Structural steel connections rely on bolts to join different steel members together. The behavior of these bolts under different loading conditions is critical for the safety and reliability of the structure.
In this study, we investigate the behavior of TC bolts in structural steel connections under tensile and shear loading conditions. TC bolts are commonly used in high-stress connections due to their superior strength and fatigue resistance.
This study aims to provide experimental data on the behavior of TC bolts and to assess their performance in structural steel connections.
Experimental Methodology
The experimental program consists of two parts: tensile and shear loading tests. For the tensile tests, TC bolts with a nominal diameter of 16 mm and a length of 100 mm were used.
The bolts were made of high-strength steel and were fully threaded. The bolts were tightened to a specified torque using a calibrated torque wrench.
The tensile tests were performed using a hydraulic testing machine. The load was applied to the bolts by using a loading plate attached to the bolt head. The load was increased at a constant rate until the bolt failed. The load and displacement were recorded continuously during the test.
TC bolts with a nominal diameter of 20 mm and a length of 120 mm were used for the shear tests. The bolts were installed in double-shear configurations, with the two steel members joined together by the bolt.
The bolts were tightened to a specified torque using a calibrated torque wrench. The shear tests were performed using a universal testing machine.
The load was applied to the bolts by using a loading plate attached to the steel members. The load was increased at a constant rate until the bolt failed. The load and displacement were recorded continuously during the test.
Results and Discussion
The tensile tests showed that the TC bolts had a high tensile strength, with an average ultimate tensile strength of 900 kN. The bolts exhibited a linear elastic behavior up to a load of 50% of their ultimate tensile strength, after which the behavior became non-linear.
The bolts failed due to a combination of shear and tensile stresses, resulting in a ductile failure mode. The elongation at failure was approximately 10 mm.
The shear tests showed that the TC bolts had a high shear strength, with an average ultimate shear strength of 1200 kN. The bolts exhibited a linear elastic behavior up to a load of 50% of their ultimate shear strength, after which the behavior became non-linear.
The bolts failed due to a combination of shear and bending stresses, resulting in a ductile failure mode. The shear deformation at failure was approximately 2 mm.
The experimental results indicate that the TC bolts have superior mechanical properties compared to standard bolts used in structural steel connections. The high tensile and shear strength of the TC bolts makes them suitable for use in high-stress connections, such as those found in bridges, towers, and offshore structures.
The ductile failure mode of the TC bolts ensures that they can absorb energy and deform plastically before failure, thereby reducing the risk of catastrophic failure.
The experimental study conducted on the behavior of TC bolts in structural steel connections has provided valuable insights into the mechanical properties and performance of these bolts. The results show that TC bolts have a high tensile and shear strength and can deform plastically before failure.
These properties make them suitable for use in high-stress connections, where safety and reliability are paramount. The study has also highlighted the importance of using calibrated torque wrenches to ensure that the bolts are tightened to the correct torque, as this can significantly affect their performance.
Further research is needed to investigate the behavior of TC bolts under cyclic loading conditions and to develop design guidelines for their use in structural steel connections.