Designing method for Japanese traditional joinery based on cluster boundaries defined by weighted spectral clustering and its application to mechanical joint design

Abstract

Environmentally friendly design is becoming one of the major concerns in product design due to the growing impact of global warming and the pursuit of carbon neutrality. The ‘Tsugite’, observed in historical buildings in Japan, is a traditional joinery technique designed to enable the replacement of worn parts to extend the life of temples and pagodas. It is an inherently sustainable technique. In this paper, a new joint design method, based on the concepts of the ‘Tsugite’, is proposed. This method aims to enable the replacement of parts for frame-structured automobiles. Weighted spectral clustering is selected to design the joint, as a characteristic of the minimum-cut of spectral clustering is suitable for guiding and designing matching surfaces of the ‘Tsugite’ joinery. To apply this method to more complexly shaped mechanical joints, a coordinate transformation based on the principal axes of the stress tensor is introduced. By selecting the shear stress in the plane defined by the two maximum principal axes of the stress tensor as weights for clustering, appropriate clustering results can be obtained. The boundaries of clusters provide good guidance for designers to design mechanical joints for frame structures.

Keywords

• tsugite
• japanese joinery
• frame structure
• spectral clustering
• finite element analysis