Preliminary List of Abstracts (Alphabetical Order)

MULTISCALE MATERIAL MECHANICS IN THE 21ST CENTURY: OLD IDEAS FOR NEW MODELS ACROSS MATERIALS, PROCESSES AND SCALES

On account of their uniqueness, during the last 30 years, the concept of composites has been exceptionally appealing to many researchers, technologists and entrepreneurs. Consequently, the number of scientific and technological investigations in the field has grown profusely, in a widespread fashion, with numerous attempts in all fields, namely, polymer-, ceramic- and metal-matrix composites. However, to a degree, this enthusiasm has led to a misconception in that composites are a synonym of a simple mixture of materials and that it refers only to structural applications. The recent literature shows that a broad range of thermal and functional applications are under investigation, in addition to the structural ones, upon which most of the current literature and syllabi are based. In tandem with this boom, partly because of the advent of nanoscience and nanotechnology, a number of new terms has been used. This fact suggests the need for an update in the classification of composites and in the review of the principles upon which they are founded, and perhaps, in redefining some previous concepts and the establishment of new ones. On the basis of a recent review of the literature - bibliographical references and statistics of old and new books, as well as specialized journals on the subject -, in this contribution, authors put forward an updated classification, review the essentials of composites and provide illustrative examples from ancient to the most recent applications. To conclude, an insight into the future prospects on the subject is painstakingly delineated.

In this work, we discuss two classes of methods to reduce the complexity of (multi scale) fracture simulations. In a first part, we discuss algebraic model reduction. We show that algebraic model reduction, such as the proper orthogonal decomposition, cannot be used directly because of the lack of correlation introduced by the damage or cracks. We demonstrate the use of proper orthogonal decompositions by subdomains as a candidate to reduce computational expenses in non-linear fracture simulations whilst controlling the error level. In a second part, we propose an adaptive hybrid multi scale method for modelling fracture in a heterogeneous material that is composed of orthotropic grains with cohesive interfaces between the grains. Instead of a direct solver, FE2 method [1] based on homogenisation is employed in order to compute the effective behaviour of the heterogeneous microscopic material on the coarser scale. At this scale, the modelling error due to the homogenisation is still low [3]. The coarse scale is discretized with unstructured triangular finite elements, and adaptive mesh refinement is used to control the discretization error. While the mesh refinement keeps the discretization error within a certain range, the modelling error increases due to the fact that by refining the coarse elements, the scale separation assumption, which is a key issue for homogenisation, may no longer be fulfilled [4].Whereas the modelling error is inversely proportional to the size of the coarse elements, a critical element size can be found that corresponds to the critical value of the modelling error. A critical zone emerges when the size of a coarse element reaches the critical size, or if the underlying representative volume element of the microstructure loses stability due to localisation (lack of scale separation). Thereafter, a zoom-in process is triggered that replaces the corresponding coarse elements of the critical zone with high resolution micro scale mesh to which it glues the coarse scale mesh through a strong coupling technique using Lagrange multipliers [5]. The high resolution region can gradually be extended to include the newly emerging critical zones. A local arc-length technique is adopted to trace the highly non-linear curve of the global load-displacement by controlling the opening of microscopic cohesive cracks in the fully resolved regions.The proposed adaptive multi scale method allows us to introduce progressive discrete micro cracks at the macro scale. The unstructured mesh enables us to model problems with non-regular shapes, and the arc-length method, defined over multiple scales, allows the regularisation of softening problems that are treated in quasi-statics. We exercise this method on the simulation of polycrystalline fracture, where each grain is considered orthotropic and compare results to direct numerical simulation.

