Prediction of Bending Strength of Sugi Medium Dimension Glulam Beams by Monte-Carlo Simulation
Tomoyuki HAYASHI, Naoyuki ITAGAKI, Syoji OGURO, Yasuo NAKAJIMA and Hatsuo MACHIDA
Abstract:Mechanical properties of Sugi (Cryptomeria japonica D. Don) vary with its cultivars and provenance. The variety sometimes results in the difficulties for producing glulams stipulated in Japanese Agricultural Standard (JAS) for structural glued laminated timber. To examine the feasibility of Sugi glulams with arbitrary composition of laminations, eight kinds of full size glulams were produced in a laboratory and a glulam mill without considering the regulation of JAS. Bending tests were conducted and the results were compared with simulated data generated by a Monte-Carlo simulation model using correlated data between modulus of elasticity (MOE) and tensile strength (TS) of laminations. Modulus of rupture (MOR) of laboratory-made glulams was in a range predicted by the simulation model. However, predicted MOR of factory-made glulams did not coincide well with real testing data, because proper correlation data in the factory was not used for the simulation. The Monte-Carlo simulation model was found to be applicable to quality control for the strength of glulams. However, in order to predict the strength distribution more precisely, proper strength data of laminations at each factory should be accumulated and renewed periadically. Key Words:Monte-Carlo simulation, Bending strength, Glulam, Sugi, Fullsize test