4 Types of Steel Structures: Frame, Truss, Shell & Plate

Steel structures are load-bearing systems made primarily of steel, offering high strength, light weight, good plasticity, and fast construction. They are widely used in industrial and civil buildings. Based on their stress characteristics and structural forms, steel structures fall into four main types: frame structures, truss structures, shell structures, and plate structures. Each type has unique mechanical behavior and application scenarios. Understanding these four types is essential for proper structural selection and design.

Frame Structures

Frame structures consist of steel columns and beams connected by rigid or hinged joints, forming a multi-story or multi-span load-bearing system. Vertical loads transfer from beams to columns and then to foundations, while horizontal loads are resisted by beam-column joints and bracing systems. Frame structures offer flexible floor plans, high space utilization, and excellent seismic performance. They are the first choice for high-rise office buildings, hotels, hospitals, schools, and residential buildings. Depending on seismic requirements, frames can be pure frames, braced frames, or eccentrically braced frames, often combined with concrete cores for super high-rise buildings.

Truss Structures

Truss structures consist of top chords, bottom chords, and web members arranged in triangular or trapezoidal grids. All members primarily carry axial tension or compression, with minimal bending moments. This efficient use of steel results in light weight, high stiffness, and small deflection. Truss structures are ideal for large-span roofs and floors, commonly seen in stadiums, theaters, airport terminals, railway stations, large factories, and bridges. Planar trusses can span 30 to 60 meters, while space trusses can exceed 100 meters, with the added benefit of allowing pipes and equipment to pass through.

Shell Structures

Shell structures are curved thin-plate forms that carry external loads through membrane forces within the curved surface. They offer rational stress distribution, high stiffness, and material efficiency. Common shell forms include cylindrical shells, spherical shells, and hyperbolic paraboloid shells. Since steel can be fabricated into various curves, shell structures are both aesthetically striking and capable of spanning large areas. They are widely used in large stadiums, exhibition centers, storage silos, oil tanks, and gas holders. Shell structures require high construction precision but deliver iconic architectural statements.

Plate Structures

Plate structures consist of steel plates assembled into solid-web or open-web members. Common forms include steel plate shear walls, box girders, ribbed slabs, and composite steel plate structures. These structures rely on the bending, shear, and in-plane stiffness of steel plates to carry loads. They are mainly used in lateral load-resisting systems of high-rise buildings, steel box girders for bridges, crane beams in heavy industrial plants, and special applications like dry docks and lock gates. Plate structures offer high integrity and load capacity but have relatively higher steel consumption, making them suitable where rigidity and stability are critical.

Selecting the right steel structure boosts construction speed, safety, and long-term savings. Frame, truss, shell, and plate structures each solve different problems in modern buildings，knowing their strengths helps you deliver the best results, especially on complex commercial, industrial, or infrastructure projects.

For more information needed or any inquiry,please feel free to contact Yumisteel team.