Deformation Processes In Materials Research Articles

A hybrid thermo-mechanical phase-field model for anisotropic brittle fracture

The phase-field modeling approach is integrated with the isogeometric-meshfree approach to investigate the coupled thermo-mechanical fracture behaviors of composite materials, accounting for material anisotropy. The present approach is formulated within a thermodynamic framework, exploring the effects of both thermal and mechanical factors on crack evolution. The crack driving force in composites is determined by the collective contributions from both fibers and the matrix. Moreover, a hybrid computational framework, enhanced with an adaptive mesh refinement technique, is proposed for the efficient implementation of thermo-mechanical fracture. Finally, simulations of the thermal deformation and fracture processes in both homogeneous and composite materials are implemented to verify the present approach. The impact of the weak material anisotropy, such as anisotropic thermal conductivity and material strength, along with the strong anisotropy coefficient on fracture patterns in orthotropic composites is also investigated. The simulation results demonstrate that the developed approach can predict complex failure patterns in composites under thermo-mechanical loading, thus offering insights for the design of composites.

In-situ characterization of thermo-mechanical deformation fields based on DIC during orthogonal cutting of Ti6Al4V

Cutting phenomena containing abundant kinematic and thermo-mechanical information during the cutting process provide direct evidence for investigating machining mechanisms. In-situ digital image correlation (DIC) measurements are important methods for obtaining dynamic data such as strain and strain rate during the material deformation process. However, the secondary development of those deformation data is limited. The deformation information obtained by DIC is also limited to understanding complex thermo-mechanical deformation. In this study, an in-situ imaging system was developed to simultaneously acquire gray and infrared radiation (IR) images within the same deformation area during orthogonal cutting of Ti6Al4V. The deformation evolution and thermal history can be obtained simultaneously. In addition, a postprocessing methodology based on the DIC was proposed to derive thermo-mechanical information. Based on the postprocessing methodology, the stress fields were determined by the constitutive equation combined with the strain, strain rate, and temperature data. The stress propagation path during the formation of the chip segment was determined. Finally, the strain energy fields were derived to assess the potential energy of plastic deformation with the generation of the adiabatic shear band. The dependency between the machining phenomena and the cutting parameters was investigated. This work provides a novel understanding of the thermo-mechanical coupling behavior during the generation progress of serrated chips. The nature of the formation mechanisms and the deformation process involved for serrated chips are closely revealed.

Mechanochromic polymer blends made with an excimer-forming telechelic sensor molecule.

The ability to monitor mechanical stresses and strains in polymers via an optical signal enables the investigation of deformation processes in such materials and is technologically useful for sensing damage and failure in critical components. We show here that this can be achieved by simply blending polymers of interest with a small amount of a mechanochromic luminescent additive (Py-PEB) that can be accessed in one step by end-functionalizing a telechelic poly(ethylene-co-butylene) (PEB) with excimer-forming pyrenes. Py-PEB is poorly miscible with polar polymers, such as poly(ε-caprolactone) and poly(urethane), so that blends undergo microphase separation even at low additive concentrations (0.1-1 wt%), and the emission is excimer-dominated. Upon deformation, the ratio of excimer-to-monomer emission intensity decreases in response to the applied stress or strain. The approach appears to be generalizable, although experiments with poly(isoprene) show that it is not universal and that the (in)solubility of the additive in the polymer must be carefully tuned.

