Analysis Of The Correlation Between Failure Risk Of Bolt-type Tension Clamps And Safe Operation Of Transmission Lines

In high-voltage transmission networks, the bolted type strain clamp is a hardware component that bears the tension of the conductor and plays a role in load-bearing and fixing at the junction of the overhead line and the tension tower. The performance of tension clamps directly affects the mechanical stability and electrical continuity of transmission lines; failure can lead to overhead conductor breakage, operational interruptions, and even wider equipment damage and safety accidents.

Failure Mechanism

When dead end strain clamp fails, the most common causes are fatigue in the stressed parts, abnormal deformation of the crimped parts, or insufficient contact. During long-term operation, stress concentration and wear may occur at the contact surface between the tension clamp and the conductor, weakening the mechanical connection between the steel core and the aluminum outer tube, eventually leading to cracking or loss of grip. Poor crimping quality of tension clamps has also been found to be significantly associated with breakage accidents.

Typical effects include:

• Tension imbalance in overhead high-voltage conductors, causing abnormal movement or even detachment of the transmission line;

• Mechanical cascading failures in the power system, affecting the stability of adjacent tower sections;

• Accumulated thermal stress at the failure site, causing localized overheating or wire breakage on the conductor surface.

On-site Inspection and Performance Evaluation

Inspecting for a bolted dead end clamp condition requires a combination of methods, such as non-destructive testing and hardware appearance evaluation. The core of the inspection work lies in detecting crimping defects, fitting deformation, and surface wear, all of which are precursors to potential failure. NDT methods (such as radiographic imaging) are used to quantify the distribution of internal defects in tension clamps, improving the accuracy of assessment.

For operating units, developing clamp inspection plans, recording historical conditions, and implementing targeted maintenance measures are crucial aspects of managing transmission line risks.