G. Odegard | Michigan Technological University (original) (raw)

Papers by G. Odegard

2016 ASEE Annual Conference & Exposition Proceedings

followed by a MSc and PhD in Engineering Systems (Civil, Mechanical and Electrical Engineering hy... more followed by a MSc and PhD in Engineering Systems (Civil, Mechanical and Electrical Engineering hybrid) from the Colorado School of Mines. He started at Michigan Technological University in Fall 2012 as a lecturer in Mechanical Engineering and has been focused on teaching junior and senior engineering design classes as well as educational and curriculum development. He is coordinator of the first new ME-Practice course in the revised Mechanical Engineering curriculum and faculty advisor of the Mining INnovation Enterprise.

2014 ASEE Annual Conference & Exposition Proceedings

is an associate professor of Mechanical Engineering at Michigan Technological University. She tea... more is an associate professor of Mechanical Engineering at Michigan Technological University. She teaches classes on manufacturing and does research in engineering education with particular interest in hands-on ability, lifelong learning, and project-based learning.

Molecular modeling techniques are used to predict constitutive behavior of polycarbonate material... more Molecular modeling techniques are used to predict constitutive behavior of polycarbonate material. A polydisperse molecular model with a total of 50 chains is developed with an average of 5.22 monomers per chain and a polydispersity index of 2.17. The predicted mechanical properties are much lower than the experimentally-obtained values, which is a consequence of small number of monomers per chain and of the statistically low number of samples of molecular configurations considered.

The multiscale modeling of polymer-based materials has many challenges that not yet been fully ad... more The multiscale modeling of polymer-based materials has many challenges that not yet been fully addressed in the literature. These challenges are summarized and discussed. A particular challenge is the modeling of the large distribution of microstates that exist in many bulk engineering polymer materials. A multiscale modeling approach is proposed to predict the bulk Young's modulus of polymers using a series of molecular models of individual polymer microstates and a statistics-based micromechanical modeling method. The method is applied to polyimide and polycarbonate material systems.

Journal of Materials Science: Materials in Medicine, 2011

The mechanical properties of collagenous tissues, such as tendon and ligaments, are of particular... more The mechanical properties of collagenous tissues, such as tendon and ligaments, are of particular interest as they are found extensively in the human body. In the present study the transverse mechanical properties of collagen fibers are reported for the first time. The elastic modulus was found to be 63 ± 4 MPa, while the viscosity was estimated to be 14 GPa g 56 GPa s. Comparison with similar data in the literature, for bulk tendon and collagen fibrils, suggests that the apparent modulus of a network of interconnected building blocks is reduced as compared to the modulus of the individual building blocks; in particular E tendon \ E fiber \ E fibril ; this is due to the fact that as the scale of the microstructure increases (i) slippage and sliding between the respective building blocks (fibrils or fibers) increases, (ii) the volume fraction of the stiff collagen proteins decreases.

Journal of Applied Physics, 2010

A nanocomposite electrical generator composed of an array of zinc oxide nanowires is considered. ... more A nanocomposite electrical generator composed of an array of zinc oxide nanowires is considered. The electric potential distribution along zinc oxide nanowires is modeled using continuum mechanics and Maxwell's equations for the case of axial loading. A perturbation technique is used for decoupling the constitutive equations. The governing differential equations are solved using a finite difference method. It is shown that a gradient of electric potential exists along the axis of the zinc oxide nanowires. Maximum and minimum values of electric potential exist at the extreme ends along the nanowire length and have opposite signs. The positive and negative voltages are separated by a zero-valued electric potential at the middle of the nanowire. It is also shown that the electric potential is a strong function of shear stress at the interface of matrix-nanowire. The proposed system and loading configuration can generate up to 160% more electric potential than the values reported for the nanowire in the bended configuration, which results in a more sustainable energy source.

Public reporting burden for this collection of information is estimated to average 1 hour per res... more Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searc, the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including sugges

American Society for Composites 2021

The prediction of thermo-mechanical properties of a thermoset resin at different stages of cure i... more The prediction of thermo-mechanical properties of a thermoset resin at different stages of cure is a complex process. An Integrated Computational Material Engineering (ICME) approach is used to predict the properties of a EPON828/Jeffamine D230 system. The proposed framework integrates two length scales - nano and microscale. Molecular Dynamics (MD) is used to predict the volume shrinkage and mechanical properties of the epoxy resin as a function of the progressing crosslink density at room temperature using the Reactive Interface forcefield (IFF-R). The predicted resin properties show good agreement with the literature, proving that IFF-R can be reliably used for this purpose. Once characterized, the predicted properties are used to further predict the effects of cure shrinkage and property transformation on the bulk-level composite residual stresses. P. P. DESHPANDE