Experimental study on drilling of soft rocks

Drilling is commonly occurring material deformation process in vast range of industries including manufacturing, mining, petroleum, infrastructure, biomedical etc. Due to its three-dimentional nature and multi-axial deformation of material, drilling is a very complex process involving severe plastic deformation of material, high strain and strain rates, volume change, tempretarure gradient etc. In addition to this, drilling in rocks becomes further more complicated due to additional complexity added by brittle fracture. Therefore, it becomes important to have a complete understanding of the process and the effect of drilling paramerets on the material response in order to make it more energy efficient and improve the productivity in industrial applications.
 An attempt to understand the drilling in metals has been made by using a simplistic approach of decoupling the process into simpler process where, the penetration of the drill into the material and the rotatory motion has been correlated to indentation and cutting, respectively [1, 3, 8]. Similar framework has been adopted for rocks by many researchers where drill bits consist of many polycrystalline diamond compact cutters mounted on a tingesten carbide matrix [2, 5, 7]. In order to understand the interaction of these bits with rock, simplified models have been proposed for the cutters mounted on these bits [6]. This research work intends to understand the drilling mechanism experimentally by comparing drilling response (thrust force and torque) with the findings of intentation and cutting studies. Also, the force response (thrust and torque) were compared with the results obtained from the model.
 Drilling experiments were performed on samples prepared using gypsum, which is an ideal model material for soft rocks [4, 9]. Sample porosity was controlled by controlling the water content during casting of the samples (46 mm x 46 mm x 20 mm). Twist drills with helix angle of 300 and 600 were used. The diameter of the drill (6 mm) was kept significantly smaller (~ 8 times) than the width of the sample. The tip angle was kept constant (1200) for both the drills. The penetration rate was varied from 1 – 100 mm/min at constant rotation speed of 100 rpm. The penetration rate in combination with the rotation speed can be seen as depth of cut per revolution of the drill. The thrust force and torque were normalized with respect to the drill radius to compare the signatures with indentation [10, 11] and cutting [12] experiment results, respectively.
 On comparing normalized thrust and torque signatures with indentation and cutting results, a remarkable similarity was observed. Figure 1 and 2 show normalized thrust and normalized torque, respectively, as a function of depth of cut per revolution (penetration rate/ rotation speed). Similar to indentation results, Fig.1a shows that the thrust force has a strong dependence on material porosity but remained independent of drill geometry (Fig. 1b). This indicated that the drill geometry (which is responsible for cutting the material) does not influence the indentation part (vertical penetration). In contrast to this, the normalized torque showed dependence on both, drill geometry and porosity (Fig. 2) which was evident from studies performed gypsum cutting [12]. Also, the torque signatures were remarkably similar to cutting forces and cyclic peaks were observed which indicated cyclic removal of the chips during cutting. The drilling results were compared with the theoretical model as well [6]. However, results corresponding to the 300 helix angle drill did not align with the model predintions. Suitable modifications in the model was suggested. Based on some preliminary experiments performed by imaging the drilling process, it was believed that there exists an optimum helix angle for which the model presdintions hold good.
 This study shows experimentally that drilling, which is a complex 3 dimentional process, can be studied by decoupling it into simpler 2 dimentional processes: cutting and indentation. The similarity between the experimental findings of cutting, indentation and drilling suggest that the findings of cutting and indentation studies can be clubbed together and can be used to understand drilling better.

Nonlinearity of mechanical behavior of 3D-reinforced composites under compression

Modern technological capabilities make it possible to produce 3D spatially-reinforced for polymer composite materials. The tasks of experimental research and analysis of the deformation process of new composite materials for aviation purposes taking into account the nonlinearity of mechanical behavior become actual. The paper presents an experimental study of the mechanical compression behavior of composite material specimens made of 3D woven carbon fiber preforms using the pressure impregnation technology (Resin Transfer Molding method with a pairwise interlayer reinforcement and a longitudinal layer). Compression mechanical tests were carried out on specimens using a universal system of electromechanical testing Instron 5882 and a system of 3D analysis of displacement and strain fields on the surface. Tests were conducted in accordance with ASTM D 3410 recommendations and using specialized tooling. Consideration of nonlinearity parameter during experimental data processing is proposed. The importance of determining the values of critical deformation in compression as a parameter characterizing the moment of the beginning of fracture is noted. Comparison of carbon fiber composite materials made by the same technology from fibers and binders of different manufacturers has been carried out. The experimental diagrams "stress-strain" and their approximating dependences taking into account the nonlinearity function w are obtained. The type of functions w of the studied materials is defined, the linear approximation of dependence of functions w on deformation is substantiated. Values of strength limits, elastic modulus, nonlinearity coefficient and critical damage were obtained, statistical processing of the obtained results and their analysis were carried out.

A Pulsed Current Application to the Deformation Processing of Materials.

A review of studies on the electroplastic effect on the deformation process in various conductive materials and alloys for the last decade has been carried out. Aspects, such as the mode and regimes of electric current, the practical methods of its introduction into materials with different deformation schemes, features of deformation behavior accompanied by a pulsed current of different materials, structural changes caused by the combined action of deformation and current, the influence of structural features on the electroplastic effect, changes in the physical, mechanical, and technological properties of materials subjected to plastic deformation under current, possible mechanisms and methods of physical and computer modeling of the electroplastic effect, and potential and practical applications of the electroplastic effect are considered. The growing research interest in the manifestation of the electroplastic effect in such new modern materials as shape-memory alloys and ultrafine-grained and nanostructured alloys is shown. Various methods of modeling the mechanisms of electroplasticity, especially at the microlevel, are becoming the most realistic approach for the prediction of the deformation behavior and physical and mechanical properties of various materials. Original examples of the practical application of electropulse methods in the processes of drawing, microstamping, and others are given.

