Performance Of Bolt-type Tension Clamps Under Extreme Weather Conditions

What role does bolted type strain clamp play in power grid security? Especially after an accident, its performance often determines the extent of line damage. We combined on-site operational data with a database of failure cases to conduct an in-depth analysis of the actual performance of the dead end strain clamp in the accident.

Stress Analysis at Ice Disaster Sites

Extreme weather is a touchstone for testing the performance of hardware. For example, during ice disasters, operators discovered a clear pattern in the fault points of inverted clamp bolted dead end clamp clamps. When the conductor is overloaded by ice, the stress state of the clamp changes drastically. The locking system composed of its internal curved groove and U-bolt generates enormous frictional force at the moment the conductor slides. This structure, based on lever and wedge effects, provides the final gripping force during an accident. The destructive load data of the clamp body is directly converted into the safety margin of the line at this moment.

Microscopic Defects and Macroscopic Fractures of the Drain Plate

Besides bearing enormous tensile forces, accidents often lie hidden in the details. We previously analyzed a typical case of a drain plate meltdown:

• Tightening condition analysis: Macroscopic inspection revealed obvious discharge ablation marks around the drain plate bolt holes, along with black residue.

• Assembly gap analysis: Further testing revealed an abnormal gap of approximately 9mm between the bolt washer and the drain plate. This gap directly led to increased contact resistance and the generation of an electric arc during operation.

• Failure process reconstruction: Prolonged arc erosion ultimately caused fracture at the bolt hole, the point with the smallest cross-section.

In accidents, bolt-type tension clamps are not only mechanical anchoring points, but the reliability of their electrical connections is also crucial to line safety. Any lack of tightening torque in any bolt can become the starting point of an accident.