This paper initially applied the non-destructive evaluation-computerized tomography and the fractal theory to research the feature of wood fracture. Pinus elliottii, Populus×canadensis cv. ‘I-214’ and Larix gme...This paper initially applied the non-destructive evaluation-computerized tomography and the fractal theory to research the feature of wood fracture. Pinus elliottii, Populus×canadensis cv. ‘I-214’ and Larix gmelinii were choosed as samples. The author established the logarithm-logarithm relationship between the section area of wood fracture and its location, then defined the slope-D_L regressed by the two factors above as the section variation fractal dimension of wood fracture. The results showed: the non-destructive evaluation-computerized tomography can effectively analysis the feature of wood fracture. All the samples exist an marked linear relationship between the section area of fracture and its location, D_L is a new effective parameter to quantitatively characterize the feature of wood fracture, the delta of -2 described the complexity of fracture surface of wood. Due to the anisotropy and variation of wood properties, D_L is the statistically fractal dimension. All the results are tested by the statistic software——SARS, there exists remarkable difference between the D_L from different species. The average fractal dimension of fracture surface of Pinus elliottii is 2.25, Populus×canadensis cv. ‘I-214’ is 2.46, Larix gmelinii is 2.65.展开更多
It is very difficult to characterize the fracture surface of wood with traditional way because of its irregularity and complexity. This paper, inspired from slit island method (SIM) and mass fractal method, proposes a...It is very difficult to characterize the fracture surface of wood with traditional way because of its irregularity and complexity. This paper, inspired from slit island method (SIM) and mass fractal method, proposes a new method, by which the change of sectional area with spatial location in wood fractures can be determined, to quantify the character of fracture surfaces. The experiment is done by continuously microtoming a fractured sample embedded with paraffin at intervals of hundreds micron along the longitudinal axis from tip to end of fracture. The results indicate there exists a linear correlation between the area and the corresponding location in a double logarithm coordinate. The slope, here termed as section variation dimension (D-L), is located between 2.23 to 2.75 with the D-L of pressed zone being smaller than that of tensile zone for a wood fractured by static bending, and D-L can be used to describe quantitatively the complexity of fracture surface of wood.展开更多
文摘This paper initially applied the non-destructive evaluation-computerized tomography and the fractal theory to research the feature of wood fracture. Pinus elliottii, Populus×canadensis cv. ‘I-214’ and Larix gmelinii were choosed as samples. The author established the logarithm-logarithm relationship between the section area of wood fracture and its location, then defined the slope-D_L regressed by the two factors above as the section variation fractal dimension of wood fracture. The results showed: the non-destructive evaluation-computerized tomography can effectively analysis the feature of wood fracture. All the samples exist an marked linear relationship between the section area of fracture and its location, D_L is a new effective parameter to quantitatively characterize the feature of wood fracture, the delta of -2 described the complexity of fracture surface of wood. Due to the anisotropy and variation of wood properties, D_L is the statistically fractal dimension. All the results are tested by the statistic software——SARS, there exists remarkable difference between the D_L from different species. The average fractal dimension of fracture surface of Pinus elliottii is 2.25, Populus×canadensis cv. ‘I-214’ is 2.46, Larix gmelinii is 2.65.
文摘It is very difficult to characterize the fracture surface of wood with traditional way because of its irregularity and complexity. This paper, inspired from slit island method (SIM) and mass fractal method, proposes a new method, by which the change of sectional area with spatial location in wood fractures can be determined, to quantify the character of fracture surfaces. The experiment is done by continuously microtoming a fractured sample embedded with paraffin at intervals of hundreds micron along the longitudinal axis from tip to end of fracture. The results indicate there exists a linear correlation between the area and the corresponding location in a double logarithm coordinate. The slope, here termed as section variation dimension (D-L), is located between 2.23 to 2.75 with the D-L of pressed zone being smaller than that of tensile zone for a wood fractured by static bending, and D-L can be used to describe quantitatively the complexity of fracture surface of wood.