The mechanical behaviour of complex materials, characterized at finer scales by the presence of heterogeneities of significant size and texture, strongly depends on their microstructural features. By lacking in material internal scaleparameters, the classical continuum does not always seem appropriate to describe the macroscopic behavior of such materials, taking into account the size, the orientation and the disposition of the micro heterogeneities. This calls for the need of non-classical continuum descriptions obtained through multiscale approaches aimed at deducing properties and relations by bridging information at proper underlying micro-level via energy equivalence criteria. Firstly, focus will be on physically-based corpuscular-continuous models as originated by the molecular models developed in the 19th century to give explanations 'per causas' of elasticity (Cauchy, Voigt and Poincare [3]). Current researches in solid state physics as well as in mechanics of materials show that energy-equivalent continua obtained by defining direct links with lattice systems are still among the most promising approaches in material science. The aim here is to point out the suitability of adopting discrete-continuous Voigt like models, based on a generalization of the so-called Cauchy-Born rule used in crystal elasticity and in classical molecular theory of elasticity, in order to identify continua with additional degrees of freedom (micro-morphic, multi-field, etc.), which are essentially non-local models with internal length and dispersive properties [7] and which, according to the definition in [1], are called non-simple continua. It will be shown as microstructured continuous formulations can be derived within the general framework of the principle of virtual work which,on the basis of a correspondence map relating the finite number of degrees of freedom of discrete models to the continuum kinematical fields, provides a guidance on the choice of the most appropriate continuum approximation for heterogeneous media, allowing us to point out in particular when the micro-polar description is advantageous [4,6]. Basing on the proved effectiveness of continuum micropolar modelling, some further developments concerning different homogenization methods based on x the solution of boundary value problems, defined at the micro-level and derived from macrohomogeneity conditions of the Hill-Mandel type generalized in or 1 der to take into account of relative rotation and curvature degrees of freedom, will be successively introduced. These approaches show to be particularly suitable to deal with composite materials characterized by internal structure made of randomly distributed particles of significant size and orientation [5]. It will be shown as a statistically-based multiscale procedure specifically conceived to simulate the actual microstructure a of a random medium at various mesoscale levels allow us to detect the size of representative volume elements, otherwise unknown [2],and to estimate the constitutive moduli of the energy equivalent micro-polar continuum. Some applications of the mentioned approaches to fiber reinforced composite materials, ceramic matrix composites and masonry-like material will be reported and discussed.

It is well-known that micron-sized metallic single-crystals exhibit a smaller-being-stronger size effect. For single crystals, the yield strength in general varies with specimen size approximately as a power law. For specimens containing microstructures, however, how the internal microstructure length scale, such as grain size and precipitate spacing, affects the strength of small metal volumes is an open area. In this work, the relevant experimental and theoretical efforts are reviewed. The results reveal intricate coupling effects between the external specimen size and the internal microstructural length scales. Essentially, the strength and plasticity of small metal volumes containing real microstructures can significantly deviate from their bulk counterparts, as well as from monolithic single crystals.

We report on experimental study and theoretical analysis of pentagonal (five-fold) symmetry in micro- and nanocrystalline objects: Metallic particles and elongated rods. The observations of electrodeposited small particles with decahedral and icosahedral morphology and rods with pentagonal cross-section, are presented. Internal structure of pentagonal objects is explained as a result of multiple twinning in a material with FCC crystal structure and formation of disclination defects. Knowledge on the disclination content of pentagonal objects allows one the elaboration of qualitative and quantitative models for their structural evolution and stability. To build such models, elasticity of disclination in finite size bodies is discussed in full details. Various relaxation processes leading to the diminishing of the internal energy of disclinated particles and elongated rods are proposed. These processes include the emergence of a hole at dislocation core, generation of additional dislocation defects inside pentagonal objects, and formation of the crystal lattice-mismatch layer on the particle or rod surface. The operation of the listed relaxation mechanisms is documented by available experimental data.The content of the report is based mainly on the following publications:[1] V.G. Gryaznov, J. Heydenreich, A.M. Kaprelov, S.A. Nepijko, A.E. Romanov, J. Urban,Cryst. Res. Techn. 34 (1999) 1091.[2] A.E. Romanov, A.L. Kolesnikova, Progr. Mater. Sci. 54 (2009) 740.[3] L.M. Dorogin, S. Vlassov, A.L. Kolesnikova, I. Kink, R. Lohmus, A.E.Romanov, Phys. Stat. Sol. (b) 247 (2010) 288. [4] A.E. Romanov, A.A. Vikarchuk, A.L. Kolesnikova, L.M. Dorogin, I. Kink, E.C. Aifantis, J. Mater. Res. 27 (2012) 545.[5] A.E. Romanov, L.M. Dorogin, A.L. Kolesnikova, I. Kink, I.S. Yasnikov, A.A. Vikarchuk, Tech. Phys. Lett. 40 (2014) 174.