Study on the Deformation and Fracture Mechanisms of Plastic Metals Considering Void Damage

Fracture initiation in plastic metals is attributed to the development of voids. Analyzing the nucleation and growth processes of voids facilitates the study of plastic deformation and fracture mechanisms in metal materials. Uniaxial tensile tests were conducted on two high-quality carbon structural steels, and the microfracture surface morphology of the tensile specimens was observed by using a scanning electron microscope (SEM). From the perspective of vacancy condensation, the nucleation mechanism of voids in the absence of inclusions or particles was analyzed. Based on the continuum damage mechanics theory and the Rice–Tracy (R-T) model, a damage parameter considering the void volume fraction was derived, and a plastic potential function, hardening curve, and constitutive model for the plastic deformation process of the plastic metal material were established. Based on the uniaxial tensile test data of the two sheets of high-quality carbon steel, the strain range data in the hardening stage were converted into true stress–plastic strain data, and the established hardening curve was used to fit the true stress–plastic strain data. The results showed good agreement between the established hardening curve and the experimental results, which effectively reflected the deformation process of ductile fractures in plastic metal materials.

Development of 1D bounding surface model for lattice spring model on predicting rock failure under cyclic loading

A sound interpretation of the deformation and failure of rock material subjected to cyclic loadings is of great importance when predicting the long-term stability of rock structures. The bounding surface model is generally utilized to depict the mechanical behaviour of rock subjected to cyclic loadings. In this work, a simplified 1D bounding surface model is developed into a 4D lattice spring model (4D-LSM) to predict rock failure under cyclic loading. To better represent the nonlinear behaviour of rock material, a microcrack model is also introduced in the simplified 1D bounding surface model, together with a macro strength criterion and a cohesive zone model to represent the failure process of the rock. GPU-based parallel computing is realized to accelerate the time-consuming numerical simulation. The numerical results indicate that the proposed model reproduces the deformation and failure process of rock material under different cyclic loading paths. Moreover, the fatigue life of the rock under different conditions is predicted, including different stress levels, confining stresses, and preexisting macro joints. These numerical results reveal that the simplified 1D bounding surface model not only satisfactorily describes the mechanical response of rock under cyclic loading (like in classical continuum-based constitutive models) but also shares the advantage of the discrete-based numerical model in modelling the fracture and failure processes of rock under cyclic loading. This approach could also be used in other discrete numerical models, such as the discrete element model (DEM).

Review of Particle-Based Computational Methods and Their Application in the Computational Modelling of Welding, Casting and Additive Manufacturing

A variety of particle-based methods have been developed for the purpose of computationally modelling processes that involve, for example, complex topological changes of interfaces, significant plastic deformation of materials, fluid flow in conjunction with heat transfer and phase transformation, flow in porous media, granular flow, etc. Being different from the conventional methods that directly solve related governing equations using a computational grid, the particle-based methods firstly discretize the continuous medium into discrete pseudo-particles in mathematics. The methods then mathematically solve the governing equations by considering the local interaction between neighbouring pseudo-particles. Such solutions can reflect the overall flow, deformation, heat transfer and phase transformation processes of the target materials at the mesoscale and macroscale. This paper reviews the fundamental concepts of four different particle-based methods (lattice Boltzmann method—LBM, smoothed particle hydrodynamics—SPH, discrete element method—DEM and particle finite element method—PFEM) and their application in computational modelling research on welding, casting and additive manufacturing.

Artificial neural network potentials for mechanics and fracture dynamics of two-dimensional crystals ** ** Notice: This manuscript has been authored by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a nonexclusive, paid-up, irrevocable, world-wide license