Nanomaterials

Huntsman–Merrimack MIRALON® carbon nanotubes (CNTs) are a novel, highly entangled, commercially a... more Huntsman–Merrimack MIRALON® carbon nanotubes (CNTs) are a novel, highly entangled, commercially available, and scalable format of nanotubes. As-received and acid-treated CNTs were added to aerospace grade epoxy (CYCOM® 977-3), and the composites were characterized. The epoxy resin is expected to infiltrate the network of the CNTs and could improve mechanical properties. Epoxy composites were tested for flexural and viscoelastic properties and the as-received and acid treated CNTs were characterized using Field-Emission Scanning and Transmission Electron Microscopy, X-Ray Photoelectron Spectroscopy, and Thermogravimetric Analysis. Composites containing 0.4 wt% as-received CNTs showed an increase in flexural strength, from 136.9 MPa for neat epoxy to 147.5 MPa. In addition, the flexural modulus increased from 3.88 GPa for the neat epoxy to 4.24 GPa and 4.49 GPa for the 2.0 wt% and 3.0 wt% as-received CNT/epoxy composites, respectively. FE-SEM micrographs indicated good dispersion of t...

Polymers

The impact on the mechanical properties of an epoxy resin reinforced with pristine graphene nanop... more The impact on the mechanical properties of an epoxy resin reinforced with pristine graphene nanoplatelets (GNP), highly concentrated graphene oxide (GO), and functionalized graphene oxide (FGO) has been investigated in this study. Molecular dynamics (MD) using a reactive force field (ReaxFF) has been employed in predicting the effective mechanical properties of the interphase region of the three nanocomposite materials at the nanoscale level. A systematic computational approach to simulate the reinforcing nanoplatelets and probe their influence on the mechanical properties of the epoxy matrix is established. The modeling results indicate a significant degradation of the in-plane elastic Young’s (decreased by ~89%) and shear (decreased by ~72.5%) moduli of the nanocomposite when introducing large amounts of oxygen and functional groups to the robust sp2 structure of the GNP. However, the wrinkled morphology of GO and FGO improves the nanoplatelet-matrix interlocking mechanism, which ...

In this study, a technique has been proposed for developing constitutive models for polymer compo... more In this study, a technique has been proposed for developing constitutive models for polymer composite systems reinforced with single-walled carbon nanotubes (SWNT). Since the polymer molecules are on the same size scale as the nanotubes, the interaction at the polymer/nanotube interface is highly dependent on the local molecular structure and bonding. At these small length scales, the lattice structures of the nanotube and polymer chains cannot be considered continuous, and the bulk mechanical properties of the SWNT/polymer composites can no longer be determined through traditional micromechanical approaches that are formulated using continuum mechanics. It is proposed herein that the nanotube, the local polymer near the nanotube, and the nanotube/polymer interface can be modeled as an effective continuum fiber using an equivalentcontinuum modeling method. The effective fiber retains the local molecular structure and bonding information and serves as a means for incorporating micromechanical analyses for the prediction of bulk mechanical properties of SWNT/polymer composites with various nanotube sizes and orientations. As an example, the proposed approach is used for the constitutive modeling of two SWNT/polyethylene composite systems, one with continuous and aligned SWNT and the other with discontinuous and randomly aligned nanotubes.

47th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference<BR> 14th AIAA/ASME/AHS Adaptive Structures Conference<BR> 7th, 2006

A multiscale constitutive modeling approach has used to model a high-performance polyimide system... more A multiscale constitutive modeling approach has used to model a high-performance polyimide system over a series of temperatures ranging from cryogenic to elevated (approaching the glass transition temperature). The multiscale model has employed computational chemistry techniques to determine the molecular structure and to prescribe deformations for establishing mechanical properties. The resulting predicted mechanical properties have been compared to experimentally-obtain properties for the same polyimide system. The predicted and experimentally-obtained moduli show good agreement in terms of magnitude. However, the predicted moduli did not show the expected temperaturedependence. This discrepancy in the modeling is likely due to the use of harmonic potentials in the force field.