It is shown in [1] by a DFT-based calculation that in-plane stretching induces softening of the bending rigidity of graphene. In this contribution, working in the framework of discrete structure mechanics, we develop a model that predicts and allows to estimate softening effects in graphene monolayers. To keep our developments as simple as possible, we restrict attention to bending+traction problems in the armchair (A) and zigzag directions (Z) and for symmetrical load distributions.Given a REBO potential V(y), with y a string of internal variables such as bond lengths, bond angles, and dihedral angles, we express y in terms of a string x of suitable Lagrangian coordinates, and we write the total energy functional of the system in the form W(x)=V(y(x))-fad(x), where the load potential is the inner product of d, a string of generalized displacement parameters, and the dual string of dead loads f. As usual in structure mechanics, the system's equilibrium shapes are obtained by setting to zero the first gradient of W with respect to x; Their stability is assessed by checking the positivity of the Hessian of W. These nonlinear equilibrium equations are given a precise mechanical interpretation in terms of stresses and prestresses; A representative numerical solution is given for V the second-generation Brenner potential [3], that is, for the most common empirical potential, used to perform MD simulations for carbon-based materials. Whatever V, we give an analytical necessary and sufficient condition for softening of the bending rigidity of graphene in case of the coupled bending-traction problems we study. We also show that such a condition is satisfied by the second-generation Brenner potential - a result consistent with the DFT calculations of [1]. We also argue that the same approach can be used to analyze some delicate issues in the mechanics of carbon nanotubes, such as their exact geometry, prestress level, and zipping-unzipping energy. In connection with the last of these issues, we recall from [2] that a technique to produce nanoribbons is based on an oxidative unzipping process that discloses the presence of a latent energy in the nanotubes one starts off with; Our formulation yields both a justification and a quantitative evaluation of that energy.

This report presents an exact closed-form solution for the Eshelby problem of a polygonal inclusion with a graded eigenstrain in an anisotropic piezoelectric full or half-plane with a traction-free surface condition. Using the line-source Green's function, the line integral is then carried out analytically for the linear eigenstrain case, with the final expression involving only elementary functions. Finally, the solutions are applied to the quantum wires (QWRs) of square, triangular, circular and elliptical shapes within semiconductor GaAs substrates respectively, with results clearly illustrating that there are various influencing factors on the induced fields. The present solution should be particularly appealing to the more realistic nanoscale quantum-wire structure analysis where strain and electric fields could be induced by the non-uniform misfit strain.

When running a standard Molecular Dynamics simulation, information about the constitutive nature of the material under study is embodied in the chosen intermolecular potential; In D(issipative)MD, this information is complemented by choosing, essentially by fiat, a mechanism of microscopic friction. On the other hand, in continuum mechanics, viscoelastic response is described by well-known prescriptions for the functional dependence of stress on deformation history. To put it simply, the consistency issue I address has to do with deciding when the same material is described by two sets of constitutive prescriptions, the one formulated in the fashion of statistical mechanics the other of continuum mechanics.

Informatics is a new area of interdisciplinary study that integrates computer science, information science, and some domain area to provide new understandings and to facilitate knowledge discovery. Materials informatics can be thought of as a tool for material scientists to gain new understandings of their data through the use of a myriad of machine learning approaches, integrated with new visualization schemes, more human-like interactions with the data, and guided by domain experts. It can also accelerate the research process and minimize data handling. All of this is fueled by the unprecedented growth in the field of information technology and is driving the interest in the application of knowledge representation, knowledge discovery and data mining, machine learning, information retrieval, semantic technology etc., in the engineering disciplines.

Deformation and fracture of materials exhibit temporal and spatial features. Based on the concept of structural hierarchy and relaxation model, the relationship between spatial and temporal properties of deformation and fracture of rock-like materials is investigated. It has been revealed that the relationship between spatial and temporal scales of deformation and fracture of quasi-brittle materials is in agreement with the available experimental data. This paper points out that the essence of the relationship between spatial and temporal scales of deformation and fracture of quasi-brittle materials lies in the finiteness of crack propagation velocity. From the viewpoint of structural hierarchy, size effect may be considered as the realization of the weakened structural surface strength of smaller scale structural elements with the decrease of the sample size. The essence of strain rate effect is that because of the finiteness of crack propagation velocity, the increase of loading rate, accordingly, the increase of strain rate activates the deformation and fracture process of smaller scale elements before the macro-fracture of the sample. The dynamic strength of material is the strength of weakened structural surface of the smallest activated elements before the macro-fracture of the sample as a whole. This investigation examines the size and strain rate effects on strength of quasi-brittle materials, which would give better understanding of dynamic phenomena of deformation and fracture of quasi-brittle materials.

