This standard specifies the test equipment, sample preparation, test steps, test results and calculations for tear resistance test. This standard is applicable to the determination of the tear resistance of rubber sheaths of heavy-duty rubber-sheathed flexible cables and mining-use rubber-sheathed flexible cables. GB/T 2951.34-1994 Test methods for mechanical and physical properties of wires and cables Tear resistance test GB/T2951.34-1994 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Test method for determining mechanical and physical properties of electric cahles and wiresTear lest
1 Content and scope of application
GB/T 2951.3494
Replaces 2951.3483
This standard specifies the test equipment, sample preparation, test procedures, test results and calculations for the tear test. This standard is applicable to the determination of the tear resistance of rubber sheathed flexible cables and rubber sheathed flexible cables for mining use. The general provisions, definitions and regular calibration of test equipment for the mechanical and physical properties of energy wires and cables are specified in GB/T2951.1. 2 Reference Standards
GB/T 251.194 Test Methods for Mechanical and Physical Properties of Electric Cables General 3 Test Equipment
3.1 Tensile Test Pick, the indication accuracy is 1/10 of the maximum range of each level dial, but not less than the maximum negative micro 4% and starts from 1, 3.2 Test piece cutter as shown in Figure 1,
Figure! Tear test piece cutter
3.3 Pointer-type thickness gauge
4 Sample Preparation
Accuracy 0.01 mm.
4.1, from each cable sheath to be tested, cut a sample sufficient to prepare six tear test pieces along the axial direction of the cable State Technical Supervision Bureau 1994-07-07 Approved 1995-01-01 Implementation
GB/T 2951.34--94
4.2 Grind or flatten the sample to have roughly parallel surfaces. Care should be taken to avoid overheating when grinding. The thickness of the specimen after grinding or flattening shall not be less than 1.0 mm and not more than 4.0 mm. 4.3 Use the cutter shown in Figure 1 to cut the test piece from the specimen. The middle cut can be cut at the same time as the outer shape, or it can be cut separately. 4.4 Use the measuring tool specified in Article 3.3 to measure the thickness of each test piece at the wide end, accurate to 0.01 mm. 5 Test steps
5.1 The test piece should be pretreated in an environment of 20±5℃ for at least 3h5.2 At a temperature of 20±5℃, clamp the two sides of the cut end of the test piece in the same plane on the upper and lower clamps of the tensile machine, and gradually open the test piece at a speed of 350~500mm/min
5.3 Read the maximum tear force when tearing the test piece, and take one decimal place. 6 Test results and calculations
6.1 The tear strength is calculated as follows:
(N/mm)
Where: — Maximum tear force, V;
— Thickness of test piece, mm. bzxz.net
6.2 The test result is the median value of the tear strength of the six test pieces. Additional remarks:
This standard is proposed by the Ministry of Machinery Industry of the People's Republic of China. This standard is under the jurisdiction of the Shanghai Cable Research Institute of the Ministry of Machinery Industry. This standard is drafted by the Shanghai Cable Research Institute of the Ministry of Machinery Industry. The main drafter of this standard is Pang Huijuan.
This standard was first issued in 1983 and revised for the first time in July 1994.
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