GB/T 25917.1-2019 English PDFUS$344.00 · In stock
Delivery: <= 3 days. True-PDF full-copy in English will be manually translated and delivered via email. GB/T 25917.1-2019: Uniaxial fatigue testing systems -- Part 1: Calibration of dynamic force Status: Valid GB/T 25917.1: Historical versions
Basic dataStandard ID: GB/T 25917.1-2019 (GB/T25917.1-2019)Description (Translated English): Uniaxial fatigue testing systems -- Part 1: Calibration of dynamic force Sector / Industry: National Standard (Recommended) Classification of Chinese Standard: N71 Classification of International Standard: 19.060; 77.040.01 Word Count Estimation: 18,112 Date of Issue: 2019-10-18 Date of Implementation: 2020-05-01 Issuing agency(ies): State Administration for Market Regulation, China National Standardization Administration GB/T 25917.1-2019: Uniaxial fatigue testing systems -- Part 1: Calibration of dynamic force---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.Uniaxial fatigue testing systems--Part 1. Calibration of dynamic force ICS 19.060; 77.040.10 N71 National Standards of People's Republic of China Replaces GB/T 25917-2010 Uniaxial fatigue test system Part 1. Dynamic force calibration (ISO 4965-1..2012, Metalicmaterials-Dynamicforcecalibrationfor uniaxialfatiguetesting-Part 1. Testingsystem, IDT) Published on October 18,.2019 2020-05-01 implementation State Administration of Market Supervision Published by China National Standardization Administration ContentsForeword III Introduction IV 1 Scope 1 2 Normative references 1 3 Terms, definitions and symbols 1 4 General requirements 3 4.1 Temperature 3 4.2 Dynamic Test System 3 4.2.1 Static Calibration 3 4.2.2 Frequency Calibration 3 4.2.3 Dynamic force range 3 4.2.4 Load chain 4 4.2.5 Installation of DCD 4 4.2.6 Dynamic test system 4 4.2.7 DCD Instrument 4 5 Procedure 4 5.1 Initial inspection 4 5.1.1 System Bandwidth 4 5.1.2 Repeatability of afterburner 5 5.2 Calibration procedure 6 5.2.1 Static Calibration of DCD 6 5.2.2 Dynamic calibration of force indication of test system 6 6 Calculation of results 7 6.1 Calculating DCD force and measuring force range 7 6.2 Equivalent sample --- Method A 7 6.3 Flexibility envelope--Method B 7 7 Report 9 7.1 General information 9 7.2 Results of dynamic force calibration 9 7.3 Recalibration 9 Appendix A (Normative) User Recalibration Guide 10 Appendix B (Informative) Guidelines for Estimating Instrument Bandwidth of Test Systems 11 References 12ForewordGB/T 25917 `` Uniaxial Fatigue Test System '' is divided into the following two parts. --- Part 1. Dynamic force calibration; --- Part 2. Instruments for dynamic calibration devices. This part is the first part of GB/T 25917. This section is drafted in accordance with the rules given in GB/T 1.1-2009. This section replaces GB/T 25917-2010 "Dynamic Force Calibration of Axial Afterburner Fatigue Testing Machine", compared with GB/T 25917-2010 The technical changes are as follows. --- Added two calibration methods, Method A and Method B (see Chapter 1); --- Modified terms, definitions and symbols (see Chapter 3, Chapter 3 of the.2010 edition); --- Added requirements for static force calibration and frequency calibration (see Chapter 4); --- Added Method A and Method B test and calculation methods (see Chapters 5 and 6); --- Deleted the calibration rod and its calibration (see Chapter 5 and Chapter 8 of the.2010 edition); --- Deleted the performance evaluation and calibration curve of the testing machine (see Chapter 10 and Chapter 11 of the.2010 edition); --- Added Appendix A and Appendix B, deleted Appendix A and Appendix B of the.2010 version (see Appendix A and Appendix B, the.2010 version (Appendix A, Appendix B). This section uses the translation method equivalent to ISO 4965-1..2012 "Dynamic Force Calibration of Uniaxial Fatigue Tests on Metal Materials Part 1 Points. Test System. The Chinese documents that have a consistent correspondence with the international documents referenced normatively in this section are as follows. --- GB/T 16825.1-2008 Inspection of static uniaxial testing machines-Part 1. Force measurement system of tensile and/or compression testing machines System inspection and calibration (ISO 7500-1..2004, IDT); --- GB/T 25917.2-2019 Uniaxial fatigue test system Part 2. Instrument for dynamic calibration device (ISO 4965-2. 2012, IDT). The following editorial changes have been made in this section. --- In keeping with the existing standard series, the standard name was changed to "Uniaxial Fatigue Test System Part 1. Dynamic Force Calibration". This section is proposed by China Machinery Industry Federation. This section is under the jurisdiction of the National Testing Machine Standardization Technical Committee (SAC/TC122). This section was drafted by. China Machine Test Equipment Co., Ltd., Wuxi Metrology and Testing Institute, Guangzhou University, Shenzhen Wantest Test Equipment Co., Ltd., China Aviation Industry Corporation Beijing Great Wall Measurement Testing Technology Research Institute, Shanghai Hualong Testing Instrument Co., Ltd., Jinan Xinguang Testing Machine Manufacturing Co., Ltd., Suzhou Tuobo Machinery Equipment Co., Ltd., Suzhou Dongling Vibration Test Instrument Co., Ltd., Jilin University. The main drafters of this section. Wang Xuefeng, Zhang Shenghai, Xu