Zugglieder

Zugglieder are structural elements in frames and trusses designed to carry axial tensile forces. They resist pulling forces at joints and help maintain the geometry of a structure under load. In a typical truss, Zugglieder balance the forces in Druckglieder (compression members) and connect joints with slender, straight members such as rods, cables or chains.

Common materials for Zugglieder include steel, timber, aluminum and fiber-reinforced polymers. The forms are often rods, cables or ties that can sustain high tension with relatively low weight. Connections are critical; Zugglieder are usually connected by pins or bolts in pin-jointed trusses, or welded to members in rigid frames. Joints must transfer axial loads without significant bending.

Design considerations include ensuring sufficient cross-section to avoid yielding under peak tensile stress, managing fatigue for cyclic loads, and addressing elongation and thermal effects. While buckling is mainly a concern for compression members, excessive tension can still cause elongation and reliability issues, especially under long-term loading or dynamic conditions.

Applications span roof and bridge trusses, suspension and cable-stayed structures, cranes, and guyed towers. Terminology-wise, the concept is often contrasted with Druckglieder in German structural engineering, where Zugglieder denote the axial-tension members and Druckglieder denote axial-compression members. Together, they describe the components that carry axial loads in a structure.