeneous force-electric interface models is still unclear. This study modeled an...

In polycrystalline magnesium (Mg) and Mg alloys, as the grain size decreases, the grain boundary (GB) mediated plasticity including GB sliding and GB migration becomes the dominant deformation mechanism. In this study, the motion of \([1\bar 100]\) symmetric tilt GBs in Mg bicrystals is investigated using molecular dynamics (MD) simulations. The ef...

Two-dimensional (2D) multiferroic materials are recognized as promising candidates for next-generation nanodevices due to their tunable magnetoelectric coupling and distinctive physical phenomena. In this study, we proposed a novel 2D multiferroic van der Waals heterostructure (vdWH) by stacking atomic layers of ferroelectric In 2 Se 3 and ferromag...

Surface effects usually remarkably affect the mechanical response of ultra-thin micro-/nano-structures. However, the mechanisms of surface effects on the fracture characteristics of ultra-thin films are still not fully understood. To this end, this paper develops a modeling framework to investigate the fracture of ultra-thin films at microscales or...

Single-phase concentrated solid solution alloys (SP-CSAs), including high-entropy alloys, have received extensive attention due to their excellent irradiation resistance. In this work, displacement cascade simulations are conducted using the molecular dynamics method to study the evolution of defects in Ni-based SP-CSAs. Compared with pure Ni, the...

Most of quasi-crystals are brittle at room temperature due to their specific cluster structures. Phase-field fracture models have demonstrated a powerful ability to predict brittle crack evolution. This paper develops a phase-field framework for modeling macroscopic brittle fracture in quasi-crystal solids. The kind of quasi-crystals is not preset...

Molecular dynamics simulation was applied to investigate the interaction between precipitate and \(\left\{ {10\overline{1}2} \right\}\) twin in Mg-Al alloy in this work. Three sets of simulation including twin nucleation, propagation and growth affected by precipitate were performed. The results show the introduction of precipitate has little effec...

Grain boundaries (GBs) are one of the main factors influencing the polar domain evolution of polycrystalline ferroelectrics. However, domain switching from GBs to grains remains an unsolved aspect. Previous microscopic GB assumptions hinder such theoretical investigations, assuming that the structure and properties of GB are independent of the miso...

The shear failure of ferroelectric material is hard to investigate because of the electromechanical properties of the material and its high speed at the nanoscale. The brittleness of the material also limits the potential applications of these materials in ferroelectric devices. In this work, we use atomic simulations to investigate simultaneously...

Plasticity modelling has long relied on phenomenological models based on ad-hoc assumption of constitutive relations, which are then fitted to limited data. Other work is based on the consideration of physical mechanisms which seek to establish a physical foundation of the observed plastic deformation behavior through identification of isolated def...

Grain boundaries (GBs) are transitional, defective, and anisotropic interfaces between adjacent grains with different orientations. However, most models assume that the GB is an isotropic dielectric determined by itself and lacks formation information; these assumptions hinder the theoretical investigation of the effect GBs have on polycrystalline...

In polycrystalline materials, grain boundaries (GBs) play an important role in resisting crack growth. In this study, the interaction of a crack on basal plane with GBs in magnesium was investigated by molecular statics simulations. Three types of GBs with different mis-orientation angles were considered, i.e., [21¯1¯0] asymmetric tilt GB, (011¯0)...

Zirconium alloys were widely used as fuel cladding in nuclear reactors. Stacking fault pyramid (SFP) is an irradiation-induced defect in zirconium. In this work, the formation process of SFP from a hexagonal vacancy plate on basal plane is studied by molecular dynamics (MD) simulations. The results show that, during the SFP formation from a basal v...

The generation of topological domain structures can significantly influence the behaviors of ferroelectric materials, and, however, strategies and perspectives for treating and analyzing them are still lacking. Inspired by the fluid lines and vorticity in hydromechanics, a characterization method of polarization lines and polarization vorticity is...

Domain pattern is the carrier of electromechanical property. A novel domain pattern will open a gate for ferroelectric nanodevice. A distinctive topological domain pattern termed as hierarchical vortex (Hvo) has been found in polycrystalline ferroelectric based on the first-principles-based atomistic method. The Hvo pattern displays a unique struct...

