Influence of Material Characteristics on Warp In Norway Spruce Studs
Keywords:
Twist, bow, crook, compression wood, grain angleAbstract
The aim of this study was to find parameters that cause warp. The study comprised 190 studs (45 X 95 X 2500 mm) of Norway spruce (Picea abies) from Sweden. Warp was measured five times in different moisture conditions. A number of parameters were registered on the studs, for example, average distance from the pith, grain angle, amount of juvenile wood, ring width, compression wood distribution on the surfaces, knots, cracks, wane, density, and modulus of elasticity. Grain angle and annual ring curvature were found to explain 73% of the variation in twist. Bow and crook were not possible to explain with statistical models. However, the distribution of compression wood on the surfaces of the studs could most often reveal the direction of bow and crook.References
Archer, R. R. 1987. Growth stresses and strains in trees. Springer-Verlag, Berlin, Germany.nArganbright, D. G., J. A. Venturio, and M. Gorvad. 1978. Warp reduction in young-growth ponderosa pine studs dried by different methods with top-load restraint. Forest Prod. J. 28(8):47-52.nBalodis, V. 1972. Influence of grain angle on twist in seasoned boards. Wood Science 5(1):44-50.nBeard, J. S., F. G. Wagner, F. W. Taylor, and R. D. Seale. 1993. The influence of growth characteristics on warp in two structural grades of southern pine lumber. Forest Prod. J. 43(6):51-56.nBjörklund, L., L. Moberg, and H. Lindström. 1998. Stand and tree selection—Field measurements of stand, trees, and log properties. Final Report sub-task AB1.1. FAIR CT 96-1915. Report STUD.SIMS.FR:AB1.01. Swedish University of Agricultural Sciences, Dept. of Forest-Industry-Market Studies, Uppsala, Sweden.nBrazier, J. D. 1965. An assessment of the incidence and significance of spiral grain in young conifer trees. Forest Prod. J. 15:308-312.nCown, D. J., A. N. Haslett, M. O. Kimberly, and D. L. McConchie. 1996. The influence of wood quality on lumber drying distortion. Annales des Sciences Forestières 53(6):1177-1188.nDanborg, F. 1994. Drying properties and visual grading of juvenile wood from fast grown Picea abies and Picea sitchensis.Scand. J. Forest Res. 9:91-98.nDu Toit, A. J. 1963. A study of the influence of compression wood on the warping of Pinus radiataD. Don timber. S. African Forestry J. 44:11-15.nForsberg, D. 1999. Warp, in particular twist, of sawn wood of Norway spruce (Picea abies). Doctoral thesis, Swedish University of Agricultural Sciences, Dept. of Forest Management and Products, Silvestria 119, Uppsala, Sweden.nFridley, K., and R. C. Tang. 1993. Modelling three-dimensional distortion of wood due to anisotropic shrinkage. Mathematical and Computer Modelling 17(9):23-30.nGaby, L. I. 1972. Warping in southern pine studs. USDA Forest Service, Research paper SE-96, Southeastern Forest Experiment Station, Asheville, NC.nHallock, H. 1965. Sawing to reduce warp in plantation loblolly pine studs. USDA Forest Service, Forest Prod. Lab. Research paper FPL-51, Madison, WI.nJohansson, G., I. R. Kliger, and M. Perstorper. 1994. Quality of structural timber—Product specification system required by end-users. Holz Roh-Werkst. 52(1):42-48.nJohansson, M. 2000. Moisture-related distortion of Norway spruce timber—Influence of material properties. Licentiate thesis, Chalmers University of Technology, Div. of Steel and Timber Structures, Publ. S00:4, Göteborg, Sweden.nJohansson, M., and R. Kliger. 2000. Statistical and analytical analysis of distortion in Norway spruce timber. Final Report sub-task B7.1. FAIR CT 96-1915. Report STUD.CTH.FSR:B7.1. Chalmers University of Technology, Div. of Steel and Timber Structures, Publ. S00:2, Göteborg, Sweden.nJohansson, M., M. Perstorper, I. R. Kliger, and G. Johansson. 2001. Distortion of Norway spruce timber—Part 2. Modelling of twist. Holz Roh-Werkst. 