An Investigation of the Fracture of Butt Joints in Parallel-Laminated Veneer

A finite-element analysis and experimental testing program was conducted to investigate the fracture mechanics aspects of butt joints in parallel-laminated veneer (PLV). The effects of the number of plies, ply thickness, and joint spacing were investigated. It was found that the isotropic and orthotropic solutions for edge-cracked specimens were very close. Also, the increase in the stress-intensity factor for the exterior butt joint was of the order of only 4% for a joint separation spacing of four ply-thicknesses. In general, it was found that Mode I fracture toughness increased with decreasing veneer thickness and that the fracture toughness of exterior butt-jointed specimens varied with veneer thickness and number of plies. Results of the butt-joint interaction tests indicate a much higher degree of joint interaction than predicted by the finite-element analysis

Coarsening model of cavity nucleation and thin film delamination from single-crystal BaTiO3 with proton implantation

The layer splitting mechanism of a proton implanted single crystal ferroelectric BaTiO3 thin film layer from its bulk BaTiO3 substrate has been investigated. The single crystal BaTiO3 thin film layer splits as the hydrogen gas diffuses and the internal cavity pressure increases. Ripening mechanism driven by the pressurized hydrogen in the implantation-induced damage zone makes coarsening of the cavities and causes the delamination of the thin layer during the annealing. A unique criterion relation of blister nucleation and evolution has been derived and a simplified debonding criterion is proposed in terms of dimensionless parameters based on the force equilibrium condition. A numerical simulation of two-bubble evolution and delamination of thin film is performed using a finite element method

Flight simulator for hypersonic vehicle and a study of NASP handling qualities

The research goal of the Human-Machine Systems Engineering Group was to study the existing handling quality studies in aircraft with sonic to supersonic speeds and power in order to understand information requirements needed for a hypersonic vehicle flight simulator. This goal falls within the NASA task statements: (1) develop flight simulator for hypersonic vehicle; (2) study NASP handling qualities; and (3) study effects of flexibility on handling qualities and on control system performance. Following the above statement of work, the group has developed three research strategies. These are: (1) to study existing handling quality studies and the associated aircraft and develop flight simulation data characterization; (2) to develop a profile for flight simulation data acquisition based on objective statement no. 1 above; and (3) to develop a simulator and an embedded expert system platform which can be used in handling quality experiments for hypersonic aircraft/flight simulation training

The Effects of Real-Time Individual Performance Feedback and Goal Setting on Computer-Mediated Group Idea Generation

Prior computer-mediated group idea generation research has concluded that social loafing is likely an important factor in reducing individual and group task performance. Group researchers—both focusing on non-technology and technology-mediated groups—have theorized that loafing could be minimized if individuals and groups were given either clear feedback on their task performance or if given clear and attainable performance goals. To examine the efficacy of these interventions on task performance, a computer-mediated idea generation environment was constructed that provided performance feedback for all group members where each member could view how many ideas every group member produced throughout an experimental session. In addition, this environment supported the ability to set a challenging, but attainable, performance goal for each group member (i.e., throughout a session, each member was able to track their performance toward a pre-set performance goal). Using this computer-mediated environment, a laboratory experiment was conducted with five-member groups that examined the influence of both goal setting (i.e., explicit–difficult versus do your best) and performance feedback (i.e., performance feedback versus no-performance feedback) in a 2 × 2 factorial design on group task performance. Providing performance feedback was found to signi- ficantly improve task performance. Additionally, performance feedback and goal setting interacted, such that groups in the performance feedback/explicit–difficult goal treatment had the highest performance. The implica- tions of these results for future research, as well as the implications for the design of the human-computer interface in electronic group idea generation systems, are discussed

Chaminade Musical 1917: \u27W.J. Chaminade: Ein Lebensbild\u27

An oratorio written and first performed to commemorate the 100th anniversary of the foundation of the Society of Mary. Music by Father Francis Joseph Jung, S.M.; text by Father John Winkelbauer, S.M