A functional evaluation experiment was carried out in a basic study aimed at evaluating fatigue life without fatigue testing in CO2 arc welded butt joints. Specifically, the S/N ratio of the load and deformation obtained in a tension test and the S/N ratio of the fatigue life obtained from a fatigue test were calculated and compared. The results showed good agreement between the two ratios. In the process of calculating the S/N ratio of the joint stiffness, the appropriate range of signal factors when fatigue strength was the target characteristic was also investigated. In addition, the method of setting the standard condition when the standardized S/N ratio is used was studied, and a proposal was made concerning the method of calculating the S/N ratio of fatigue life in the highcycle region.

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Quality engineering is taught in the curriculum of the Department of Mechanical Engineering at the Aichi Institute of Technology with the aim of training students who will be valuable to manufacturers. As one activity, students were given the problem of maximizing the stable floating time of a familiar and easily made material: confetti chips. When the reports were collected and collated, a range of scatter was found in the optimal shape. The freedom allowed the students in the selection of control factors may have been one cause of the scatter, but the floating characteristics of the confetti may also be involved. As a result, with the purpose of setting the direction for future instruction, an improved method of obtaining stable floating was found, as reported herein. It appears necessary to use educational problems selectively, taking account of the level of difficulty they present to the beginner and the latitude of freedom of design afforded to the individual student.

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