Lesson One-Introduction of Curtain Wall Introduction （技术简介）Once we mention curtain wall, we will think of those transparent glass buildings in big cities. It even has become the proof of companies strength, the symbol of a city, the reflection of human advancement and the mark of the times. Curtain wall industry has begun since 1978, and after twenty years development, China has become the largest curtain wall producing and using country. In order to understand curtain wall, we should first know some basic knowledge about the Wall. In a building there are many walls that can be divided into main walls and non-main walls that include partitions, complementary walls and curtain walls. The partitions are used for comparting the internal space of a room, and their weight is burdened by the floor or by the beam. Those walls filled between columns of the building are called complementary walls, and those hung among or in the surface of the outer-framework of the building are called curtain wall. II Conversation （会话）Welcome to Yuan Da exhibition hall. It is my honor to introduce our products to you. After my introduction, you can look around in the hall. If you have any questions, please dont hesitate to ask me.Mmanufacturer, CcustomerC: Im still a little bit confused about curtain wall, would you please tell me something more about it?M: Yes! Curtain wall is made up of supporting structure and panel, which is moveable from the main structure and can share load and effects applied upon the building. It is an envelope or decoration for the building. C: Compared with the traditional wall made of bricks and concrete, what features does curtain wall have?M: 1. Curtain wall has an integrated structure system, which receives the load directly imposed on and then delivers it to the main structure;2. Curtain wall should cover the main structure of the building;3. Usually the curtain wall connected with the main structure is movable when the main structure moves.C: What are the differences between outer decorative panel and curtain wall, and what about window?M: Generally speaking, the outer decorative panel is opaque panel. So its force bearing and function are different from curtain wall. For windows, telling from the structure, curtain wall is a consecutive outer protection system, which hangs on the main structure. While window is a disconnected outer protection system that lay in the main structure. Judged from the contradictive words: hang and lay, on and in main structure, consecutive and disconnected, the differences between them are obvious.C: Do curtain wall and skylight belong to the same category?M: No, they are not. Its very simple for you to distinguish them. If inner angle between the panel and horizon is less than 75 degree, it is skylight; otherwise, its curtain wall.C: It seems that there are many kinds of curtain walls. Can you give me a brief introduction about them?M: According to different materials: glass curtain wall, metal board curtain wall, stone curtain wall, composite curtain wall.According to different decorative effects: exposed frame curtain wall, hidden frame curtain wall, semi-hidden frame curtain wall.According to different structures: stick curtain wall, unitized curtain wall, semi-unitized curtain wall.C: What are the glass strips vertically sticking to the glass wall used for? M: They are “Glass Ribs”. As the size of the glass used in curtain wall is too big, it will bear too much force of wind that may cause deformation of the glass. Ribs could prevent this.C: When connecting curtain wall with main structure, what should we pay attention to? M: When the mullion of the curtain wall is made of aluminum alloy, the different deformation will take place between aluminum alloy and steel because of their different thermal expansion coefficients and they will bring about the temperature stress between aluminum alloy mullion and steel truss. So we must bring the influence of the temperature stress into consideration. A good method is making the connection movable in order to lessen the temperature stress.C: Are the load and the effect applied upon curtain wall the same conception?M: No, they are not. The effects mean all the causes that can influence the structure. They include the accumulated force and the distributed force applied upon the structure, and the causes of composing the applied structural deformation or constraint deformation. The former one is force accumulated on the structure, which is commonly called load. However, the effects also include the change of temperature, the shrink of the materials, the deformation of function and the earthquake, but they dont belong to the load.C: what should we pay attention to prevent the damage from the load and effect from the environment?M: 1. we should ensure the panel having enough load-supporting force;2. we should ensure the connective