Stranded wire consists of individual wires wound together. Key quality assurance checks include tensile testing with strain measurement, for which ZwickRoell supplies aspecial testing system able to cover all the requirements of established testing standards such as EN 10138. Spanish company Tycsa is confident that this testing solution can meet its needs.
The testing machine (Fmax 600 kN) is equipped with hydraulic grips with special jaw inserts. These ensure that the specimen is held securely, while avoiding specimen breaks at the clamped location. Tensile tests are performed on high-tensile wire up to 10 mm diameter and stranded wire up to 20 mm diameter, with lengths up to 1000 mm. A special feature of the testing machine is the ability to carry out deflected tensile tests to ISO 15630. The moving crosshead of the testing machine is provided with a through hole for these tests.
Preliminary tests at ZwickRoell's premises convinced Tycsa's representatives of the testing system’s capabilities, secure specimen clamping being a particular consideration.
Failure of stranded wire generally results in individual wires whipping about, with a consequent risk of damage tocontact-type extensometers. ZwickRoell therefore employs optical long-travel extensometers for safe, reliable, accurate measurements on stranded wire. The lightXtens extensometer achieves a resolution of 5 µm over the entire measurement travel of up to 900 mm and satisfies the requirements of Accuracy Class 1 (ISO 9513). The gage marks on the specimen plus the initial gage-length are automatically identified by the extensometer.