| Traditional wooden structure is a treasure with special intension in Chinese architectural culture.Therefore,the protection and development of wooden structure is of great significance.However,the amount of wood it consumes is fairly much.Under the background of"2 carbon"initiative,domestic production of wood is decreasing gradually,which could fail to support this demand.The research team the author works at had developed a compression molding wood imitation with the matrix,modified MOC of fire-proof,low-thermal conductivity and the inclusion,waste plant fibers,which could effectively alleviate the dilemma of wood structure development caused by the wood shortage.Early research of the team on physical and mechanical properties shows that the wood imitation has similar appearance,density and strength to construction wood,which could well substitute for wood.To explore the engineering application value of the wood imitation,the team has recently carried out experimental research on the bearing capacity of various wood imitation components.The results show that all kinds of components have good load-bearing performance.The team is also developing the second-generation wood imitation on the basis of first-generation.In this paper,the author conducted a preliminary study on the physical and mechanical properties of the second-generation wood imitation,carried out the failure tests of eccentric compression bearing capacity on the hollow walls and the wall keel frames manufactured of wood imitation,and established the calculation theory of imitation wood hollow wall.In this paper,the density of the second-generation imitation wood material was determined as 1210.10 kg·m-3,about 1/2 of concrete,which is similar to the construction wood;The“Z-axis”anisotropy existed in wood imitation is similar to that of wood,while wood imitation has bidirectional parallel grains,one more over wood.Through a series of material tests,the second generation wood imitation were determined to have a compressive strength of 18.78MPa,a splitting tensile strength of 4.81MPa,a static modulus of elasticity of 4200MPa,and a Poisson’s ratio of 0.252.Six loading velocities were used in the compressive stress-strain curve test,the optimal test loading velocity was determined to be 500N/s,and the constitutive relation of the compression stress-strain curve at each loading velocity was obtained.The first generation wood imitation was used to make the hollow wall and the wall keel frame specimens.Based on the physical and mechanical properties of the first generation wood imitation measured by the team earlier,out-of-plane eccentric compression tests of keel frame and hollow wall with eccentricities of 10mm and 30mm,fixed-hinged supports were carried out.The result reveals that the bearing capacity of the two types of specimens decreases with the increase of the eccentricity.The keel frame damage mode change from small-eccentric damage under 10mm eccentricity,into large-eccentric damage under 30mm eccentricity.The hollow wall presented small-eccentric damage under both the eccentricity of 10mm and 30mm,and a higher bearing capacity over the keel frame,which shows that the synergistic effect of the wood imitation wallboard and the wall keel frame is obvious.Compression theory of eccentric rod with fixed-hinged supports was deduced,the deflection curve formula with different stiffnesses,different sizes,and different eccentricities was obtained,and the position and value of maximum deflection were determined.On the basis of this theory,the bearing capacity analyses of the keel frame and the hollow wall were carried out,and the theoretical value of the bearing capacity is obtained,which is close to the measured one,showing that the theory has good applicability to wood imitation hollow wall and keel frame.Based on the compression theory of eccentric rod with fixed-hinged supports,the calculation theories for the bearing capacity of accentric compressing were established assisted by measured data.In the end,the conclusion is drawed from the paper and the future application prospects of wood imitation are prospected.. |
