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Wood as a biomass polymer materials, its inherent large variability. This variability not only be a greater impact on the mechanical properties of wood, but also will bring a great deal of uncertainty to its processing and utilization. Scientific and rational use of wood, effectively improve the utilization of wood resources, and to ensure the safe and reliable application of a variety of wood products in the construction, must accurately predict its mechanical properties in order to achieve a level of distinction. At present, domestic and foreign common method of grading visual grading, and two types of non-destructive testing. To provide a scientific basis for non-destructive testing and destructive testing of timber explore non-destructive testing results of the mechanical properties of the relationship, not only wood can provide a more comprehensive understanding of the mechanical properties, the better to achieve fast and accurate intensity grading, has a very large theoretical significance and practical value. Firstly, according to the American ASTM D245, Japan JAS 1152, the German DIN 4074 three visual grading standard visual grading 694 full scale larch natural forest sawn timber and 221 full scale larch plantation sawn timber, and then were the use of the four non-destructive testing methods (mechanical stress grading, lateral vibration, longitudinal vibration and stress wave) and two static bending test method (ASTM D4761 three o'clock flat curved, four-point bending) of the tested material moving, static elastic modulus tested, and finally by a random sampling of the overall sample, carried out a four-point the flat curved destruction, the flexural strength of the tested material. Obtained by analyzing the relationship between the different mechanical properties, the following main conclusions: 1, the level of visual and static bending properties (three flat curved static bending modulus of elasticity E3s, four o'clock scoliosis static bending modulus of elasticity E4s anti- having a close correlation between the bending strength MOR). Good linear regression relationship between the three-point flat curved four-point bending test method (E3s E4s), the correlation coefficient R .8049 E4s the average is 8.13% higher than the E3s (1.3 GPa). 3, dynamic MOE and static MOE correlation there is a larger difference in the R range of 0.4989-0.7330. The best correlation EMSR with E4S, R reached .7730; the ELV and E3S worst, R is only 0.4989. 4 static MOE and MOR (R range of 0.6552 to 0.7535) better than the dynamic MOE MOR correlation (R range 0.3087-0.6439), of which the best correlation E4s with MOR R to 0.7535. 5, created by the method of mechanical stress, transverse vibration, stress wave longitudinal vibration method MOR prediction model correlation coefficients were 0.6439,0.5914,0.5035,0.3087 mechanical stress grading method to predict the effect of the MOR best, followed by transverse vibration method, the worst effects of the stress wave longitudinal vibration prediction of MOR.
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