Which of the following structures would not typically use internal bracing?

Internal bracing is an important structural component that adds rigidity and stability to various types of constructions. In this context, inflatable structures are unique because they rely on air pressure to maintain their shape and structural integrity. The design of inflatable structures typically involves a flexible skin that acts like a balloon, where the air pressure inside provides the necessary strength to support loads.

Since these structures do not depend on rigid components for their stability and load-bearing capacity, they do not require internal bracing like other structural types.

On the other hand, stressed-skin structures, thin-shell structures, and folded plate structures are designed with more rigid materials and geometric shapes that utilize internal bracing to enhance their strength and resist deformation. These types have specific load distribution requirements that necessitate bracing, which is not applicable to inflatable structures. Thus, inflatable structures fundamentally operate on a different principle that precludes the need for internal bracing.