Tension Member Failure

There are several factors that can lead to the failure of a tension member in structural engineering. The failure can occur due to excessive elongation, rupture of a critical section, buckling of the member, or shear block failure of the end connection. It is important to understand each of these failure modes in order to design and analyze tension members effectively.

1. Excessive Elongation in Member:
When a tension member is subjected to a load, it experiences elongation or stretching. However, if the load exceeds the capacity of the member, the elongation can become excessive. This can occur due to factors such as inadequate material strength or improper design. Excessive elongation can lead to the failure of the member as it may cause deformation or ultimately rupture.

2. Rupture of Critical Section:
The critical section of a tension member is the location where the maximum stress is developed. If the load on the member exceeds its capacity, the stress at the critical section can reach a level that causes rupture. Rupture occurs when the material of the member is unable to withstand the applied load and it breaks apart. This type of failure is particularly dangerous as it can lead to sudden and catastrophic collapse of the structure.

3. Buckling of Member:
Buckling is another failure mode that can occur in tension members. Buckling is a phenomenon in which a slender member subjected to compressive forces deflects laterally due to instability. While tension members are primarily designed to resist tensile forces, they can still be susceptible to buckling if they are slender or have inadequate bracing. Buckling can significantly reduce the load-carrying capacity of the member and can lead to its failure.

4. Shear Block Failure of End Connection:
The end connections of tension members are crucial in transferring the applied load from the member to the supporting structure. Shear block failure occurs when the end connection is unable to resist the shear forces induced by the applied tension load. This failure mode is particularly relevant in bolted or welded connections, where inadequate strength or improper design can result in the failure of the connection and subsequently the tension member.

Conclusion:
In summary, the failure of a tension member can occur due to excessive elongation, rupture of a critical section, buckling, or shear block failure of the end connection. It is important to consider these failure modes during the design and analysis of tension members to ensure their safety and structural integrity.