The fracture properties of a high-strength steel with a body-centered cubic (bcc) crystal structure have been characterized at –196°C by performing tensile tests with different specimen geometries, three-point bending tests using Charpy specimens, and fracture mechanics tests, covering a broad range of stress states under quasi-static conditions. Both strength and ductility of the bcc steel are significantly

Size effects (SEs) impede the mass production of high-performance miniaturised components via micro-forming. Although many studies have examined SEs from multiple aspects, such as flow stress, deformation, and ductile fracture, the SE transitions characterised by the significant changes of these phenomena across the micro- and macroscale remain ambiguous. These SE transitions must be fully and deeply

The available numerical methods for performing finite element unit cell calculations under stress states evolving in a predefined manner restrict the most general stress state to a single shear stress component superimposed on three normal stress components. The present study builds on and extends state of the art such that the behavior of a unit cell under the most complex stress states, comprising

Glassy polymers exhibit a strong thermomechanical coupling when subjected to mechanical loading. A homogeneous strain distribution can be achieved in uniaxial compression conditions. However, a clear temperature increase is observed when the loading rate is relatively high, which further results in a decrease in stress due to thermal softening. In tensile tests, necking instability can easily occur

A new model of gradient crystal plasticity is developed in which the incompatibility of plastic deformation field is simultaneously included in two different ways. The first one is well known and incorporates the gradient effect of accumulated rotation of the crystallographic lattice on the kinematic hardening in the Cosserat crystal plasticity model. The second way incorporates the effect of the current

A combined experimental and strain gradient crystal plasticity framework is presented for studying the development of orientation and misorientation gradients at the grain boundaries during plastic deformation. The regions in the vicinity of prior-deformation grain boundaries experience localized plastic deformation and are referred to as Near Boundary Gradient Zones (NBGZs). Deformed microstructures

We compare two machine-learning-based approaches, artificial neural network (ANN) and micromechanical model with automatic Bayesian identification of the model parameters, in application to mimicking the deformation behavior of nanoporous aluminum extracted from molecular dynamics (MD) simulations. Reference data are generated by means of MD simulation of both hydrostatic and uniaxial deformation with

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 with the rotation angle θ from 0° to 90° were studied

Titanium is promising for manufacturing high-performance components in aerospace, marine, energy and healthcare. Whether the forming potential of alpha titanium can be excavated under cryogenic and warm working conditions and how the anisotropic plasticity and fracture evolve over a wide temperature range are the premise and basis for accurate control of inhomogeneous deformation of the material and

Quenching and partitioning (Q&P) steels, as one of the third-generation advanced high strength steels, exhibit complex anisotropic hardening behavior under biaxial non-proportional loadings. In this study, a wide range of strain path changes (SPCs) defined as an angle (χ) between stress deviators before and after the SPC is experimentally applied to characterize the anisotropic hardening of a Q&P steel

In this study, a novel approach to modeling the ultrasonic softening effect during metal plasticity is developed, where the slip systems experience differential softening depending on their orientation relative to the ultrasonic direction. The directional softening model was implemented within a Visco-Plastic Self-Consistent (VPSC) model, where the material and ultrasonic softening parameters are calibrated

In this paper, a new constitutive model for plastic behavior of the metastable austenitic stainless steels at cryogenic temperatures is presented. The constitutive model is a phenomenological hyperelastic-based large deformation model developed in the framework of continuum damage mechanics considering the dissipative phenomena of strain-induced phase transformation and damage growth during plastic

Digital Rock Physics has reached a level of maturity on the characterisation of primary properties that depend on the microstructure – such as porosity, permeability or elastic moduli – by numerically solving field equations on μCT scan images of rock. After small deformations or at depth though, most rocks eventually reach their limit of elasticity and the complementary plastic properties are needed

The interaction phenomenon between a propagating crack impinging an interface is studied with a phase-field approach in combination with a cohesive surface model. The phase-field technique simulates the crack propagation across the medium, and the cohesive surface model simulates the degradation process of the adhesive interface. The main assessed mechanisms of this interaction are deflection of the

The present study addresses the evolution of microstructural and crystallographic texture in room-temperature-rolled (RTR) and cryogenic-rolled (CR) electrolytic tough-pitch (ETP) copper. Copper specimens were subjected to 20, 40, 60, and 80% reductions via RTR and CR processing. The microstructure evolution of the severely deformed RTR and CR specimens revealed deformed and recrystallized grains.