Plasticity modelling has long been based on phenomenological models based on ad-hoc assuption of constitutive relations, which are then fitted to limited data. Other work is based on the consideration of physical mechanisms which seek to establish a physical foundation of the observed plastic deformation behavior through identification of isolated...

Grain boundary (GB) is an important microstructure and plays a vital role in the mechanical properties of polycrystalline materials by GB migration and sliding. In this work, molecular dynamic (MD) simulations were performed to investigate the migration mechanisms of [12¯10] symmetric tilt grain boundaries (STGBs) in magnesium. A total of 15 STGBs...

Precipitates play an important role in the evolution of irradiation-induced defects and mechanical property of irradiated metals. In this work, the effects of a Zr2Cu precipitate on the production and subsequent evolution of cascade-induced point defects (vacancies and interstitials) in ZrCu alloy were investigated by molecular dynamics simulations...

The stress gradient associated with the notch geometry was integrated into the critical distance estimate procedure and formed the Stress Gradient Method (SGM) proposed in this study. The critical distance was discovered to be highly related to the product of the fatigue life and the stress gradient. The fatigue life of varied notched specimens was...

This paper develops the adhesive contact theory for a one-dimensional hexagonal quasicrystal half-space punched by a spherical indenter on the basis of the classical adhesive contact models involving the Johnson–Kendall–Roberts (JKR) model, the Maugis–Dugdale (MD) model and the Derjaguin–Muller–Toporov (DMT) model. By using the superposition princi...

Objective : Sauna bathing (SB) is an important strategy in cardiovascular protection, but there is no mathematical explanation for the reallocation of blood circulation during heat-induced superficial vasodilation. We sought to reveal such reallocation via a simulated hemodynamic model. Methods : A closed-loop cardiovascular model with a series of...

A novel dislocation mechanism to interpret the Bauschinger effect in polycrystalline metals is proposed namely dislocation pile-up polarization. We show that the variability of GB resistance to dislocation transmission, an inherent characteristic in polycrystalline metals, can break the symmetry of double dislocation pile-ups during plastic deforma...

In this paper, molecular dynamics simulations are performed to investigate the decomposition of \(\langle c+a \rangle \) dislocations on both pyramidal-I and pyramidal-II planes. The pyramidal-I dislocations are decomposed into \(\langle c \rangle \) and \(\langle a \rangle \) dislocations under shear stress at 0–400 K, which all reside on the basa...

Duo to the low thermal neutron capture cross-section and high corrosion resistance to water and steam at high temperatures, zirconium alloys were used as fuel cladding in light water reactors. In this work, the effects of vacancies on {101¯2} twin boundary (TB) migration were studied by molecular dynamics (MD) simulations in zirconium at different...

In this work, we performed molecular dynamics (MD) simulations on the interactions between a basal edge < a > dislocation and point defects including vacancies and self-interstitial atoms in magnesium. Simulation results suggest that both self-interstitial atoms and vacancies have a blocking effect on dislocation motion, but the blocking effect of...

Due to the broken of inversion and mirror symmetry, Janus structures are believed to have abundant properties and can be applied in two-dimensional (2D) materials, but the research of 2D Janus materials is insufficient. In this work, Janus materials ZnXY2 (X=Ge, Sn, Si and Y=S, Se, Te) monolayers are designed referring to group-III monochalcogenide...

In this work, molecular dynamics simulations were employed to investigate the interaction between a {101¯2} twin boundary (TB) and irradiation-induced dislocation loops in magnesium at room temperature. According to the geometry of the Burgers vectors with respect to TB, three sets of partial Burgers vectors can be identified, i.e. 1/6[202¯3]+1/6[2...

As an important micro-structure, grain boundary plays a significant role in the micro-structure evolution and mechanical property of metallic materials. In this study, comprehensive molecular dynamics simulations were performed to investigate the propagation mechanisms of intergranular cracks along [11-00] symmetric tilt grain boundaries in magnesi...

Recently, the effectiveness of internal iliac artery balloon occlusion (IIABO) for treating postpartum hemorrhage caused by pernicious placenta previa (PPP) has been questioned. We conducted a retrospective analysis and hemodynamic simulation to assess the IIABO’s effectiveness. The retrospective analysis involved 480 patients with PPP, among which...

Magnesium is a lightweight structural metal and has important applications. However, the dislocation plasticity of magnesium was not well studied, especially the pyramidal dislocations. In this paper, molecular dynamics (MD) simulations were performed to systematically investigate the dislocation interactions, i.e. between <c + a> dislocations, bet...

