Tension members are also known as tie members or simply a tie. Tension members are designed as structural members that are subjected to tensile force in a direction which is parallel to its longitudinal axis. There are different types of tension members. Its structure and end connections determine the type of tension members in structural steel construction. The tension members made of structural steel can be broadly grouped into four categories:
Wires and Cables
The wire type tension members are used for derricks, hoists, hangers for suspension bridges, rigging slings, and guy wires
Bars and Rods
The round and square bars are frequently used for the small tension members. The round bars having threaded ends are used along with pin connections at the ends, in place of threads. The ends of the rectangular plates or bars are enlarged by forging and are bored to form eye bars. The eye bars too are used along with the pin connections. The rods and bars have a disadvantage of inadequate stiffness which results in the accumulation of noticeable sag under its own weight.
Single Structural Plates and Shapes
The single structural shapes (angle sections and tee sections) are used as tension members. The angle sections are more rigid than the wires, cables, rods, and bars. If the length of a tension member is too long, the single angle sections also become flexible. The single angle sections have a disadvantage of eccentricity in both planes in a riveted connection. The channel section has eccentricity in just one axis. The single channel sections have low rigidity in the direction of flange and high rigidity in the direction of web.
At times, the I-sections are used as tension members. They have more rigidity and single I-sections are more economical than the built-up sections.
Built-up Sections
Two or more tension members are used to form built-up members. When the single structural steel sections cannot furnish the required area, built-up sections are used. The double angle sections having unequal legs are used as tension members in the roof trusses. The angle sections are placed on the two sides of a gusset plate. When both angle sections are placed on the same side of the gusset plate, it can be subjected to tension and bending. These two angle sections can also be arranged in a star shape and can be connected by batten plates. The star shape arrangement offers a symmetrical and concentric connection.
These are the different types of tension members that you may require in your next project. To know which ones will work best for you, you can contact professional steel fabricators and get their insights.