Resorting to the approximations currently accepted when dealing with deformations of a continuum in which displacements are assumed to be infinitesimal, it goes unnoticed that the observable (measurable) volume change implied by deformation is equal to the algebraic sum of two contributions to which a different physical meaning should be attributed. Without making use of the above approximations, one unveils that in a system undergoing deformation at least one of the above contributions is different from zero. A convenient description of the deformation allows both the definition of the conditions at which one of the contributions vanishes, and the mathematical determination of the common absolute value of the two contributions during isochoric deformations. A corresponding description of the internal reactions to forces and couples acting on the deforming continuum is strongly suggested by such a description of deformation.Needless to say, the recognition of the fact that one of the two contributions to volume change is related to entropy increase and the other one with entropy decrease is a not ignorable prerequisite for a reliable approach to the physics of deformation.

It is gradually getting clear that the macroscopic description of materials requires additional thermodynamic parameters, entropy of microstructure and temperature of microstructure. It was claimed that there is "one more law of thermodynamics": Entropy of microstructure must decay in isolated thermodynamically stable systems. Such behavior is opposite to that of thermodynamic entropy. This talk will illustrate the concepts of microstructure entropy and microstructure temperature by several physical examples. The experiments will be described that confirm the decay of microstructure entropy in grain growth of polycrystals.

Our discovery of the "Current Spike" was first highlighted in the Letters to Nature Nanotechnology (Nowak et al. Vol.4 /2009/; Chrobak, Nowak, et al. Vol.6 /2011/) and offers an enhanced understanding of the link between nanoscale mechanical deformation and electrical properties. Our conclusions point to key advances in pressure-sensing, pressure-switching, and unique phase-change applications in next-generation electronics. It is a very encouraging demonstration of the way in which nanomechanics contributes to electronics and optoelectronics developments. The onset of plasticity is traditionally understood in terms of dislocation nucleation and motion. This study of nanoscale deformation has proven that initial displacement transient events occurring in metals are the direct result of dislocation nucleation. Our research shows that this is not always true: Instead of dislocation activity, nanoscale deformation may simply be due to transition from one crystal structure to another, as predicted for GaAs by our earlier atomistic calculations. The presented results lead to a major shift in our understanding of the elastic-plastic transition as well as inherent formation of a Schottky barrier in semiconductors under localized high pressures. The results showing the dramatic impact of crystal imperfections on the functional properties of GaAs motivated our further study into the onset of incipient plasticity in Si nanoparticles. Molecular Dynamics calculations and supporting experimental results reveal that the onset of plasticity in Si nanospheres with <130 nm diameter is governed by dislocation-driven mechanisms, in striking contrast to bulk Si where incipient plasticity is dominated by phase transformations. We established the previously unforeseen role of "nanoscale confinement" governing a transition in mechanical response from "bulk" to "nanovolume" behavior.

In the seminal work on the equilibrium of an elastic bar, Ericksen (1975) revealed that for an up-down-up stress-strain relation multiple-phase states can co-exist. It was found: (1) The stable states are piecewise homogeneous deformations with strain discontinuity. (2) The stress is exactly the Maxwell stress in the stable states. (3) There are infinitely many stable states, and the number of discontinuities of strain is arbitrary. The present work considers the stress-induced phase transitions in a slender 3-D shape memory alloy cylinder by taking into account both macroscopic and microscopic effects (the latter is through the volume fraction of martenisite phase). A main purpose is to examine whether more conclusive results (in comparison with Ericksen's 1-D results) can be achieved. More specifically, a constitutive model in literature is adopted, which leads to a 3-D mechanical system with an internal variable. By utilizing the smallness of the characteristic axial strain and aspect ratio, the complex governing system is reduced to three linear systems for three different regions (austenite, martensite and phase transition regions). Then, we concentrate on the inhomogeneous state with one transformation front, for which the cylinder contains one austenite region, one martensite region. Mathematically, determining the solutions becomes solving a nonlinear eigenvalue problem with a group of eigen parameters. When the two interfaces are planar, we manage to construct the closed-form solutions. The analytical solution reveals some important theoretical insights, comparing with Ericksen's 1-D results. For example, although the axial stress is inhomogeneous in the cross section for the current 3-D setting, for the optimal state (which has the smallest energy value), the average axial stress is still the 1-D Maxwell stress. Also, unlike the 1-D case of Ericksen's bar problem, for which there are infinite-many stable states with the same energy value, the current 3-D problem only has one optimal state although there are still infinite-many solutions. Gradient models are popular in numerical simulations but it is difficult to choose the proper gradient parameter(s). Here, we also make a comparison of our 3-D analytical results with those of a 1-D gradient model, which leads to a plausible choice of the gradient parameter.