The selective laser melted (SLM) 316L stainless steel (316L SS) has shown superior tensile ductility and doubled yield strength compared to its wrought counterpart. The significantly improved yield strength has been attributed to the unique cellular substructures featured by Cr/Mo-segregation and trapped dislocations. The excellent ductility of SLMed 316L SS has been mainly understood from the pronounced

Deformation twinning and detwinning in extruded Mg-4Al were investigated using in-situ SEM-DIC experiments and crystal plasticity finite element (CPFE) simulation. In this study, the in-situ SEM-DIC method was used to provide a unique set of data including twin/detwin characteristics and twin area fraction in addition to strain maps. A statistical analysis of the activation of twin variants and twin

A fast Fourier transform (FFT) based modular solver for crystal plasticity is presented in this work. In the framework, balance of momentum is solved in a global iterative loop and single crystal plasticity is solved in an inner loop. For the latter, a fully implicit time integration scheme is used in which the correct solution is found using a residual established based on plastic velocity gradient

We present a computational algorithm for solving the recently developed finite-deformation continuum dislocation dynamics theory of mesoscale plastic deformation of single crystals (Starkey et al., 2020). This CDD theory is based on a vector density representation of dislocations governed by curl-type transport-reaction equations subjected to the divergence-free constraint of the appropriate dislocation

The strain rate sensitivity (SRS) of binary Mg–Gd and Mg–Y alloys and the effect of solute on the rate-controlling mechanisms have been studied by analyzing rate changes during tension and compression tests at 78K and 298K. The steady-state SRS evaluated from the slope of Haasen plots at 78K increases with the solute concentration. The reverse behavior is observed at 298K, and the concentrated alloys

In this paper, a series of strain-controlled fatigue and creep–fatigue tests under proportional/non-proportional loadings were performed for type 304 stainless steel at 873 K. Then, post-test metallographic observations were performed through the electron back scattered diffraction (EBSD) and transmission electron microscope (TEM) combinative characterizations. In this aspect, the wavy slip dominated

Large-scale molecular dynamics simulations are conducted on single crystal copper along eight representative orientations to investigate dislocation-dominated void nucleation during shock loading and spall failure, including mechanisms and anisotropy. Spall strength estimated from free surface velocity decreases in the order of group I ([001]), group IV ([012] and [011]), group III ([122] and [123])

Ultrathin sheet steels used in the global packaging industry for lightweight packaging applications have been achieved by an extra cold processing (double reduction) to increase yield stress, but usually at a severe loss of uniform elongation and formability. From an industrial point of view, achieving the synergy of strength and uniform tensile ductility in ultrathin sheets is difficult, owing to

Tungsten (W) is a promising candidate material for future fusion reactors. The shock waves generated under high-energy neutron radiation can lead to the formation of prismatic interstitial dislocation loops (PIDLs). To understand the details of the mechanisms, the interaction between the shock waves and PIDL with Burgers vector of 1/2<111> was studied by using nonequilibrium molecular dynamics (NEMD)

The creep-fatigue interaction has been recognized as the main failure mode of most structural components operating in the high-temperature regime. The cyclic life (Nf) usually decreases continuously with the dwell time in their interactions. However, Nf shows an abnormal change, i.e. keeps constant or slightly increases/decreases, in the present studied Nickel-based superalloy, DZ445. This means that

In newly developed hydrogel-based devices, hydrogels are commonly used in load-bearing components subjected to prolonged cyclic deformations. The anti-fatigue capability of hydrogels is crucial for extending the service life of the devices. While recent developments in the synthesis and characterisation of tough hydrogels have facilitated continuous improvements of the fatigue resistance, the underlying

Even though crystal plasticity models have been available for decades, the quantification of material parameters is still a matter of debate. Polycrystalline experimental results can normally be reproduced by multiple sets of parameters, raising concerns about the best parameterization to predict the grain-level response. This work presents a novel physics-based crystal plasticity model based on mesoscale

The mechanical behavior and microstructure at fracture of a rolled AZ31B magnesium alloy were experimentally investigated using tubular specimens subjected to combined axial-torsion loading with different ratios of the axial and shear stress components. The stress state influences the stress-strain responses. The equivalent stress-equivalent plastic strain curves under tension-torsion loading show

This paper presents hexah, a framework based on the homogeneous anisotropic hardening (HAH) model. It aims at recreating the effects of arbitrary strain path changes over the plastic behavior of metals. Its core relies on the concept of microstructure deviator, a tensor representing one set of active slip systems. The present theory makes use of an arbitrary number of microstructure deviators spawned