Objective The focus of this study is to model the cardiovascular system (CS) involving regional skin blood flow (SBF) to gain new insights into the skin-CS relationship. Methods A lumped parameter model with a series of electrical components was developed to model the CS involving SBF. Four parts were considered: the heart, arterial circulation, m...

The interactions between a plate-like precipitate and two twin boundaries (TBs) ( { 10 ¯1 2 } , { 11 ¯2 1 } ) in magnesium alloys are studied using molecular dynamics (MD) simulations. The precipitate is not sheared by { 10 ¯1 2 } TB, but sheared by { 11 ¯2 1 } TB. Shearing on the (110) plane is the predominant deformation mode in the sheared preci...

The stress concentration effect reduces fatigue resistance of notched geometries. The stress gradient strongly related to stress concentration plays a significant role in material strength assessment. This article attempts to propose a new fatigue life estimation method, named volume stress gradient method (VSGM) by introducing the stress gradient...

Vacancy defects are inevitable when synthesizing two-dimensional (2D) materials, and vacancy defects greatly affect the physical properties, such as magnetism and electronic properties. Currently, sufficient information is not available on whether and how the interaction of vacancy defects affects material properties and how to control these defect...

Dislocation glide is a general deformation mode, governing the strength of metals. Via discrete dislocation dynamics and molecular dynamics simulations, we investigate the strain rate and dislocation density dependence of the strength of bulk copper and aluminum single crystals. An analytical relationship between material strength, dislocation dens...

Dislocation glide is a general deformation mode, governing the strength of metals. Via discrete dislocation dynamics and molecular dynamics simulations, we investigate the strain rate and dislocation density dependence of the strength of bulk copper and aluminum single crystals. An analytical relationship between material strength, dislocation dens...

The interactions between a {10-12} twin boundary and point defects including vacancies and self-interstitial atoms in magnesium were investigated by molecular dynamics simulations at low temperature. The simulation results suggest that vacancies have a softening effect on TB migration, while interstitials lead to a hardening effect. During the int...

As the lightest structural metal, magnesiumMagnesium (Mg) and its alloys have an important application on aircrafts, and would work under an irradiation condition, i.e. in outer space. So it is significant to study the microstructure and mechanical property of irradiated magnesiumMagnesium. In this work, we performed molecular dynamics simulationsM...

Molecular dynamics simulations were performed to investigate the cyclic deformation of magnesium single crystalline nano-pillars in the first three cycles. To study the tension–compression asymmetry, two symmetric uniaxial cyclic loading paths (applied strain amplitude = 10%) were employed, i.e., a triangle wave loading path started by tension and...

Two-dimensional (2D) van der Waals heterostructures (vdWHs) have attracted significant attention due to their potential applications in nanoscale electronic devices. Based on the first-principles calculations, we design the SnSe/SnTe and SnSe/SnTe/SnSe vdWHs with dynamical stability and thermal stability and investigate their mechanical and electro...

Ferroelectric domain structures have attracted much attention due to their potential applications in storage. In this paper, the molecular dynamics method based on shell model is employed to simulate the uniaxial tensile strain applied to the BaTiO3 thin film, and the effect of strain on the polarization domain structure of BaTiO3 thin film is disc...

The corresponding author was incorrectly designated in the original article

We predict a new family of two-dimensional (2D) rare earth monochalcogenide materials MX (M = Sc, Y; X = S, Se, Te). Based on first-principles calculations, we confirm their stability and systematically investigate their mechanical properties. We find that these materials are metallic and interestingly, they possess nodal lines in the low-energy ba...

This paper develops a closed-form analytical solution for the problem of an infinite transversely isotropic thermoporoelastic rock weakened by an elliptic crack lying in the transverse plane. The crack is symmetrically subjected to three pairs of uniform generalized loads, i.e., mechanical pressure, pore pressure and temperature increment, on the u...

In this work, the dynamical mechanical properties and dislocation evolution of copper single crystals were studied using the discrete dislocation dynamics (DDD) method coupled with dynamical finite element method. The infuence of strain rate, dislocation density and crystalline orientation were investigated. Strong strain rate effect was observed i...

