The stress-strain relation of laminated veneer lumber (LVL) was established by the method of regression, and its constitutive equation at large deformation and constant loading conditions was given to predict the stat...The stress-strain relation of laminated veneer lumber (LVL) was established by the method of regression, and its constitutive equation at large deformation and constant loading conditions was given to predict the static mechanical behaviors of LVL.展开更多
In this study,static coefficients of friction for laminated veneer lumber on steel surfaces were determined experimentally.The focus was on the frictional behaviors at different pressure levels,which were studied in c...In this study,static coefficients of friction for laminated veneer lumber on steel surfaces were determined experimentally.The focus was on the frictional behaviors at different pressure levels,which were studied in combination with other influencing parameters:fiber orientation,moisture content,and surface roughness.Coefficients of friction were obtained as 0.10–0.30 for a smooth steel surface and as high as 0.80 for a rough steel surface.Pressure influenced the measured coefficients of friction,and lower normal pressures yielded higher coefficients.The influence of fiber angle was observed to be moderate,although clearly detectable,thereby resulting in a higher coefficient of friction when sliding perpendicular rather than parallel to the grain.Moist specimens contained higher coefficients of friction than oven-dry specimens.The results provide realistic values for practical applications,particularly for use as input parameters of numerical simulations where the role of friction is often wrongfully considered.展开更多
The hot-press temperature curves were researched and effects of hot-pressing temperature,thickness of veneer and the numbers of layer on mechanical properties of laminated veneer lumber(LVL)were analyzed with emphasis...The hot-press temperature curves were researched and effects of hot-pressing temperature,thickness of veneer and the numbers of layer on mechanical properties of laminated veneer lumber(LVL)were analyzed with emphasis in the paper.Results showed that there was positive relationship between hot-pressing temperature and modulus of elastic(MOE);the modulus of rupture(MOR)of LVL was best when manufactured at 160 ℃.When the thickness of veneers was 3.25 mm the LVL usually destroyed due to veneer tearing;while when the thickness of veneers was 1.70 mm it easily splited in adhesive layer;the mechanical properties of LVL were best when the thickness of veneers was 1.70 mm;the 3 multinomial degrees of fitting the numbers of layers with MOE and MOR of Eucalyptus LVL matched very well,the R2 value were 0.951 6 and 0.981 2,respectively.展开更多
文摘The stress-strain relation of laminated veneer lumber (LVL) was established by the method of regression, and its constitutive equation at large deformation and constant loading conditions was given to predict the static mechanical behaviors of LVL.
文摘In this study,static coefficients of friction for laminated veneer lumber on steel surfaces were determined experimentally.The focus was on the frictional behaviors at different pressure levels,which were studied in combination with other influencing parameters:fiber orientation,moisture content,and surface roughness.Coefficients of friction were obtained as 0.10–0.30 for a smooth steel surface and as high as 0.80 for a rough steel surface.Pressure influenced the measured coefficients of friction,and lower normal pressures yielded higher coefficients.The influence of fiber angle was observed to be moderate,although clearly detectable,thereby resulting in a higher coefficient of friction when sliding perpendicular rather than parallel to the grain.Moist specimens contained higher coefficients of friction than oven-dry specimens.The results provide realistic values for practical applications,particularly for use as input parameters of numerical simulations where the role of friction is often wrongfully considered.
文摘The hot-press temperature curves were researched and effects of hot-pressing temperature,thickness of veneer and the numbers of layer on mechanical properties of laminated veneer lumber(LVL)were analyzed with emphasis in the paper.Results showed that there was positive relationship between hot-pressing temperature and modulus of elastic(MOE);the modulus of rupture(MOR)of LVL was best when manufactured at 160 ℃.When the thickness of veneers was 3.25 mm the LVL usually destroyed due to veneer tearing;while when the thickness of veneers was 1.70 mm it easily splited in adhesive layer;the mechanical properties of LVL were best when the thickness of veneers was 1.70 mm;the 3 multinomial degrees of fitting the numbers of layers with MOE and MOR of Eucalyptus LVL matched very well,the R2 value were 0.951 6 and 0.981 2,respectively.
