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This study investigated the Internal State (IS) language input of parents, IS language use by children, and children’s performance on perspective taking and false belief Theory of Mind (ToM) tasks. Two groups of participants were included: children with Autism Spectrum Disorder (ASD) (N = 12, M chronological age = 7; 4, M language age = 6;0) and typically-developing (TD) children (N = 13, M chronological age = 6;0, M language age= 6;5), matched on language age. Independent means samples t-tests showed that the transcripts of the two groups of parents or the two groups of children did not differ in regards to total number of words, utterances, or mean length of utterance. ANOVAs were used to test for differences in IS language category or elaboration in the two groups (ASD, TD), in parents and children. For the parent data, no statistically significant differences emerged. For the analysis of child talk the ANOVA revealed that the main effect of group approached significance, with a trend towards TD children using more IS language than children with ASD. ANOVAs were also used to test for differences in ToM task performance (perspective-taking, false belief) in the two groups of children; TD children performed significantly better on ToM Tasks overall than the children with ASD. Partial correlations found that for the TD group, there were no significant correlations between the parent’s or the child’s use of IS language with the child’s performance on ToM tasks when chronological age was controlled for. For the ASD group, after controlling for chronological age and language age, the parent’s use of elaborated affect terms was significantly positively correlated with their child’s performance score on perspective-taking tasks, and the parent’s use of elaborated cognitive terms was significantly negatively correlated with their child’s performance on false-belief tasks. Also for the ASD group, the child’s use of simple affect terms was significantly positively correlated with their performance on false belief tasks after controlling for chronological age and language age. Findings are discussed in relation to prior research and clinical implications.

In this study, a new consistent formulation coupling kinematics, thermodynamics, and kinetics with damage using an extended multiplicative decomposition of the deformation gradient that accounts for corrosion effects is presented. The technical approach used for modeling the corrosion behavior of magnesium alloys was divided into three primary steps. First, a predictive corrosion model was developed based on experimental corrosion observations. The experimentally-observed corrosion mechanisms of pitting, intergranular, and general corrosion on the AZ31 magnesium alloy were quantified in 3.5 wt.% NaCl immersion and salt spray environments using optical microscopy and laser profilometry to document the changes in the pit characteristics. Although both environments showed similar trends, the immersion environment was more deleterious with respect to intergranular and general corrosion. On the other hand, the salt-spray environment allowed deeper pits to form throughout the entirety of the experiments, which led to a substantial thickness drop (general corrosion) compared with the immersion environment. Next, the complete corrosion model based upon the internal state variable theory was formulated to capture the effects of pit nucleation, pit growth, pit coalescence, and general corrosion. Different rate equations were given for each mechanism. Following the formulation of the model, the aforementioned experimental work and experimental work on four other magnesium alloys (AZ61, AM30, AM60, and AE44), was used to validate the model.

This dissertation proposes a multiscale Internal State Variable (ISV) inelasticity-corrosion damage model that is motivated by experimental microstructure-property relations of magnesium alloys. The corrosion damage framework was laid out based on observation of different corrosion mechanisms occurred on an extruded AM30 magnesium alloys. The extruded AM30 magnesium alloy was studied under two corrosion environments (cyclical salt spray and immersion) in order to observe the corrosion rates under different exposure environments. The coupons were examined at various times to determine the history effects of three corrosion mechanisms: (1) general corrosion; (2) pitting corrosion in terms of the nucleation rate, growth rate, and coalescence rate; and (3) intergranular corrosion. The multiscale ISV corrosion model was developed by bridging the macroscale corrosion damage to the mesoscale electrochemical kinetics, microscale material features, and nanoscale material activation energies. The corrosion testing results of Mg alloys (pure Mg, Mg-2% Al, and Mg-6% Al) were used to develop, calibrate, and validate the model, and good agreement was found between the model results and the corrosion testing data. Finally, the simultaneous effects of corrosion and cyclic loading were tested but not modelled for the extruded AM30 magnesium alloy by conducting fatigue experiments in a 3.5 wt.% NaCl solution environment. The corrosion fatigue life of the AM30 alloy was significantly reduced due to corrosion pit formation on specimen surface, hydrogen diffused into the material , and the fracture surface dissolved into the solution. The corrosion damage that arose on the fatigue specimens reduced the crack nucleation process and enhanced the crack propagation rate.

