Mirski Radosław, Dziurka Dorota, Chuda-Kowalska Monika, Kawalerczyk Jakub, Kuliński Marcin, Łabęda Karol
Department of Wood Based Materials, Faculty of Wood Technology, Poznań University of Life Sciences, Wojska Polskiego 38/42, 60-627 Poznań, Poland.
Institute of Structural Analysis, Faculty of Civil and Transport Engineering, Poznan University of Technology, pl. Sklodowskiej-Curie 5, 60-965 Poznań, Poland.
Materials (Basel). 2020 Sep 11;13(18):4029. doi: 10.3390/ma13184029.
The paper assessed the feasibility of manufacturing glued structural elements made of pine wood after grading it mechanically in a horizontal arrangement. It was assumed that the pine wood was not free of defects and that the outer lamellas would also be visually inspected. This would result in only rejecting items with large, rotten knots. Beams of the assumed grades GL32c, GL28c and GL24c were made of the examined pine wood. Our study indicated that the expected modulus of elasticity in bending was largely maintained by the designed beam models but that their strength was connected with the quality of the respective lamellas, rather than with their modulus of elasticity. On average, the bending strength of the beams was 44.6 MPa. The cause of their destruction was the individual technical quality of a given item of timber, which was loosely related to its modulus of elasticity, assessed in a bending test. Although the modulus of elasticity of the manufactured beam types differed quite significantly (11.45-14.08 kN/mm), the bending strength for all types was similar. Significant differences occurred only during a more detailed analysis because lower classes were characterized by a greater variation of the bending strength. In this case, beams with a strength of 24 MPa to 50 MPa appeared.
该论文评估了将水平排列机械分级后的松木制成胶合结构构件的可行性。假定松木并非无缺陷，并且外层薄板也将进行目视检查。这将导致只拒收带有大的、腐烂节疤的木材。由所检测的松木制成了假定等级为GL32c、GL28c和GL24c的梁。我们的研究表明，设计的梁模型在很大程度上保持了预期的弯曲弹性模量，但其强度与各薄板的质量有关，而非与它们的弹性模量有关。梁的弯曲强度平均为44.6兆帕。其破坏原因是某一给定木材的个体技术质量，这与在弯曲试验中评估的弹性模量关系不大。尽管所制造梁类型的弹性模量差异相当显著（11.45 - 14.08千牛/平方毫米），但所有类型梁的弯曲强度相似。只有在更详细的分析中才出现显著差异，因为较低等级的梁弯曲强度变化更大。在这种情况下，出现了强度为24兆帕至50兆帕的梁。
