Bending Performance of Structural Glued Laminated Timber Laminae from Chinese Fir Plantation
In this paper,the laminae from Chinese fir plantation(Cunninghamia lanceolata)were studied.The effects of three types of finger length and four types of Chimerism on the bending properties of Chinese fir finger-joint laminae were analyzed.The bending properties of different grades of Chinese fir finger-joint and nonfinger-joint laminae were obtained.And the correlated mathematical equation of the bending properties were established.The results showed that finger length and chimeric degree had a great influence on the bending properties of finger-joint laminae.Under the experimental conditions,the optimal process for the finger-joint laminae from plantation Chinese Fir were:finger length 15 mm,width to distance ratio 0.18,chimeric degree 0.1 mm.Grading had a great influence on the bending properties of finger-joint and nonfinger-joint laminae.The characteristic values of bending strength of grade Ⅰ and grade Ⅱ finger-joint laminae were 28.7 MPa and 26.6 MPa,respectively.They were 17.14％and 8.57％higher than those of nongraded Chinese fir finger-joint laminae,respectively.The dynamic elastic modulus and static elastic modulus based on the stress wave method,static elastic modulus,and bending strength of Chinese fir laminae were significantly positive correlated.The correlation coefficient was 0.838 and 0.691,respectively.
Chinese firstructural glued laminated timberlaminaefinger-joint processmachine gradingbending properties
国家科技期刊平台
NSTL
万方数据
维普