This work presents a combined theoretical-experimental study of strain rate behavior in metals. The method is to experimentally calibrate and validate an Internal State Variable (ISV) constitutive model with a wide range of strain rate sensitivity. Therefore a practical apparatus and methodology for performing highly sought-after intermediate strain rate experimentation was created. For the first time in reported literature, the structure-property relations of Rolled Homogeneous Armor is quantified at the microscale and modeled with varying strain rates, temperatures, and stress states to capture plasticity and damage with a single set of constants that includes intermediate strain rates. A rolled homogeneous armor (RHA) was used as a material system to prove the methodology. In doing so, a newly implemented strain rate dependent nucleation parameter for RHA was implemented to transition the dominant damage mechanism from void growth to void nucleation as strain rate increased. The ISVs were utilized in finite element analysis for robust predictability of mechanical performance as well as predictability of microstructural evolution with regards to void size and number distribution. For intermediate strain rate experiments, robust load acquisition was achieved using a novel serpentine transmittal bar that allowed for long stress waves to traverse a short bar system; this system eliminated load- ringing that plagues servo-hydraulic systems. A direct hydraulic loading apparatus was developed to provide uniform strain rates throughout intermediate rate tests to improve on the current limitations of the state-of-the-art. Key recommendations on the advancement of predictive modeling of dynamic materials, as well as performing advanced dynamic experimentation, are elucidated.

In the current study we developed an internal state variable (ISV) model based on the Bammann inelasticity internal state variable model (BIISV) to include damage, recrystallization, and texture development, which we then implemented into a mantle convection code, TERRA2D, to incorporate higher fidelity material behavior into mantle convection simulations. With experimental stress strain data found in the literature model constants for the BIISV model were determined for a number of geologic materials. The BIISV model was shown to be far superior to the steady state power law model currently used by the geologic community to capture the deformation of geologic materials. Once implemented and verified in TERRA2D the BIISV model revealed locations of hardened material that behaved like diverters in the cold thermal boundary layer that the power law model could never produce. These hardened regions could be a plausible reason for the current subduction zones present on the earth. We then altered the BIISV model equation to include the effects of damage, recrystallization, and texture development in order to model possible weakening mechanisms in the cold thermal boundary layer of the mantle. Inclusion of damage and recrystallization allowed the cold thermal boundary layer to mobilize and plunge downward into the hotter region below. Texture development increased the intensity of rotational flow within the hotter zone as cold boundary material plunged downward which aided in destabilizing the cold upper thermal boundary layer. The inclusion of an internal state variable model with damage, recrystallization, and texture development represents a significant advancement in handling deformational physics for mantle phenomena in a comprehensive, unified, and automatic manner.

A macroscale Internal State Variable (ISV) constitutive model coupling magnetism effects with thermal, elastic, and damage effects is developed. Previous models for magnetic and mechanical fields included constitutive equations describing their effects on the material system studied independently. Some models explain the mechanisms behind mechanical deformations caused by magnetization changes that are presented in the literature. They mainly focus on the nanoscale level. Other models, describe the behavior of one specific magnet that is mostly a permanent magnet. However permanent magnets are made of rare-earth elements that are subjected to a high supply risk. In attempt to find an alternative to permanent magnets, a mathematical model that captures the physical behavior of magnets is needed, to help develop a tool to create a new permanent magnet. The ISV constitutive model herein describes the macroscale mechanical deformation caused by magnetic fields on ferromagnetic materials, Iron (Fe), Cobalt (Co) and Nickel (Ni) precisely. The ISV model internally coheres the kinematic, thermodynamic, and kinetic relationships of deformation using the evolving histories of internal variables. For the kinematics, a multiplicative decomposition of deformation gradient is employed including a magnetization term, and the Jacobian that represents the conservation of mass and conservation of momentum. The First and Second Law of Thermodynamics are used to constrain the appropriate constitutive relations through the Clausius-Duhem inequality. The kinetic framework employs a stress-strain relationship with a flow rule that couples the thermal, mechanical, and damage terms. To determine the ISVs needed to mimic the behavior of magnetic materials, we conducted various magnetic experiments on three different specimens made of Iron, Nickel and Cobalt. Experiments captured the mechanical deformation of a rod sample when subjected to a magnetic field using the Michelson Interferometer. To study the magnetic hysteresis of Iron, Nickel, and Cobalt, previous literature data were used. It was shown that the magnetization equation modeled the hysteresis of Iron, Nickel, and Cobalt. The magnetostrictive strain equation shows good agreement for Nickel and Cobalt, but further investigation should be done for Iron.

This dissertation proposes a modi ed internal state variable (ISV) inelastic damage model that was motivated by experimental structure{property relations of thermoplastics. In particular, a new damage model was developed for glassy, amorphous thermoplastics. ISV evolution equations are de ned through thermodynamics, kinematics, and kinetics for isotropic damage arising from two di erent inclusion types: pores and particles. The damage arising from the particles and crazes is accounted for by three processes: damage nucleation, growth, and coalescence. Damage nucleation is de ned as the number density of voids/crazes. The associated ISV rate equation is a function of stress state, molecular weight, fracture toughness, particle size, particle volume fraction, temperature, and strain rate. The damage growth is based upon a single void growing and its growth is de ned by an ISV rate equation that is a function of stress state, strain rate sensitivity, and strain rate. The coalescence ISV equation enables interaction between voids and crazes and is a function of the nearest neighbor distance between voids/crazes, size of voids/crazes, temperature, and strain rate. The damage arising from pre-existing voids employs the Cocks{Ashby void growth rule. The total void volume fraction is a summation of the damage arising from particles, pores, and crazes. Micromechanical modeling results for a single void compare well to experimental ndings garnered from the literature. This formulation is then implemented into a nite element analysis. For damage evolution, comparisons are made between a one-dimensional material point simulator and a three-dimensional nite element (FE) simulation. Finally, good agreement is found between impact experiments and FE impact simulations using the implemented model.

