金属材料.单轴疲劳试验用动态力校准.第1部分:试验系统

[中文适用范围]： ISO 4965 的这一部分描述了两种方法（参见简介），用于确定在单轴、正弦、恒幅测试中施加到试件的动态力范围 (ΔFt) 与测试指示的力范围 (ΔFi) 之间的关系系统。 这些方法适用于远离系统谐振频率运行的动态测试系统，并且与动态力测量误差未知或预计超过所施加力范围的 1% 的测试系统相关。 动态力测量误差是通过将动态测试系统指示的峰值力与应变动态校准装置（DCD）测量的峰值力进行比较来确定的。 该 DCD 之前已针对测试系统指示器进行了静态校准（参见 5.2.1）。 对于方法 A（复制测试件方法），动态校准仅适用于该类型测试件的已验证频率范围。 与频率相关的校正因子适用于校正高达动态力范围 10% 的动态力测量误差。 通过使用这样的校正因子，实际测试样本动态力测量误差将减少到小于动态力范围的1%。 对于方法 B（合规包络法），动态校准适用于合规性位于两个 DCD 之间的测试件验证的测试频率范围。 没有适用的校正因子，因为方法 B 不允许动态力测量误差超过动态力范围的 1%。 注：附录 A 提供了有关何时应使用 ISO 4965 本部分中描述的方法重新校准系统的指南。 [外文原描述]： ISO 4965-1:2012 describes two methods for determining the relationship between the dynamic force range applied to a test-piece in a uniaxial, sinusoidal, constant amplitude test and the force range indicated by the testing system. These methods are applicable to dynamic testing systems operating away from system resonant frequencies and are relevant to testing systems where the dynamic force measurement errors are either unknown or where they are expected to exceed 1 % of the applied force range. The dynamic force measurement errors are determined by comparison of the peak forces indicated by the dynamic testing system with those measured by the strain gauged dynamic calibration device (DCD). This DCD has previously undergone static calibration against the testing system indicator. For Method A (Replica test-piece method) , the dynamic calibration is applicable over the validated range of frequencies for that type of test-piece only. A frequency-dependent correction factor is applicable for the correction of dynamic force measurement errors of up to 10 % of dynamic force range. By using such a correction factor, the actual test specimen dynamic force measurement error will be reduced to less than 1 % of the dynamic force range. For Method B (Compliance envelope method) , the dynamic calibration is applicable over the range of test frequencies validated for test-pieces whose compliance lies between those of the two DCDs. No correction factor is applicable, as Method B does not permit dynamic force measurement errors above 1 % of the dynamic force range.