演讲：Mortise and Tenon Joint榫卯

Posted 2023-03-20

参考技术A Tenon and mortise joints are a sort of structure used to create stable connection of building materials. Tenon,which is 榫 in Chinese, is a projection at the end of a timber. Mortise,which is 卯 in Chinese, is a recess cut into a piece of wood. A tenon can be inserted or shifted into a mortise. And that is the most basic form of a joint. Starting with this, ancient carpenters and architects have designed a great variety of joints over thousand of years. 

Wood,stone,brick etc. Architecture, furniture, tools, as well as decorations (houses,bridges,wells,temples,beam,frame,desk,chair etc).

According to Wikipedia, the first piece of tenon and mortise joint appeared in Europe is in a period Linear Pottery Culture, which is about 4,000 to 5,000 years BC. Actually,the history of this technique dates back to 7000 years BC in Hemudu sites found in China. 

There are several reasons why this technique has been widely used. 

First, in ancient times, wood and stones are easy to find, process and transport while metals are rare and expensive. The technique and tool of processing wood developed quickly. So it’s relatively more convenient to use wood to build house and the wooden structure came on the stage. Nails made of metal were seldom used. 

Second, it follows the direction of the grain. It’s neat,stable and strong. With in a well-designed joint, different parts interlock with perfect fit, and will not wobble or slide. Additionally, when an earthquake happens, tiny space between can eliminate the effect and hold the structure firmly. And that is why a wooden palace can survive natural disaster and stand still for hundred of years without big repairing. It makes full use of the timbers’ own gravity and mutual restraints among them. As a result, there’s no need of fasteners or glues. So it’s less likely for the joints to get loose.

Third, the tenon and mortise joints consist of several parts. So it can be assembled and taken apart easily when needed and easily transported or replaced.

However, we cannot find many tenon and mortise joints now in our daily life or among the modern buildings. This is because as our technology develops, new materials appear like mushrooms. We now have all kinds of metals, plastics, concrete, glass fibres, and many other mixed resources. Our market grows quickly. Forests are disappearing and the handmade cost is increasing. Tenon and mortise joints are no longer the best choice. We may only see them like Chinese brain-training toys or specific high-class products. 

Respect the nature. Adapt to the natural dispositions of the materials. 

Overcome difficulties. Use materials to achieve our goal and also reveal the beauty. 

Minimalism. Discover the simplest way of doing things.

榫卯结构是一种用于稳定接合建筑材料的结构。榫是有突出的部分，而卯则是有凹处的部分。榫与卯常采用嵌插或滑扣的方式相接。这就构成了一个基本的榫卯结构。由此，古代工匠数千年来设计了各种各样的榫卯。

可以用榫卯结构接合的材料通常是木、石和砖，应用遍及建筑设施(如住宅、寺庙、桥梁、水井，从房梁、基柱到穹顶边框)、家具（桌、椅、台、凳、床、柜、龛、屏）、工具和艺术品（从装饰细节到手件把玩）等。

据维基百科记录，在欧洲，榫卯结构体最早出现于公元前4000到5000年的Linear Pottery Culture时期。事实上，这一工艺的历史可远溯到公元前7000年中国河姆渡文化。

榫卯结构的广泛利用背后有着许多原因。

第一，在不发达的古代，相比起稀少而昂贵的金属，木材与石块更容易找到、加工和运输。木制品的加工技术和工具也快速发展。因此，使用木材建房屋更为方便，包括榫卯在内的木接结构应运而生。金属制的钉子则并不常用。

第二，榫卯结构尊重了纤维方向，简洁、稳定、强韧。在设计精巧的榫卯接合中，不同部分完美契合在一起，不会摇晃或滑动。且当地震发生时，其中的细小空间能减轻影响，牢固地支撑起整个结构。因此，一座木制的宫殿可以经受自然考验，数百年来不需大规模修缮依然屹立不倒。它对木材自重与其相互作用的利用非常充分，故无须再用锁扣或胶水，不易松垮。

第三，榫卯结构便于装卸，可以根据所需轻易拆开、运输和组装。

然而，我们现在在生活中，在现在建筑上，很难再见到榫卯结构的身影。这是因为随着科技发展，新材料如同雨后春笋：各种金属，塑料，混凝土，玻璃纤维，和其他混合材料。市场需求量快速增长，森林消失，手工生产成本的增加……榫卯结构不再是最优的选择。我们或许只能以智力玩具或高端定制品的形式见到它们了。

尊重自然。适应材料的自然本质。

克服困难。利用现有材料以创新的方式满足应用需要，同时展现设计的美感。

简约。发现完成事情的最简方法。

（Integrated Study课个人演讲稿，主题是介绍科学发明。）