Yunnan Dendrocalamus sinicus Chia et J. L. Sun (YDS) is a giant bamboo species with a diameter at breast height of up to nearly 40 cm. It is endemic to Yunnan, China, and only a very small portion of it is directly used as load-bearing beams and columns in the dwellings of ethnic minorities, such as in Dai architecture. Due to the structural characteristics of its hollow and thin walls, systematic physical and mechanical property testing of this species faces significant challenges in terms of methods and means. This issue has become one of the main barriers to the realization of its large-scale industrial use. Therefore, this paper systematically tests and studies YDS’s three kinds of strength (tension, compression, and shear), modulus of elasticity, and six Poisson’s ratios with the help of digital image correlation (DIC) technology and self-created material testing methods. The (1) tensile, compressive, and shear strengths and moduli in longitudinal, radial, and chordal directions; (2) tensile strengths and moduli of bamboo green, flesh, and yellow layers in the thickness direction of the bamboo wall; and (3) six Poisson’s ratios under tensile and compressive stresses were obtained for YDS. It was also found that the tensile strength (378.8 MPa) of the green layer of YDS exceeded the yield strength (355 MPa) of 45# steel, making it a potential high-strength engineering material or fiber-reinforced material.
In order to investigate the mechanism of the effect of asymmetric reinforcement on the static-bending properties of wood, this paper tests and analyzes the static-bending properties of SPF wood and seven different types of asymmetric fiber surface-reinforced wood (AFRWC) formed by SPF wood as the substrate and bamboo and carbon fibers as the reinforcement materials. The results of the study found that (1) the moduli of rupture of the seven types of AFRWC were increased to varying degrees, but the static-bending moduli of elasticity increased or decreased; (2) the asymmetric reinforcement changed the cross-section strain distribution and damage type of the wood in static bending; (3) the results of the cross-section strain-field tests and the ABAQUS finite element simulation showed that the asymmetric reinforcement method of bonding the bamboo material and the two layers of CFRP in the compression and tensile zones, respectively, can greatly enhance the static-bending performance of the wood. The error between the simulated and measured values of specimens MOR and MOE is only −0.7% and −7.3%, respectively. This type of asymmetric reinforcement makes it possible to obtain a more reasonable cross-section stress distribution.