Understanding the mechanics and failure of materials at the nanoscale is critical for their engineering and applications. The accurate atomistic modeling of brittle failure with crack propagation in covalent crystals requires a quantum mechanics-based description of individual bond-breaking events. Artificial neural network potentials (NNPs) have emerged to overcome the traditional, physics-based modeling tradeoff between accuracy and accessible time and length scales. Previous studies have shown successful applications of NNPs for describing the structure and dynamics of molecular systems and amorphous or liquid phases of materials. However, their application to deformation and failure processes in materials is still uncommon. In this study, we discuss the apparent limitations of NNPs for the description of deformation and fracture under loadings and propose a way to generate and select training data for their employment in simulations of deformation and fracture simulations of crystals. We applied the proposed approach to 2D crystalline graphene, utilizing the density-functional tight-binding method for more efficient and extensive data generation in place of density functional theory. Then, we explored how the data selection affects the accuracy of the developed artificial NNPs. It revealed that NNP’s reliability should not only be measured based on the total energy and atomic force comparisons for reference structures but also utilize comparisons for physical properties, e.g. stress–strain curves and geometric deformation. In sharp contrast to popular reactive bond order potentials, our optimized NNP predicts straight crack propagation in graphene along both armchair and zigzag (ZZ) lattice directions, as well as higher fracture toughness of ZZ edge direction. Our study provides significant insight into crack propagation mechanisms on atomic scales and highlights strategies for NNP developments of broader materials.

Effect of strain rate on dynamic recrystallization mechanism of Mg-Gd-Y-Sm-Zr alloy during hot compression

Strain rate plays an important role in the hot deformation process of materials. In this work, hot compression experiments were conducted on Mg-Gd-Y-Sm-Zr alloy at the strain rates of 0.001–1 s−1 by Gleeble thermal simulation machine. The deformation behavior and microstructure evolution were studied in detail, and the dynamic recrystallization (DRX) mechanism was discussed. The results show that the flow stress of the alloy increases with the increasing strain rate. Deformation bands (DBs) are formed inside some grains at the strain rates of 0.1–1 s−1, which increase interfaces in the microstructure and hinder the dislocation movement. DRX grains are formed at the regions of DBs and original high angle grain boundaries (HAGBs). The DRX mechanism at high strain rates includes DBs induced DRX and discontinuous dynamic recrystallization (DDRX). At low strain rates and small strain, the dislocations first accumulate at the original HAGBs, and DDRX occurs in the alloy. The subgrains with low angle grain boundaries (LAGBs) are formed inside the initial grains through sufficient dynamic recovery (DRV) as strain increases, and LAGBs will gradually transform into HAGBs with the increasing misorientation angle. The DRX mechanism shows the synergistic effect of DDRX and continuous dynamic recrystallization (CDRX) at low strain rates.

Bending of a plate from a functionally heterogeneous material in the presence of large deformations

Details and elements of structures, which are made of functionally heterogeneous materials and have the property of shape memory and behave pseudo-elastically, may be under the influence of complex loads in the process of manufacturing and operation. Uneven heating of bodies in combination with force factors can lead to large deformations of the material and complex deformation processes. The existing models of the behavior of such elements do not take into account the nonlinearity of geometric relationships and are unsuitable for use with large deformations.
 The article deals with the bending of a plate of finite dimensions from a functionally heterogeneous material in the presence of large plastic deformations. The simulation of plate behavior is based on a nonlinear phenomenological model that describes the properties of shape memory alloys and the thermos-pseudo-plastic behavior of the material at a point. A diagram of a pseudo-elastic material consisting of three curved sections is used.
 The first feature of the formulation of the problem of specifying the area of geometric nonlinearity is the formulation of the boundary conditions around the support. If for a linear problem they are set only along the support line, then to refine the geometrically nonlinear solution, the zero vertical displacements of the plate points and, accordingly, the speed of movement were set in the vicinity of the area of contact with the support. The second feature of the refinement is a significant reduction in the number of coordinate integration steps (up to 5%). At the same time, in order to fulfill the condition of stability, a proportional reduction of the integration step over time is necessary. For a reliable comparison of results, it is necessary to increase the number of time integration steps while decreasing the integration steps by coordinates. This problem was solved using a sequence of numerical experiments. The third feature consists in solving the additional problem of interpolation of the required values in the nodes of the new finer grid by the corresponding value in the nodes of the main grid. This problem is solved using a two-dimensional spline function.