Dislocation slip is a general deformation mode and governs the strength of metals. Via discrete dislocation dynamics and molecular dynamics simulations, we investigate the strain rate and dislocation density dependence of the strength of bulk copper single crystals using 192 simulations spanning over 10 orders of magnitude in strain rate and 9 orde...

Deformation twinning is a common plastic deformation mode in polycrystalline magnesium (Mg), so the interaction between twin boundary (TB) and grain boundary (GB) plays an important role in the improvement of material strength and ductility. In this work, molecular dynamics (MD) method was employed to study the interaction between TB and GB. Four G...

The elastic properties, core structures, critical resolved shear stresses (CRSSs), and mobility of 1/2〈110〉 edge dislocations in NiCoFe and NiCoFeCu equiatomic solid-solution alloys was predicted using molecular statics and dynamics simulations using two different embedded atom method (EAM) potentials. In particular, the Johnshon–Zhou potential is...

This article analytically investigates the temperature influence on the performance of laterally constrained dielectric elastomer actuators. The effects of both temperature and stretches on the permittivity are taken into consideration. The governing equations of state are established by modeling the actuator as a thermodynamic system of three degr...

Twin boundaries (TBs) constitute a special type of symmetric grain boundary (GB). TBs influence plastic deformation in a complex manner. They not only act as dislocation obstacles but can also accommodate twinning dislocations (TDs) whose motion enables twin boundary migration as an alternative deformation mechanism. Exploiting this dual effect off...

Twin boundaries (TBs) constitute a special type of symmetric grain boundary (GB). TBs influence plastic deformation in a complex manner. They not only act as dislocation obstacles but can also accommodate twinning dislocations (TDs) whose motion enables twin boundary migration as an alternative deformation mechanism. Exploiting this dual effect off...

In this study, we use discrete dislocation dynamics simulation to investigate the effect of heterogeneous dislocation density on the transition between quasi-elastic deformation and plastic flow in face-centered cubic single crystals. By analyzing the stress-strain curves of samples with an initial, axial dislocation density gradient, we arrive at...

In this study, we use discrete dislocation dynamics simulation to investigate the effect of heterogeneous dislocation density on the transition between quasi-elastic deformation and plastic flow in face-centered cubic single crystals. By analyzing the stress–strain curves of samples with an initial, axial dislocation density gradient, we arrive at...

Two-dimensional (2D) group IV monochalcogenides have attracted extensively attention due to their specific electronic properties and promising applications. SnTe monolayer is an exemplar in two-dimensional group IV monochalcogenides and shows robust ferroelectric properties at room-temperature. Using first principles calculation based on the densit...

Twin boundaryTwin boundary (TB) as a perfectly symmetric grain boundary has received lots of attention for the positive effects on material strengthStrength and ductility. A bicrystal containing a vertical TB was introduced in discrete dislocation dynamicsDislocation dynamics (DDD) method to study the effect of TB on the mechanical propertyMechanic...

Nanoindentation is a convenient method to investigate the mechanical properties of materials on small scales by utilizing low loads and small indentation depths. However, the effect of grain boundaries (GB) on the nanoindentation response remains unclear and needs to be studied by investigating in detail the interactions between dislocations and GB...

In this study, we use discrete dislocation dynamics (DDD) simulation to investigate the effect of heterogeneous dislocation density on the transition between quasi-elastic deformation and plastic flow in face-centered cubic single crystals. By analyzing the stress-strain curves of samples with an initial, axial dislocation density gradient, we arri...

In magnesium alloys, the precipitate orientation was observed to play an important role in the precipitation hardening effects. In this work, molecular dynamics (MD) simulations were employed to study the interaction of {10–12} extension twin boundaries (TBs) with plate-like Mg17Al12 precipitates having different orientation angles with respect to...

Domain wall (DW) plays an important role in the domain evolution. The anti-vortex could be a special domain structure of the mixed DWs, i.e. the Ising wall and the Mixed Ising-Neel wall. The anti-vortex domain in polycrystalline ferroelectric has been investigated by a modified first-principles-based atomistic method incorporating the anisotropic s...

Whereas conventional precipitation hardening is well-known to feature a single hardness peak, recently, double-peak precipitation hardening was observed, where the first peak hardness is higher than the second conventional one, thus offering a new approach to strengthen materials. Yet, classical precipitation strengthening models fail to predict su...