Nondestructive evaluation techniques for assessing dynamic modulus of elasticity of moso bamboo (Phyllosachys edulis) lamina

摘要

Bamboo, an extensively used material in Asia, is becoming an increasingly available structural (e.g., flooring and furniture) material in Taiwan. The bending strength and dynamic modulus of elasticity of moso bamboo (Phyllosachys edulis) laminae were investigated using ultrasonic-wave and drilling resistance techniques. The strength quality of bamboo was reduced after steaming treatment and was significantly affected by node characteristics. The transverse variations of the mean drilling resistance value (R) gradually increased outward from the bamboo cavity layer. There were very significant positive relationships among density (ju), the drilling resistance value (R), the dynamic modulus of elasticity (Eb), the modulus of elasticity (MOE), and the modulus of rupture (MOR), although the coefficients of determination were small. Combining ultrasonic-wave and drilling resistance techniques is efficient in estimating and establishing the dynamic modulus of elasticity (REb). Values of REb for moso bamboo increased with increasing ju, R, Eb, MOE, and MOR, and the relationships could each be represented by positive linear regression formulas.