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林业科学 ›› 2016, Vol. 52 ›› Issue (9): 107-112.doi: 10.11707/j.1001-7488.20160913

• 论文与研究报告 • 上一篇    下一篇

结构用集成材落叶松层板指接工艺

谢力生, 刘佳权, 乔鹭婷, 李贤军, 周先雁   

  1. 中南林业科技大学材料科学与工程学院 长沙 410004
  • 收稿日期:2015-07-31 修回日期:2015-10-13 出版日期:2016-09-25 发布日期:2016-10-20
  • 基金资助:
    国家林业公益性行业科研重大专项“木结构工程材制造及应用关键技术研究与示范”(201304504)。

Finger-Jointing Technique of Larch Structural Glued Laminated Timber

Xie Lisheng, Liu Jiaquan, Qiao Luting, Li Xianjun, Zhou Xianyan   

  1. College of Material Science and Engineering, Central South University of Forestry and Technology Changsha 410004
  • Received:2015-07-31 Revised:2015-10-13 Online:2016-09-25 Published:2016-10-20

摘要: [目的] 研究指榫对接所需端向压力(指接压力)与榫型参数和嵌合度的关系,探讨榫型、嵌合度、指接压力对指榫胶接力学性能的影响规律,以获得较佳的指榫胶接工艺。[方法] 采用5种不同型号的指榫铣刀,分别将兴安落叶松层板的一端加工成具有不同嵌合度的垂直型指榫,将两指榫对接并在力学试验机上加压至齿顶和槽底紧密接触,读取其压力值(各种榫型和嵌合度的试件各10对),研究指榫对接所需端向压力(指接压力)与榫型参数和嵌合度的关系;对指榫进行手工涂胶(双面施胶,施胶量为180 g·m-2),根据测试得到的指接压力对各种榫型和嵌合度的开榫木板进行对接加压胶合,试件放置24 h后按照GB/T 26899-2011《结构用集成材》中5.3.3抗弯试验方法C和5.4抗拉强度试验测试指接部位的弹性模量、静曲强度和抗拉强度(各种榫型和嵌合度的试件各10个,一半用于测试静曲强度和弹性模量,另一半用于测试抗拉强度),探讨榫型、嵌合度、指接压力对指榫胶接力学性能的影响规律,获得较佳的指榫胶接工艺。[结果] 指接压力受嵌合度的影响十分显著,随嵌合度的增大而显著增大,但各榫型下嵌合度与指接压力的关系不尽相同,同时受榫齿长、榫齿角、齿距和槽底宽等影响;各种榫型下嵌合度对指接力学性能(抗拉强度、静曲强度和弹性模量)的影响有很大差别,但仔细比较各榫型嵌合度下的指接压力与抗拉强度、静曲强度和弹性模量的关系可以发现,当指接压力在8~15 MPa时各榫型都有较大的力学强度,且该值随榫齿长度的增加而基本上呈比例地增大。[结论] 1)指榫胶接所需指接压力随嵌合度的增大而显著增大,且榫齿角和槽底宽度较小时更加显著;指接压力随榫齿长度的增加而增大;指接压力与嵌合率基本上呈正比,其斜率随榫齿角的增大而减小。2)各榫型的指接强度随榫齿长度的增加而增大;指接压力过小或过大其指接强度均下降,指接压力在8~15 MPa时各榫型都呈现较大的力学强度。3)短齿榫型产生最大指接强度的嵌合度比长齿榫型的大,榫长9和27 mm的榫型产生最大指接强度的嵌合度分别约为0.2和0.1 mm。4)从安全和经济2方面综合考虑,兴安落叶松层板的较佳指接工艺为:榫齿角9.8°、榫齿长15~20 mm、齿槽底宽0.8~1.2 mm、指接压力10~15 MPa、嵌合度0.12~0.20 mm(榫齿较长时嵌合度取较小值)。

关键词: 结构用集成材, 落叶松, 层板, 指接, 嵌合度

Abstract: [Objective] In order to obtain the optimization processing parameters of finger-jointing, the relationship of tenon's end pressure (finger-jointing pressure), fitness ratio and it's type was clarified, and the impact of tenon type, fitness ratio and finger-jointing pressure on its mechanical properties was also investigated.[Method] Using five different types of cutter to process Larix gmelinii lamina into vertical type finger-jointing tenon with different fitness ratio. Pressing two finger-jointing tenons together until the addendum contacts the groove bottom closely at mechanical machine, obtaining the value of pressure (ten couples test sample with different types and fitness ratio was used), and the relationship between the finger-jointing pressure with tenon type parameters and fitness ratio was clarified. Gluing the finger-jointing tenon manually (both surfaces were glued with consumption of 180 g·m-2), then pressing them together with the value of pressure, tenon type and fitness ratio we obtained frontally. After 24 hours, the elastic modulus, static bending strength and tensile strength of the finger-jointing tenon were test using the method of chapter 5.3.3 and 5.4, the experiment of bending and tensile strength in the book of structural glued laminated timber, the GB/T 26899-2011. Ten specimens for each tenon type and fitness ratio were available for testing. Half of them were used for elastic modulus and static bending strength testing, the rest was used for tensile strength testing. The influences of tenon type, fitness ratio, finger-joint pressure on its adhesive bonding mechanical property were disussed, and the optimization adhesive bonding parameters of finger-jointing technique were obtained.[Result] The finger-jointing pressure significantly increased with the increase of fitness ratio. However, the relationship between the fitness ratio and finger-jointing pressure was not always the same and depend on tenon type (consisting of finger length, finger angle, pitch, and alveolus width). There were pronounced difference among the influence of fitness ratio on finger-jointing mechanical properties (the elastic modulus, the static bending strength and the tensile strength) with various tenon types. All kinds of tenon exhibited better mechanical properties when the finger-jointing pressure was 8-15 MPa, and the value increased proportionally with the increase of finger length.[Conclusion] 1) The pressure required for finger-jointing adhesive bonding increased with the increase of fitness ratio, especially when tenon gear angle and width of gear bottom was smaller. Finger-joint pressure increased with the increase of tenon gear length. Generally, finger-jointing pressure was proportional to the fitness ratio, and the slope decreased with the increase of tenon gear angle. 2) For all tenon types investigated in this study, the finger-jointing strength value increased with the increase of tenon gear length. The optimal finger-jointing pressure was about 8-15 MPa, which presented greater mechanical strength value. 3) The fitness ratio of maximum finger-jointing strength obtained by short tenon gear was greater than that obtained by the long tenon gear, the fitness ratio of maximum finger-jointing strength produced by 9 mm and 27 mm tenon were approximately 0.2 mm and 0.1 mm, respectively. 4) Considered from safety and economy aspects, the optimal finger-jointing parameters of L. gmelinii lamina were: angle of tenon gear 9.8°, length of tenon gear 15-20 mm, width of gear bottom 0.8-1.2 mm, finger-jointing pressure 10-15 MPa, fitness ratio 0.12-0.20 mm (the longer the tenon gear, the smaller fitness ratio used).

Key words: structural glued laminated timber (Glulam), larch, lamina, finger-joint, fitness ratio

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