Effects of embedment side and loading direction on embedment strength of cross‑laminated timber for smooth dowels
Effects of embedment side and loading direction on embedment strength of cross‑laminated timber for smooth dowels
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埋入侧面和加载方向对光销用交叉层压木埋入强度的影响
DOI：
10.1007/s00107-019-01490-z
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发表时间：
2020
影响因子：
2.6
通讯作者：
Meng Gong
中科院分区：
文献类型：
--
作者：
Weiqun Dong;Qiao Li;Zhiqiang Wang;Hao Zhang;Xiaoning Lu;Meng Gong
嵌固强度是正交层积木结构中销式连接的决定性力学性能。销钉可以安装在CLT的平面或/和窄侧，这可能导致不同的销钉嵌入强度。为研究嵌固侧和加载方向对CLT嵌固强度的影响，采用ASTM D5764- 97 a半孔试验方法，对6组预钻半孔的立方体试件进行了3个嵌固位置和2个加载方向的试验。结果表明，嵌固面、加载方向和横向层厚比对CLT的嵌固性能有显著影响。各组的载荷-变形行为和破坏模式有显著差异。埋置试验表明，横向夹层的存在降低了CLT的埋置强度，提高了CLT的延性。当只有一层木材承受平行于木材纹理方向的载荷时，裂纹沿该层木材的纹理沿着发生。当横、纵两层共同承担传力杆的荷载时，CLT的延性较好。对于安装在窄边的销钉，最大和最小嵌入强度值分别为37.66 MPa和12.55 MPa。对于安装在平面侧的销钉，随着TRTL的增加，嵌入强度降低。现有设计模型计算的嵌固强度与试验值存在较大差异。这些发现对于提供安全有效的关节以实现更有效地使用CLT产品非常重要。
Embedment strength is a decisive mechanical property of the dowel-type connection in cross-laminated timber (CLT) structures. Dowels can be installed in the plane or/and narrow side of CLT, which may result in different dowel embedment strength. To investigate the effects of embedment side and loading direction on the embedment strength of CLT, six groups of cubic specimens with predrilled half-holes, including three embedment positions and two loading directions, were tested according to the ASTM D5764-97a half-hole test method in this study. It was found that the embedment side, loading direction and the thickness ratio of transverse layer (TRTL) of CLT had significant influences on CLT embedment properties. The load-deformation behaviors and failure modes of each group were significantly different. The existence of transverse layers could reduce the embedment strength and improve the ductility of CLT under embedment tests. When only one layer bore the load parallel to the grain of wood, the crack occurred along the grain of this layer. When the transverse and longitudinal layers shared the dowel embedment load jointly, CLT had a better ductility. For dowels installed in the narrow side, the maximum and minimum embedment strength values were 37.66 MPa and 12.55 MPa, respectively. For dowels installed in the plane side, the embedment strength decreased with the increase in TRTL. The embedment strength of CLT calculated by the existing design models was different from the experimental values. These findings are important to providing a safe and efficient joint to achieve more efficient use of CLT products.