52nd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, 2011

Molecular Dynamics simulations are used to study cross-linking of an epoxy polymer. OPLS force fi... more Molecular Dynamics simulations are used to study cross-linking of an epoxy polymer. OPLS force field parameters are used for modeling a 2:1 stoichiometric mixture of epoxy resin and the cross-linking agent. The model has 17,928 united atoms and a static cross-linking method is used along with molecular minimization and molecular dynamics techniques to achieve two different cross-link densities. The crosslinked models can be used for understanding various phenomenon occurring in cross-linked epoxy resins at the atomic scale. Glass-transition temperature ranges of two differently cross-linked samples have been predicted using the models. These models will be used for studying aging behavior at the atomic level in epoxy materials and understanding the influence of aging on mechanical properties. I. Introduction poxy Resins are prime constituents in adhesives, sealants, and aircraft composite structural components. A wide range of studies have focused on epoxy-based materials to establish physical and mechanical properties. 1-3 The excellent specific-stiffness and specific-strength properties of epoxy-based composite materials are due to the complex microstructure of their constituent materials. There is significant interest in understanding the aging response of these material systems due to their widespread use in commercial aircraft. A. Computational Studies on Epoxy Polymers Epoxy resins are formed when epoxy monomers react with compounds known as cross-linking or curing agents with active hydrogens such as amines and anhydrides. 4 A trial-and-error approach to experimentally optimize the processing conditions of epoxy materials can become time-consuming and expensive. With the advancement of computational technology, computational modeling has provided an efficient route to study these polymer resins. 5-14,4,15 Molecular dynamics (MD) simulations based on the bead-spring model 10,11 and Monte-Carlo simulations based on the bond-fluctuation model 16,8,9 have been used in the last two decades for studying epoxy materials. The beadspring models did not take into account the details of the molecular structures and thus cannot predict the influence of specific groups of atoms on the physical properties. In the last few years, MD at the atomic scale has been quite successful in exploring different phenomena occurring at pico-to nano-second time scales in epoxy resins. 14 Many researchers have studied the formation of cross-linked epoxy resins using different approaches of simulated cross-linking. Doherty et al. 5 modeled PMA networks using lattice-based simulations in a polymerization MD scheme. Yarovsky and Evans 15 discussed a cross-linking technique which they used to crosslink low molecularweight, water-soluble, phosphate-modified epoxy resins (CYMEL 1158). The cross-linking reactions were carried out simultaneously (static cross-linking process). Dynamic cross-linking of epoxy resins was performed by Xu et al. 4

46th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, 2005

The effect of force field type on the predicted elastic properties of a polyimide is examined usi... more The effect of force field type on the predicted elastic properties of a polyimide is examined using a multiscale modeling technique. Molecular Dynamics simulations are used to predict the atomic structure and elastic properties of the polymer by subjecting a representative volume element of the material to bulk and shear finite deformations. The elastic properties of the polyimide are determined using three force fields: AMBER, OPLS-AA, and MM3. The predicted values of Young's modulus and shear modulus of the polyimide are compared with experimental values. The results indicate that the mechanical properties of the polyimide predicted with the OPLS-AA force field most closely matched those from experiment. The results also indicate that while the complexity of the force field does not have a significant effect on the accuracy of predicted properties, small differences in the force constants and the functional form of individual terms in the force fields determine the accuracy of the force field in predicting the elastic properties of the polyimide.

A constitutive model has been developed to predict the elastic response of two dimensional balsa ... more A constitutive model has been developed to predict the elastic response of two dimensional balsa wood material with a distribution of cell geometries. Two planar triangular grids, each assumed to represent the structural network of an open cell foam material, are superimposed to model an overall cellular structure with a distribution of cell geometries. The elastic mixture theory is applied in conjunction with the micropolar elasticity theory to homogenize the cellular structure and to establish the overall constitutive relationship.

Polymeric particles with controlled internal molecular architectures play an important role as co... more Polymeric particles with controlled internal molecular architectures play an important role as constituents in many composite materials for a number of emerging applications. In this study, classical molecular dynamics techniques are employed to predict the effect of chain architecture on the compression behavior of nanoscale polyethylene particles subjected to simulated flat-punch testing. Cross-linked, branched, and linear polyethylene chain architectures are each studied in the simulations. Results indicate that chain architecture has a significant influence on the mechanical properties of polyethylene nanoparticles, with the network configuration exhibiting higher compressive strengths than the branched and linear architectures. These findings are verified with simulations of bulk polyethylene. The compressive stress versus strain profiles of particles show four distinct regimes, differing with that of experimental micron-sized particles. The results of this study indicate that the mechanical response of polyethylene nanoparticles can be custom-tailored for specific applications by changing the molecular architecture.

Microscopy and Microanalysis, 2014

Vanadium dioxide (VO 2), one the correlated electron material has received many attentions throug... more Vanadium dioxide (VO 2), one the correlated electron material has received many attentions through a metal-insulator transition (MIT) at ~ 340 K, close to room temperature [1]. The MIT in VO 2 is associated with a structural phase transition, sharp resistivity and optical transparency changes by several order of magnitudes [2]. The phase transition occurs from a monoclinic (M) structure to a tetragonal rutile (R) structure. The unique properties of MIT in VO 2 have proposed many applications such as thermo/electrochromics, Mott transistors, memristors, thermal actuators, gas sensors, strain sensors and temperature sensors.