Browsing by Author "Timothy G. Clapp, Committee Member"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • No Thumbnail Available
    An Inelastic Analysis Methodology for Bonded Joints with Shear Deformable, Anisotropic Adherends
    (2004-02-19) Smeltzer, Stanley S. III; Eric C. Klang, Committee Chair; Timothy G. Clapp, Committee Member; Fuh-Gwo Yuan, Committee Member; Jeffrey W. Eischen, Committee Member
    The development of a one-dimensional analysis method for evaluating adhesively bonded joints composed of anisotropic adherends and adhesives that exhibit nonlinear material behavior is presented. The strain and resulting stress fields in a general, bonded joint overlap are determined by using a variable-step, finite-difference solution algorithm to iteratively solve a system of first-order differential equations. Applied loading is given as a system of combined extensional, bending, and shear loads that are applied to the edge of the joint overlap. Adherends are assumed to behave as linear, cylindrically-bent plates using classical laminated plate theory that includes the effects of first-order transverse shear deformation. This provides a capability for modeling differences in the transverse shear modulus between each adherend. Using a total plasticity theory and a modified von-Mises yield criterion, inelastic material behavior is modeled in the adhesive layer. Results for the proposed method are verified using the single-lap joint geometry against previous results from the literature and shown to be in excellent agreement. Convergence of the strain and stress fields determined using the finite-difference solver are described as a function of the number of evaluation points along the length of the joint. Additionally, design studies using the single-lap joint are presented that investigate the effects of changes to the joint overlap, adherend thickness, laminate stacking sequence of the adherend, adherend material properties, and adhesive material properties. Results from the design studies established a nonlinear relationship between changes in the bending and axial stiffness of the adherends due to laminate ply manipulations and a reduction in the inelastic adhesive strain and shear stress responses. Additionally, analyses performed on the bonded joint models that had a difference in the transverse shear stiffness between the upper and lower adherends displayed a minimal effect on the adhesive strain and stress responses.
  • No Thumbnail Available
    Systematic Approach for Error Proofing Transaction Processes
    (2009-04-23) Sutton, Kristen Ruth; Timothy G. Clapp, Committee Member; C. Thomas Culbreth, Committee Co-Chair; Jeffrey A. Joines, Committee Chair
    The purpose of this research was to develop a model to reduce errors in transactional processes within companies. The model created utilized three error proofing concepts: the FMEA, TRIZ Solution Directions, and the Error Proofing Healthcare (EPH) model. The research involved analyzing 250 FMEA’s that were previously conducted in a large transactional corporation and obtaining feedback from associates. The model that was created consisted of three phases. Phase one identifies the potential failures that could occur within a process while phase two uses TRIZ solution directions to create multiple innovative solutions and phase three uses a method called Solution Priority Number (SPN) to rank and evaluate the solutions generated. The SPN consists of the return on investment (ROI) and the ease of implementation of each solution. Excel worksheets were created to support the Error Proofing Transaction (EPT) model. A case study was performed within a large transactional corporation. A team completed the existing FMEA and then completed the new EPT model. When comparing the existing FMEA and the EPT model it was found that the EPT model reduced the team meeting time by 50% and produced more failure modes, more effects, more causes, more high risk failure modes, as well as a more enhanced set of solutions.