Workability Evaluation of Welding Works Using Virtual Human Model and Kansei Engineering

Abstract

The authors have carried out the human task simulation by a computer about the shipbuilding works in order to increase the productivity and safety so far, corresponding to the recent situation of the Japanese shipbuilding industry; decreasing of skilled workes and increasing of old workers.
This report picked up the welding works for hull construction as a main job in shipbuilding. For the typical welding postures such as flat, horizontal, vertical, and overhead position, the human body analysis has been carried out, using general-purpose human simulation software “Jack”; static strength prediction of human body, lumbar force analysis, and energy consumption analysis. Moreover, the necessary rest time to recover the fatigue has been studied, and the optimal work cycle is examined.
In addition, “Kansei Engineering” technique has been introduced for the evaluation of the results by the biomechanical analysis. SD (Semantic Differential) evaluation has been carried out concerning the body feeling of welding workers, and then principle factor analysis, one of multivariate analysis, has been executed, according to the process of “Kansei Engineering”.
As the result, it can be concluded that the flat position to weld, widely applied posture, is most severe for static load on lower body as well as energy expenditure, and that the rule of “short breaks and often” is preferable from the viewpoint of recovery of the fatigue, especially for the works such that the consumption energy is large. Furthermore, it can be concluded that overhead position to weld is severe in the evaluation of “Kansei Engineering”, because of the fatigue on upper body, and that “the weariness of the hand” causes the working fatigue by the welding works.