59(3):155-162.nKliger, R. 1997. Field measurements in forests and at sawmills. Project Report sub-task AB1.1.FAIR CT 96-1915. Report STUD.CTH.PR:AB1.01. Chalmers University of Technology, Div. of Steel and Timber Structures, Göteborg, Sweden.nKliger, R. 1999. Quantification of distortion in sawn timber—Measured after sawing, after drying and during different moisture loads. Final Report sub-task B6.1. FAIR CT96-1915. Report STUD.CTH.FSR:B6.1.Chalmers University of Technology, Div. of Steel and Timber Structures, Göteborg, Sweden.nKliger, R., M. Johansson, M. Perstorper, and G. Johansson. 2001. Distortion of Norway spruce—Part 3. Modelling bow and spring. Holz Roh- Werkst. 59 (in press).nKloot, N. H., and M. W. Page. 1959. A study of distortion in Radiata pine scantlings. Tech. Paper No. 7, Division of Forest Products, CSIRO, Australia.nLind af Hageby, A. 1998. Samband mellan jurved i grantimmer och sägutbytenas deformation (Relation between compression wood in Norway spruce and the stud deformation, in Swedish). Swedish Univ. of Agricultural Sciences, Dept. of Forest Products, Master's thesis, Uppsala, Sweden.nMerforth, C., and U. Seeling. 2000. Statistical and analytical models. Final Report sub-task B7.1. FAIR CT 96-1915. Report STUD-ALUFR.FSR:B7.1. Albert-Ludwig's University, Department of Forest Utilization and Forestry Work Science, Freiburg, Germany.nMishiro, A., and R. E. Booker. 1988. Warping in new crop Radiata pine 100 x 50 mm boards. Bull. Tokyo Univ. Forests 80:37-68.nOkuyama, T., and Y. Sasaki. 1979. Crooking during lumbering due to residual stresses in the tree. Mokuzai Gakkaishi 15(11):681-687.nOrmarsson, S. 1999. Numerical analysis of moisture related distortion in sawn timber. Doctoral thesis, Department of Structural Engineering, Chalmers University of Technology, Göteborg, Sweden.nPersson, K. 1997. Modelling of wood properties by a micromechanical approach. Report TVSM-3020, Division of Structural Mechanics, Lund Institute of Technology, Lund University, Sweden.nPerstorper, M., P. J. Pellicane, I. R. Kliger, and G. Johansson. 1995. Quality of timber products from Norway spruce. Part 2: Influence of spatial position and growth characteristics on warp. Wood Sci. Technol. 29:339-352.nPerstorper, M., M. Johansson, I. R. Kliger, and G. Johansson. 2001. Distortion of Norway spruce timber—Part 1. Variation of relevant wood properties. Holz Roh- Werkst. 59(1-2):94-103.nRault, J. P., and E. K. Marsh. 1952. The incidence and sylvicultural implications of spiral grain in Pinus longifolia, Roxb. in South Africa and its effect on converted timber. Commonwealth Forestry Conference, Canada.nShelly, J. R., D. G. Arganbright, and M. Birnbach. 1979. Severe warp development in young-growth Ponderosa pine studs. Wood Fiber 11(1):50-56.nSimpson, W. T., and T. D. Gerhardt. 1984. Mechanism of crook development in lumber during drying. Wood Fiber Sci. 16(4):523-536.nSimpson, W. T., and J. Tschernitz. 1998. Effect of thickness variation on warp in high-temperature drying plantation-grown loblolly pine 2 by 4's. Wood Fiber Sci. 30(2):165-174.nSkaar, C. 1988. Wood-water relations. Springer Series in Wood Science, Springer-Verlag, Berlin, Germany.nStevens, W. C., and D. D. Johnston. 1960. Distortion caused by spiral grain. Timber Technology 68:217-218.nTaylor, F. W., and F. G. Wagner. 1996. Impact of log sweep on warp in Douglas fir structural lumber. Forest Prod. J. 46(9):53-56.nTimell, T. E. 1986. Compression wood in gymnosperms. Springer-Verlag, Berlin, Germany.nVoorhies, G., and B. R. Blake. 1981. Properties affecting drying characteristics of young-growth Ponderosa pine. Arizona Forestry Notes, No. 14, School of Forestry, Northern Arizona University, Flagstaff, AZ.nWarensjö, M., and C. Lundgren. 1998. Samband mellan tjurved och formfel hos gran—En studie vid limmareds sägverk, (Impact of compression wood on deformations of sawn spruce (Picea abies (L.) Karst.), in Swedish). Swedish Univ. of Agricultural Sciences, Dept. of Forest Products, Report No. 255, Uppsala, Sweden.nWoxblom, L. 1999. Warp of sawn timber of Norway spruce in relation to end-user requirements—Quality, sawing pattern and economic aspects. Doctoral thesis, Swedish University of Agricultural Sciences, Dept. of Forest Management and Products, Silvestria 126, Uppsala, Sweden.n
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