Search Constraints

Start Over
Filtering by: Creator Nairn, J. A. Remove constraint Creator: Nairn, J. A.

Search Results

  • Direct coupling of imaging to morphology-based numerical modeling as a tool for mechanics analysis of wood plastic composites

    Creator:
    Lin, Xiang
    Abstract:
    Polymeric composites reinforced with bio-materials have advantages over composites with synthetic reinforcements. Bio-based composites use low-cost and renewable reinforcements, have nonabrasive properties for machining, have improved damping characteristics, and have potential for energy recycling. However, the limited use of bio-based composites is because their mechanical properties are typically much lower...
    Resource Type:
    Masters Thesis
    Full Text:
    Matthew J. Schwarzkopf assisted with experimental data collection. Dr. John A. Nairn was involved with

  • Aspect Ratio Requirements for Nanotube-Reinforced, Polymer-Matrix Composites

    Creator:
    Nairn, J. A.
    Abstract:
    A fiber’s efficiency in a short-fiber composite can be accurately solved by shear-lag methods, which can account for fiber geometry, an imperfect interface (or interphase), and extend to low volume fractions. Such an analysis was used to evaluate the aspect ratio requirements for single-walled nanotubes (SWNT) in a polymeric composite...
    Resource Type:
    Article
    Full Text:
    , 2nd Edition, Kluwer Academic Publishers, 2002. [3] J. A. Nairn, On the use of shear-lag methods for

  • Fracture properties of balsa wood and balsa core sandwich composites

    Creator:
    Shir Mohammadi, Meisam
    Abstract:
    Favorable properties of Balsa wood make it an interesting alternative in a number of applications including thermal insulation or as a lightweight core material in sandwich composites. Increasing use in construction necessitates a better understanding of its mechanical and failure properties. In the present work, mode I and mode II...
    Resource Type:
    Masters Thesis
    Full Text:
    Balsa Wood and Balsa Core Sandwich Composites Abstract approved: John A. Nairn Favorable properties of

  • Determining fracture toughness by orthogonal cutting of polyethylene and wood-polyethylene composites

    Creator:
    Semrick, Kalin
    Abstract:
    The purpose of this thesis was to evaluate orthogonal cutting as a method to determine the fracture toughness of low and high density polyethylene and wood plastic composites. A test fixture was developed to capture normal and tangential cutting forces at variable depth and rake angle. A tool interface method...
    Resource Type:
    Masters Thesis
    Full Text:
    Orthogonal Cutting of Polyethylene and Wood-Polyethylene Composites Abstract approved: John A. Nairn The

  • A numerical study of the transverse modulus of wood as a function of grain orientation and properties

    Creator:
    Nairn, John A.
    Abstract:
    Finite element analysis was used to study the effective transverse modulus of solid wood for all possible end-grain patterns. The calculations accounted for cylindrical anisotropy of wood within rectangular specimens and explicitly modeled wood as a composite of earlywood and latewood. The effective modulus was significantly reduced by growth ring...
    Resource Type:
    Article
    Full Text:
    properties John A. Nairn* Wood Science & Engineering, Oregon State University, Corvallis, OR, USA

  • Further Development of MPM and its Applications in Modeling Wood-Adhesive Bonds

    Creator:
    Hammerquist, Chad C.
    Abstract:
    This work is a culmination of a series of published works related to the use of the Material Point Method (MPM) in modeling wood adhesive bonds. The use of wood as construction material has the potential to play a small role in the solution to the current CO2 and climate...
    Resource Type:
    Dissertation
    Full Text:
    Abstract approved: John A. Nairn This work is a culmination of a series of published works related to the

  • Numerical Simulation of Orthogonal Cutting Using the Material Point Method

    Creator:
    Nairn, John A.
    Abstract:
    A material point method simulation of orthogonal cutting that can simulate cutting into steady-state chip curling is described. The modeling used ductile fracture mechanics using cohesive zone in the cutting path. Robust simulations required a new mechanism to damp kinetic energy artifacts associated with dynamic crack propagation. The simulations displayed...
    Resource Type:
    Article
    Full Text:
    . [13] J. A. Nairn, Modeling of imperfect interfaces in the material point method using multimaterial

  • Generalized crack closure analysis for elements with arbitrarily-placed side nodes and consistent nodal forces

    Creator:
    Nairn, John A.
    Abstract:
    A new approach was developed for the evaluation of energy release rate by the virtual crack closure technique in quadratic and linear elements. The generalized method allows arbitrary placement of the side nodes for quadratic elements and thus includes both standard elements, with mid-side nodes, and singularity elements, with quarter-point...
    Resource Type:
    Article
    Full Text:
    Arbitrarily-Placed Side Nodes and Consistent Nodal Forces John A. Nairn Received: 30 March 2011 / Accepted

  • Elucidating the Mechanism of CNF Reinforcement in Wood Adhesives and Composites

    Creator:
    Munoz Torres, Maria A.
    Abstract:
    In the search to improve and incorporate nano and renewable materials into urea-formaldehyde (UF), several researchers have incorporated cellulose nano fibrillated (CNF) into the adhesive. This study aimed to find an optimal way of incorporating CNF into UF and understand how CNF interacts with and changes the properties of the...
    Resource Type:
    Masters Thesis
    Full Text:
    . CONTRIBUTION OF AUTHORS Dr. John Simonsen and Dr. John A. Nairn materialized the ideas behind the research

  • The effect of elevated temperature on mechanical behavior of structural wood and wood-based composites

    Creator:
    Sinha, Arijit
    Abstract:
    Engineers, in practice, are often faced with the challenge of evaluating a fire-damaged structure and developing a rehabilitation and retrofit plan. In order to decide on a rehabilitation and retrofit plan, information on thermal degradation of building materials and connections are vital. A critical knowledge gap exists in terms of...
    Resource Type:
    Dissertation
    Full Text:
    : ____________________________________________________________________ John A. Nairn Rakesh Gupta Engineers, in practice