电线电缆柔软性定量测试方法探讨

Discussion on Quantitative Testing Method for Wire and Cable Flexibility

针对目前国内外电线电缆领域对于电线电缆柔软性的定量测试需求,深入探讨了标准GB/T 4074.3—2008和EN 3475-704中与电线电缆柔软性相关的测试方法,比较了两个标准中测试方法的优缺点及适用范围。标准GB/T 4074.3—2008中测试方法适用于表征线缆的屈服应力,不适于表征电缆的柔软性。标准EN 3475-704中测试方法更适于电线电缆柔软性的测试,测试方法1适合于大尺寸线缆柔软性的测试,柔软性的表征参数为电缆圆环(内径为40 Dmax)压缩位移为10 Dmax时的压缩力,测试方法2适合于小尺寸线缆柔软性的测试,柔软性的表征参数为使线缆弯曲90°所施加的载荷。通过分析标准EN 3475-704中测试方法,发现测试方法1受重力影响,具有一定测试缺陷,为此提出了通过采用将试样水平放置以有效避免重力的影响,并对测试方法1和测试方法2的各测试参数提出了公差范围的限定,以方便测试实施。

In view of the current quantitative testing requirements for wire and cable flexibility in the field of wire and cable at home and abroad,the test methods related to wire and cable flexibility in standard GB/T 4074.3—2008 and EN 3475-704are discussed in depth,and the advantages,disadvantages and application scope of the test methods in the two standards are compared.The test methods in standard GB/T 4074.3—2008are suitable for characterizing the yield stress of cables and not suitable for characterizing the flexibility of cables.The test methods in standard EN 3475-704are more suitable for testing the wire and cable flexibility.Test method 1is suitable for testing the flexibility of large-sized cables.The characterization parameter of flexibility is the compression force when the compression displacement of the cable ring(inner diameter is 40 Dmax)is 10 Dmax.Test method 2is suitable for testing the flexibility of small-sized cables.The characterization parameter of flexibility is the load applied to make the cable bend 90°.By analyzing the test method of standard EN 3475-704,it is found that test method 1is affected by gravity and has some test defects.Therefore,it is proposed that the influence of gravity can be effectively avoided by placing the sample horizontally,and the tolerance limits of test parameters of test methods 1and 2are proposed to facilitate test implementation.