Les systèmes de robotique sociale sont de plus en plus présents dans nos vies. Ce ne sont plus des entités isolées, mais on s'attend à ce qu'ils soient capables d'interagir et de communiquer avec les humains. Ils doivent respecter les normes comportementales attendues par les humains avec qui les systèmes robotiques sont en interaction.L'une des principales pistes de recherche dans le domaine de la robotique sociale est représentée par la conception d'une interaction naturelle entre un robot social et un individu. Plus spécifiquement, cette interaction devrait prendre en considération le profil de l'individu, l'état émotionnel, l'état physiologique et l'humeur, entre autres.Dans cette thèse, nous explorons la relation qui existe entre l'échelle de typologie circadienne, la performance cognitive et l'état physiologique au cours de différents scénarios d'interaction homme-robot. L'administration de différents questionnaires psychologiques permet de déterminer le profil d'un individu. En outre, à l’aide de différents capteurs (par exemple, GSR, caméra thermique), de multiples méthodologies ont été développées pour déterminer l’état physiologique d’un individu. Plus spécifiquement, la variation de la température faciale, le clignotement des yeux et la réponse galvanique de la peau ont été étudiés.Plusieurs scénarios d'interaction homme-robot ont été conçus afin de tester le système développé. L'impact de l'empathie a également été étudié. En outre, le système développé a été testé avec succès dans deux environnements réels, avec deux populations vulnérables. La première application d'assistance est représentée par le projet de recherche EU H2020 ENRICHME, dans lequel un robot a été développé pour les personnes âgées atteintes d'un trouble cognitif léger. La deuxième population vulnérable est constituée d'individus souffrant de différents troubles du sommeil.Nous pensons que cette thèse représente une étape importante dans la compréhension de l'état physiologique de l'individu et est liée à la performance cognitive. / Social robotic systems are more and more present in our everyday lives. They are no longer isolated entities, but instead, they are expected to be capable of interacting and communicating with humans. They have to follow the behavioral norms that are expected by the individuals the robotic systems are interacting with.One of the main research directions in the field of social robotics is represented by the design of a natural interaction between a social robot and an individual. More specifically, this interaction should take into consideration the profile of the individual, the emotional state, the physiological internal state, and the mood, among others.In this thesis it is explored the relationship that exists between morningness-eveningness, cognitive performance, and the internal physiological state during different human-robot interaction scenarios. By administering different psychological questionnaires, the profile of an individual can be determined. Moreover, with the help of different sensors (e.g., GSR, thermal camera), multiple methodologies were developed to determine the internal physiological state of an individual. More specifically, the facial temperature variation, the blinking, and the galvanic skin response were investigated.Several human-robot interaction scenarios have been designed in order to test the developed system. The impact of empathy was also investigated. Furthermore, the developed system was successfully tested in two real-world environments, with two vulnerable populations. The first assistive application is represented by the ENRICHME EU H2020 research project, where a personal robot was developed for the elderly with mild cognitive impairment. The second vulnerable population consists of individuals suffering from different sleep disorders.We believe that this thesis represents an important step in understanding how the physiological internal state of an individual is related to cognitive performance, and to the user profile of that individual.

The objective of this work is to develop an evolution equation for the ductile growth of a spherical void in a highly strain rate and temperature dependent material. The material considered in this work is stainless steel 304L at 982 °C. The material is characterized by a physically-based internal state variable model derived within consistent kinematics and thermodynamics — Evolving Microstructure Model for Inelasticity. Through this formulation, the degradation of the elastic moduli due to damage has been naturally acquired. An elastoviscoplasticity user material subroutine has also been developed and implemented into a commercially available finite element software ABAQUS. The subroutine utilizes a return mapping algorithm, where a purely elastic trial state (elastic predictor) is followed by a plastic corrector phase (return mapping). A conditionally stable fully-implicit scheme, derived from the backward Euler integration method, has been employed to calculate the values of the internal state variables in the elastoviscoplasticity integration routine. A repeating unit cell problem is set up by introducing a spherical void inside a matrix material that simulates a periodic array of voids in a component. Using finite element analysis, a database is generated by recording the responses of the unit cell under various combinations of loading conditions, porosity, and state variables. Functional forms of the void growth equations are constructed by utilizing normalization techniques to collapse all the data into master curves. The evolution equations are converted to a form consistent with the continuum damage variable in the complete thermal-elastic-plastic-damage version of the physically-based internal state variable model.