Molecular dynamics simulation of nanoindentation on nano-twinned FeCoCrNiCu high entropy alloy

ABSTRACT Twin boundary (TB) plays an important role in the deformation process of materials. In this paper, molecular dynamics (MD) simulation was used to investigate the nanoindentation deformation behaviour of single-crystal FeCoCrNiCu high entropy alloy (SC-HEA) and nano-twinned FeCoCrNiCu high entropy alloy (NT-HEA) with different twin spacings. It is found that the main characteristic of plastic deformation of SC-HEA is the dislocation loop emission. The dislocation movement and distribution of NT-HEA are very different from that of SC-HEA. We found that partial dislocation slip parallel to the twin boundary (PSPTB) and twin partial slip (TPS) can lead to alloy softening. The hindrance of the TB causes the dislocation to slip within a single layer (known as confined layer slip, CLS), which strengthens the material. In the process of nanoindentation, the softening and strengthening mechanisms are constantly competing. When the twin spacing is larger than 1.23 nm, CLS dominates the competition with the hardening mechanism, and the hardness of the material increases with the decrease of the twin spacing. When the twin spacing is less than 1.23 nm, the dominant mechanism of plastic deformation changes to the softening mechanism controlled by TPS, and the hardness thus decreases as twin spacing increases.

Experimental and Theoretical Investigation of Viscoelastic Damper by Applying Fractional Derivative Method and Internal Variable Theory

Viscoelastic dampers are conventional passive vibration control devices with excellent energy dissipation performance. The fractional derivative has a simple form and high accuracy in the modelling of viscoelastic materials/dampers. The internal variables reflect the internal state evolution of materials, and are often used to analyze the deformation and thermal process of materials. In the present work, the mechanical properties of a plate-shear-type viscoelastic damper at room temperature are tested under sinusoidal displacement excitations. The impacts of frequency and displacement amplitude on the dynamic properties of the viscoelastic damper in a wide frequency domain (0.1–25 Hz) are investigated. The higher-order fractional derivative model and the temperature–frequency equivalent principle are employed to characterize the frequency and temperature influence, and the internal variable theory considering the internal/microscale structure evolutions is introduced to capture the displacement affection. The higher-order fractional derivative model modified with the internal variable theory and temperature–frequency equivalent principle (ITHF) is accurate enough in describing the dynamic behaviors of viscoelastic dampers with varying frequencies and displacement amplitudes.

A comparative study on modeling approaches towards laser-assisted machining

Finite element method (FEM) is widely used in machining processes as it can efficiently respond to the thermomechanical deformation and removal processes of materials. In this paper, FEM simulation analysis for laser-assisted machining (LAM) of Ti6Al4V alloy is carried out using two different modeling approaches: the sequentially coupled simulation (SCS) and the predefined fields coupled simulation (PFCS). The results of temperature, cutting force and chip morphology are obtained by these different approaches and verified by experiments. By analyzing the errors of the two approaches, the results show that the cutting force and chip morphology errors of the SCS method are 16.14% and 11.11%, respectively, while the errors of the PFCS method are 7.58% and 16.67%. However, neither of these approaches can fully simulate the complete LAM process. Therefore, a fully coupled simulation (FCS) approach needs to be developed to overcome the shortcomings of the above two methods.

Charge-Sensitive Technique for Deformation Processes’ Study

Surface charge can be used as an information parameter about the change in the state of the material under the action of mechanical stresses. The aim of the work was to develop methods for studying deformation processes in metallic and polymeric materials using a charge-sensitive method.Experimental studies of deformation processes under tensile, compressive and impact loads were carried out on samples of various materials: aluminum alloy of AMg2 grade, steel of grade 08PS, high-pressure polyethylene of grade 12203-250 and samples of composite materials based on it, F4 polytetrafluoroethylene. As a research method, the analysis of changes in the relative values of the surface electron work function in the case of metals and the surface electrostatic potential in the case of polymers and composite materials is used. A scanning modification of a charge-sensitive probe is used as a measuring instrument.The results of experimental studies of materials in a stress-strain state demonstrate the high efficiency of the proposed method. The research methodology makes it possible to detect local changes in the surface potential of the material in the area of deformations, which are not detected on a macroscopic scale using standard methods. The results obtained can serve as a basis for the development of new methods and techniques for studying the mechanical properties of both metals and dielectric materials.

Research of Mechanical Properties of the Aluminium Alloy Amag 6000 Under the Plane Stress State Conditions

Today's demands directly encourage to utilize the light alloy materials in industrial production. In the automotive industry, there is an increasing tendency to reduce the total weight of the car and thus also the weight of the individual car-body parts. A correct description of the material deformation behaviour with respect to the different stress states is very necessary for the own possibility to use these materials in the production. This paper describes a measurement of the mechanical properties and deformation behaviour of aluminium alloy Amag 6000 under the plane strain conditions. Thus these properties are monitored and evaluated by means of the plain strain tensile test. In this case, the plane strain is achieved by the shape concept of the testing specimen, which is loaded by the uniaxial tensile stress state using a standard testing device. The determined mechanical properties and the resulting stress-strain curves of the material under the plain stress state can be further used at defining material models for a more accurate description of the material deformation process during the sheet metal forming process.