Polymer/layered silicate nanocomposites are of particular interest among different nanohybrids because of their anticipated superior properties. Mixing polymers with layered inorganic materials can lead to three different types of structure, depending on the specific interactions between the constituents: Phase separated, intercalated and exfoliated. Intercalated hybrids are also model systems for the study of the static and dynamic properties of macromolecules in nano-confinement. We describe our recent efforts to elucidate the effects of severe confinement utilizing hydrophilic nanohybrids of PEO or hyperbranched polymers mixed with Na+-MMT. Intercalated hybrids with mono-, bi- and tri-layers of chains are obtained for all compositions covering the complete range from pure polymer to pure clay. Severe confinement influences significantly the structure of the polymer: The PEO chains intercalated within the inorganic galleries as well as those in close proximity to the outside walls are purely amorphous; It is only when there is large amount of excess polymer outside the completely filled galleries that the bulk polymer crystallinity is abruptly recovered. The dynamics of the polymers confined within the galleries is probed by quasi-elastic neutron scattering and dielectric spectroscopy. The very local dynamics of the confined chains show similarities with those in bulk, whereas the segmental dynamics, probed at temperatures above the bulk Tg, depend very strongly on the polymer/inorganic interactions varying from much faster to much slower or even frozen dynamics as the strength of the interactions increases.

Sextus Empiricus is the most eminent representative of the ancient scepticism, which is a Post-Classical, Hellenistic philosophy based on the criterion of life, the experience and the analysis of phenomena, sharply opposed to a purely theoretical pursuit of dogmatic philosophy. The term skeptisism is a derivative of the noun, skepsis, which means thought, examination, inquiry, consideration, meditation and investigation. The skeptical school was connected for a long period of time with the Empirical school of physicians, who based the good medical practice on the clinical experience rather than on the theoretical erudition. Sextus, who lived in Alexandria, Athens and Rome was an empiricist who adopted scepticism, as philosophical doctrine and way of life in view that the sceptical way was characterized by persistent commitment to investigate the truth, based on objective arguments and real evidence. The ancient sceptics, avoiding dogmatism, used to search for the truth, posing many dialectic questions about knowledge and beliefs, feeling that all arguments could be opposed by other strong arguments of the same persuasive force and validity, underlining the dynamics of the philosophical investigation and dialectics. Phenomena are the only things, which the sceptic thinkers do not deny, since they constitute the appearance of objects. Sextus' writings are the main source of most of our knowledge of ancient scepticism and the other philosophical tendencies of the Hellenistic era. Sextus offers thoroughly a general overview of scepticism, describing and explaining the meaning of the sceptical investigation, the value of suspension of judgment and the importance of the sceptical dialectics. Sextus insists that the skepticism does not accept or reject any impression and substantially does not affirm or deny anything. Sextus claims that appearances are the practical criteria of approaching to the truth and by the continuous investigation the thinker is prevented from mental or psychological inactivity. The only wise way of life is to suspend judgment, regarding everything, therefore never facing the risk of being wrong in anything. The human being has the innate capacity for perception, thinking, analysis of the phenomena, ability to distinguish what is true and what is false and to meditate avoiding dogmatism. According to Sextus doctrines, logic is based on phenomena and criteria. According to Sextus, science is considered as being the main source of pure knowledge, underling at the same time the relativity of the scientific data. Science, therefore, could not presume to provide the authoritative truth and all its issues must be understood from a dialectical perspective, since whatever is debatable may concern reality. The scientific methodology consists of investigation, as starting point, of equipollence, a balancing estimation of all positive and negative aspects, of suspension of judgment and of tranquility of mind and imperturbability. Always reality has to be investigated but appearance must be accepted without any debate, since it is clearly obvious. Every effort to approach the truth is feasible only by assessing the phenomena, since absolute reality could never be known. Sextus insists that any argument requires definite proof, precisely proven, otherwise it might lead to an infinite regression, resulting to fall into a vicious circle. Sextus insists also that arriving to a definite conclusion is not merely a matter of high education, intellectual integrity, wisdom or experience, since it is mostly a matter of the proper nature of the problem. Sextus doctrines have exerted a strong influence on the course of Western philosophy, from the seventeenth century and onwards. The sceptical influx is of substantial importance for the current philosophy of the science, the neurophilosophy, the scientific research, the modern schools of psychology, offering also an essential theoretical background for the evidence based medicine.

