Definition of a Double-Wing Expandable Structure: A double-wing expandable structure typically refers to a building with an expandable design. Based on its basic structure, the two sides (i.e., the “double wings”) can be extended outward using specific mechanical devices or design features, thereby increasing the usable interior space. Generally, double-wing expandable structures have relatively compact overall dimensions during transport or when not deployed, making them easy to move and set up. Once they arrive at the designated location and installation is complete, the expansion mechanisms are activated to extend the space on both sides, creating a more spacious living or functional area to meet people’s need for larger spaces. They are commonly used in scenarios such as temporary housing, field operations, and tourism and leisure.