Interference Set on Wood Connecting Joint with Compressive Set and Recovery

利用木材的流变性和形状记忆特性，对过盈配合连接接头进行了研究。第一步是在热水中压缩一根伸缩头，第二步是将其压缩变形固定。在第三步中，将被压缩的榫头插入插眼后，用热水回收被压缩的箍头。在回收高含水率的压缩凸耳后，连接接头的抗拉强度为3kN，高抗拉强度估计为紧配合。但是，连接接头在风干中干燥到含水率后，连接接头变得完全松散。我们的试验最终以失败告终。然后，我们调查了连接接口与接口和接口，它们的尺寸在深度方向是不同的。在深度方向上分别制作了锥形和阶梯形两种不同形状的燕尾形和阶梯形的箍头。凸台的尺寸为深度50 mm、窄侧30 mm、宽侧80 mm。使用了压缩和恢复技术，将凸起插入插眼中。将接头风干后，T型接头的抗拔强度为5kN，7度斜度的锥头接头为2kN。这种新的接头连接方法是可行的。

Using rheological property and shape memory of the wood, we investigated the connecting joint with interference fit. A tenon was compressed under hot water at the first step and the compressive deformation of the tenon was fixed at the second step. At the third step, the compressed tenon was recovered with hot water after the compressed tenon was inserted into the mortise. Immediately after the compressed tenon with high moisture content was recovered, the pull strength of the connecting joint was 3kN and the high pull strength was estimated as tight fit. But, after the connecting joint was dried to moisture content in air-dry, the connecting joint became perfectly loose fit. Our trial ended in the failure.Then, we investigated the connecting joint with the tenon and mortise that their dimensions were varied in the depth direction. The taper tenon (variety housed dovetail) and the step tenon (T type) in the depth direction were made. Dimensions of the tenon were 50mm depth, narrow side 30mm, and wide side 80mm. Compression and recovery technique were utilized in the insertion of the tenon to mortise. After the connecting joint was dried to moisture content in air-dry, the pull strength of the T type connecting joint was 5kN and one of the taper tenon with 7 degrees slope was 2kN.This new connecting joint method was found the possibility.