We develop a new finite deformation constitutive model for metallic glass within the framework of irreversible nonequilibrium thermodynamics. To consider the intrinsically out-of-equilibrium characteristics of metallic glass, its total internal energy is divided into two weakly coupled configurational and kinetic subsystems, and configurational temperature coupling with configurational degrees of freedom

While multiple plastic deformation mechanisms at room temperature in the CrMnFeCoNi high-entropy alloy (HEA) have been revealed experimentally, the qualitative and/or quantitative effects of the microstructural evolution on crack growth are studied rarely. In this work, the effects of crack bridging, crack-tip dislocation emission, and crack deflection on crack growth are modeled and analyzed. The

Accurate material behaviour and its response to loading are needed for a reliable calibration of ductile failure criteria. Non-quadratic yield functions are often necessary for such a description. Nevertheless, it leads to the prediction of stress states that are inconsistent with the expected behaviour and deformations that are in contradiction with the experiments when the associated flow rule is

Strain path change is common phenomenon during industrial sheet metal forming processes. These strain paths can be proportional and non-proportional in nature. To enable strain path change in a single experiment is key challenge faced by many researchers. To predict deformation behavior accurately during such strain paths, it is required to represent initial yielding, the evolution of subsequent yield

The present study investigated the size effect on the formability of ultra-thin metallic bipolar plate for proton exchange membrane (PEM) fuel cell by crystal plasticity finite element method (CPFEM) in conjunction with the Marciniak-Kuczynski (MK) model. Mechanical behavior and crystallographic texture of a 0.08 mm-thick ferritic stainless steel (FSS) sheet were characterized by uniaxial tensile test

For most metallic materials, surface hardening via modifying the near-surface microstructure is an effective method for improving mechanical properties. Among these processes, laser shock peening (LSP), which is versatile and nondestructive to the fabricated product shape, has received much attention. The present work has shown that the mechanical properties of CrFeCoNiMn0.75Cu0.25 high entropy alloy

The influence of α-Mg/LPSO (Long-Period Stacking Ordered) phase interfaces on the flow stress of as-cast Mg-Zn-Y alloys was experimentally and numerically evaluated by compressive loading samples with different volume fractions of LPSO phase. The experimental results showed that the flow stresses of Mg-Zn-Y alloys with LPSO volume fractions ranging from 40 to 85% are clearly higher than those of single

Tungsten is used for vital applications in nuclear industry, particularly in experimental fusion reactors like ITER. Experimental evaluation of the irradiation-induced hardening is usually carried out by indentation tests. However, accurate prediction of irradiation hardening by indentation simulations faces two challenges: (1) compression data of single-crystal tungsten for indentation model calibration

Within multiscale modeling strategies for composite materials, standard Hill averaging is widely used for homogenization of repeating unit cells (RUCs). However, Hill’s homogenization approach reaches its limitations at the presence of strain softening, because in the standard averaging sense the representativeness of the considered micro-scale volume is lost. Hence, in order to overcome these limitations

The mechanical responses of hexagonal close-packed (HCP) materials are highly anisotropic, as well as strain rate and temperature-dependent, because of inherently asymmetric slip and twinning in constituent crystalline grains. How slip and twinning are affected by strain rate/temperature and how they alter the deformation response of HCP materials are still not well understood. To provide greater insights

The properties of individual phases and complex interactions of phases that affect mechanical behavior of metastable lamellar and Widmanstaetten morphologies of α+β Titanium alloys has long eluded quantitative assessment. As a result, the uncertainty of models for these complex multiphase morphologies is high, despite their importance in practical high-value applications. In this work, we present a

The detailed contribution of microstructural-level phenomena, such as dislocation structure development and annihilation, as well as inter-granular and intra-granular backstress fields, to reverse loading behavior in metal alloys remains an area of active research and debate. The ability to predict unloading nonlinearities, the Bauschinger effect (BE), and changes in hardening rates during reverse

In this study, a thermodynamically consistent damage model is presented to predict failure in glassy polymers. This model is based on the Eindhoven Glassy Polymer (EGP) multimode model, and it considers the effects of plastic deformation and hydrostatic stress on damage evolution. The model is implemented as an ABAQUS user material (UMAT) subroutine. Three experiments are simulated to show the model’s

Mineral grains and porosity are two common properties of geomaterials. This study focuses on establishing a macroscopic yield criterion for geomaterials having pores and mineral grains at the mesoscale which is embedded in a porous matrix. At the microscale, the solid phase is pressure-sensitive and obeys to the Drucker–Prager criterion which considers the asymmetric property between tension and compression