The fields of nanotechnology and nanoscience are full of chances and challenges. How to modify the classical continuum mechanics to face out the dramatically novel characteristics and phenomena on mechanical response of nano-materials/structures becomes an ambitious goal pursued by mechanics researchers. The theory of surface elasticity built by Gurtin and Murdoch has been developed to be an important number in theory family of nanomechanics. In this talk, we present an overview of recent advances in application of surface elasticity theory at nanoscale. In particular, we focus on the elastic and plastic deformation, vibration and buckling, fracture and contact behavior of nanoscale solids from one-dimension to three-dimension. We hope this review can provide valuable insight into nanomechanics analysis method with taking surface effect into account, and that the available results in review may lightly bridge the gap between the expression of conventional mechanics and findings of simulation and experiment, after which the practical utilization of nanotechnology in such areas as multifunctional materials and MEMS (Mirco-Electro-Mechanical-System) can be propelled.

A novel and rational approach based on Lie analysis is proposed to investigate the mechanical behavior of materials exhibiting experimental master curves. It relies on the idea that the mechanical response of materials is associated with hidden symmetries; The general objective of this contribution is to reveal those symmetries from measurements and to construct constitutive laws from them. This approach leads to the formulation of constitutive laws from data as well as the possibility of predicting new master curves and material charts; Especially, the time-temperature equivalence principle for polymers is obtained from the requirement of group invariance of the field equations. After an exposition of the general methodology, an application is done to the uniaxial creep and rupture behavior of a Chrome-Molybdene alloy (9Cr1Mo) at different temperatures and stress levels. Constitutive equations for creep and rupture master responses are identified for this alloy and validated on experimental data.

The need for powerful and reliable thermal management systems has increased exponentially in the last two decades in order to sustain the performance of a very wide range of systems. Conventional heat transfer fluids such as water, ethylene glycol, water/ethylene glycol mixtures and lubricating oils are poor heat transfer fluids due to their low thermal conductivity. To overcome this limitation, nanofluids were first developed in 1995 by suspending spherical nanoparticles of metal and metal oxides in heat transfer fluids. It was later observed that these nanofluids showed significant limitations associated with the sphericity and agglomeration of the nanoparticles and lower values of thermal conductivity. Later on in 2001 a new class of nanofluids consisting of colloidal suspensions of carbon nanotubes was developed. Single wall carbon nanotubes have a thermal conductivity in the axial direction up to 6,000W/mK and can be nano engineered into the appropriate nanofluid. This results in carbon nanotube nanofluids with a much higher thermal conductivity then those based on metal and oxide particles, better stability, increased lubricity, good fluidity, non-clogging properties and low chemical reactiveness. The reported values for the thermal conductivity of carbon nanotube nanofluids cover a wide range, depending on the base fluid, nano chemistry, processing routes and temperatures. Typical top range increments can exceed 175% for a 1 vol% load. Higher increments have been achieved at higher loads but with significant increase in the viscosity. The best fluids have good fluidity, no significant settling in stationary mode over a period of several years and no significant separation in dynamic or flowing mode. This paper presents the thermal conductivity of carbon nanotube nanofluids from the nano to the macro scales.

During the rolling process in the aluminum industry, the roll faces, once in a while, some thermal heating or stress. This phenomenon may occur due to some mechanical or technological problems or due to the effect of external materials on the rolling strip. Those can affect some metallurgical defect as phase transformation or mechanical defect such as crack initiation or even spelling on roll surface. These defects, if not properly addressed, can cause heavy damage to the roll and create losses in the rolling process. In such cases, the roll must be changed and the damaged area should be repaired in order to prepare the roll for subsequent work. The roll repairing process is done by heavy grinding that has high cost and also decreases the roll working campaign. So an analyses of the heat flux is important to determine the heat affected area in the cold work forged steel roll which is cause of many accidents. In this paper thermal shock effect on the roll is analyzed by computational mechanics by using ANSYS software and metallurgical evaluation using years of industrial strip rolling experience. The heat affected area that may have some metallurgical phase transformations is also investigated. As a result, the depth of phase transformation of the roll surface due to any thermal shock is investigated and analyzed by finite element method. The obtained results are very useful to rolling industries in order to predict the size and nature of grinding that should be carried out in affected rolls.

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