Retrofitting ancient timber glulam mortise & tenon construction joints through computer-aided laser cutting

Zhaoxi Zhan; Chen Wang; Jeffrey Boon Hui Yap; Ming Shyang Loi

doi:10.1016/j.heliyon.2020.e03671

Retrofitting ancient timber glulam mortise & tenon construction joints through computer-aided laser cutting

Heliyon. 2020 Apr 11;6(4):e03671. doi: 10.1016/j.heliyon.2020.e03671. eCollection 2020 Apr.

Authors

Zhaoxi Zhan¹, Chen Wang², Jeffrey Boon Hui Yap³, Ming Shyang Loi⁴

Affiliations

¹ College of Civil Engineering, Huaqiao University, 361021, Xiamen, China.
² Director of Intelligence and Automation in Construction Fujian Province Higher-educational Engineering Research Centre, College of Civil Engineering, Huaqiao University, 361021, Xiamen, China.
³ Department of Surveying, Lee Kong Chian Faculty of Engineering and Science, Universiti Tunku Abdul Rahman (UTAR), 43000, Kajang, Selangor, Malaysia.
⁴ Faculty of Built Environment, University of Malaya, 50603, Kuala Lumpur, Malaysia.

Abstract

This study is aimed to rationalise and demonstrate the efficacy of utilising laser cutting technique in the fabrication of glulam mortise & tenon joints in timber frame. Trial-and-error experiments aided by laser cutter were conducted to produce 3D timber mortise & tenon joints models. The two main instruments used were 3D modelling software and the laser cutter TH 1390/6090. Plywood was chosen because it could produce smooth and accurate cut edges whereby the surface could remain crack-free, and it could increase stability due to its laminated nature. Google SketchUp was used for modelling and Laser CAD v7.52 was used to transfer the 3D models to the laser cutter because it is compatible with AI, BMP, PLT, DXF and DST templates. Four models were designed and fabricated in which the trial-and-error experiments proved laser cutting could speed up the manufacturing process with superb quality and high uniformity. Precision laser cutting supports easy automation, produces small heat-affected zone, minimises deformity, relatively quiet and produces low amount of waste. The LaserCAD could not process 3D images directly but needed 2D images to be transferred, so layering and unfolding works were therefore needed. This study revealed a significant potential of rapid manufacturability of mortise & tenon joints with high-quality and high-uniformity through computer-aided laser cutting technique for wide applications in the built environment.

Keywords: Architecture; Civil engineering; Computer-aided engineering; Laser cutter; Materials science; Mortise & tenon joints; Mortise joints; Structural engineering; Tenon joints; Timber frame.