Ballistic Resistance of Composite Materials Tested by Taylor Anvil Test

This study is focused on testing the ballistic resistance of composite materials to define their limit thicknesses according to the US STANDARD NIJ 0101.06, level III. The materials Twaron CT 747, Twaron CT 747 TH110 and Endumax Shield XF33, which are widely used in the manufacture of the ballistic protection systems, were tested. A method known as the Taylor Anvil Test (TAT) was used to verify their ballistic resistance. The missile 7.62 mm M80 was used to test the ballistic resistance of these materials. Within the experimental part, the deformation processes of composite materials were examined after impact by this missile. The value of the traumatic effect according to the US STANDARD NIJ 0101.06 was also measured. The results of the experiment provide an idea of the ballistic resistance of selected materials. Based on the results, TAT proved to be the perspective measurement method for further development and optimalization of the multilayer composite armor.

Numerical prediction of cavitation damage based on shock-induced single bubble collapse near solid surfaces

The prediction of cavitation damage through bubble collapse impact loads (BCIL) is essential, because it opens the opportunity to develop a phenomenological model that can be useful to improve the design process of hydraulic machinery components. Owing to the fast process and small-scale phenomena, direct measurement of the BCIL is greatly challenging if conducted through experimental methods. This study aims to reveal the underlying deformation process of solid materials under a single BCIL using a coupled multi-material hydrocode solver. Three different material constitutive models – purely elastic, elasto-plastic, and strain-hardening – were investigated through various types of metals and polymers. A detached single air bubble was placed near the solid surface inside a long and narrow tube. A planar shockwave was introduced to induce the bubble to collapse, resulting in BCIL that is high enough to cause plastic deformation on the solid surfaces. Measured BCILs from solid material cases show good agreement with the cavitation erosion test result of A1050, SS400, Epoxy resin, PP, and HDPE. These findings indicate that, in the case of metals, the deformation process can be inferred to acoustic impedance since impact energy evaluation shows no significant change when material plasticity is introduced. However, in the case of polymers, the deformation process is greatly influenced by yielding.

(Invited) 3DIC Hierarchical Thermal and Mechanical Analysis with Continuum and Atomistic Modeling

3D IC heterogeneous integration technologies employ numerous materials with widely varying thermal and mechanical properties and distinct deformation behaviors. During 3D integration processes, the constituent materials undergo various thermal cycles. Because of thermal expansion coefficient mismatch, the materials are essentially subject to mechanical loadings for these thermal ramps. The resulting chip, package, and board interactions lead to 3D stack warpage, silicon mobility variation, and material damage. Under operation conditions, heat can be trapped between insulation layers and leads to nonuniform temperature rises. Elevated local temperatures can change carrier mobility, relax mechanical stress, and affect material deformation behaviors. Consequently, these local temperature rises can affect device performance, structure integrity, and material reliability. To accurately assess these thermal and mechanical effects, extract design rules, optimize designs, and develop performance and reliability mitigation methodologies, it is of paramount importance to characterize material deformation and interface de-bonding behaviors, map chip temperature distributions, and analyze stress hotspot evolutions during integration process and under operation conditions while developing 3D IC integration technologies [1].In this study, a multiscale hierarchical modeling approach is assembled to analyze thermal, mechanical, and material deformation and interface de-bonding behaviors under 3D integration process and operation conditions for a newly designed 3D IC package with a 2nm SOC die copper-bonded on an RDL interposer [2]. The 3DIC structures are constructed directly using GDSII design and ITF technology data [3]. Each structural layer is divided into small smear tiles. Each tile is represented by anisotropic thermal and mechanical properties that depend on local feature patterns in the tile. Under given operation conditions, power grids are generated and used as heat sources for thermal analysis. For multiscale hierarchical modeling, the global thermal and mechanical analyses that call for coarse grain resolution are first performed. The subsequent local analyses that provide fine grain resolution in areas of interests utilize boundary conditions that are extracted from the global analyses. The material deformation and interface de-bonding behaviors are simulated using molecular dynamics [4]. Several 3D integration design options are explored. The 3D configuration effects on chip temperature distributions during operations, stack warpages, silicon mobility variations, and chip package interaction induced stress hotspots are examined. The elevated temperature impacts on material deformation and de-bonding process are also investigated.