Zhonggen, An Jianping, Tian Feng, Lu Dan, Wang Jianguo, Ye Jianrong, Tong Ningke, Zhang Jianhai, Zhao Hongwei. The previous versions of the standards replaced by this section are. --- GB/T 25917-2010.IntroductionIn the dynamic test, the test force (Ft) on the sample and the indicated force (Fi) of the test system have significant differences. Dynamic error comes from The inertial force acting on the force sensor and the dynamic error of the electronic equipment in the force display system. The inertia force is equal to the mass of the fixture Between the force sensor and the specimen) multiplied by its local acceleration. Therefore, it is related to the following factors. a) motion amplitude; b) exercise frequency; c) Fixture quality. Correspondingly, the amplitude of the motion depends on the magnitude of the applied force and the mechanical configuration of the test system, including the compliance of the load chain, the specimen, the restraint structure And installation foundation. For a given frequency within a given range of force values, different combinations of flexibility values will result in different amplitudes of motion [clamp The fixture with a very flexible specimen may move in the opposite direction (inverted) toward the same fixture holding a very rigid specimen]. For the purposes of this part of GB/T 25917, there is a linear relationship between the displacement of the actuator and the displacement of the applied force. The calculated correction factor can dynamically calibrate the force measurement system within 1% of the applied force. Use method B and both have Dynamic calibration device (DCD) with different flexibility can dynamically calibrate the force measurement system in the range of 1% of the applied force, but the condition is The compliance of the test sample is between those of the two DCDs. Method A (equivalent sample method) uses DCD with a correction factor generated by calculation to calibrate the dynamic test system. Within the range of force, the allowed error after correction is 10%. DCD has the same flexibility and quality as the test sample, and the entire loading chain The same as the actual test. Before starting a series of dynamic tests, determine the indicated force range (ΔFi) and Correction factor related to test force range (ΔFt). This factor can be used to modify the test results or to improve the test force. Adjust to reduce the dynamic error to less than 1%. This correction factor depends on the test frequency, so the entire test frequency must be determined in advance Range. Method B (flexibility envelope method) uses two DCDs with different flexibility to calibrate the test system using multiple forms of samples. low The flexibility DCD should have a lower flexibility than the test sample, and the high flexibility DCD should have a higher flexibility than the test sample. Test system The dynamic envelope of the tested sample about compliance-frequency, the dynamic error is kept within 1% of the applied force range. This assumes that with any Compared to the compliance of a DCD, the compliance of the loading chain is very small. If this is not the case, if the test machine has multiple compliance values for the load chain, Perform additional calibration. Uniaxial fatigue test system Part 1. Dynamic force calibration1 ScopeThis part of GB/T 25917 describes two ways to determine how a specimen can be tested in uniaxial, sinusoidal, and constant amplitude tests. The method of the relationship between the dynamic force range (ΔFt) and the test system force value display range (ΔFi) (see the introduction). These methods can avoid the resonance frequency of the system when the dynamic test system is working. The range is expected to exceed 1% of the test system. The dynamic force measurement error is obtained by comparing the peak value of the force displayed by the dynamic force test system with the dynamic force calibration device attached with a resistance strain gauge. (DCD) measurement. Perform static calibration on the displayed value of the DCD test system in advance (see 5.2.1). Method A (equivalent to the sample method) dynamic calibration is only applicable to the valid frequency range confirmed from the sample. Frequency-based repair The positive factor is suitable for correction when the dynamic force measurement error is up to 10% of the dynamic force range. Using this correction factor will make the actual test The dynamic force measurement error of the sample is reduced to the extent of less than 1% of the dynamic force range. Method B (flexibility envelope method) dynamic calibration is applicable to the effective frequency range of samples with flexibility between two sets of DCD. because Method B does not allow the dynamic force measurement error to exceed 1% of the dynamic force range, so method B does not apply a correction factor. NOTE. Appendix A provides guidelines for recalibrating the testing machine using the methods described in this section.2 Normative referencesThe following documents are essential for the application of this document. For dated references, only the dated version applies to this article Pieces. For undated references, the latest version (including all amendments) applies to this document. ISO 4965-2 Dynamic stress calibration of uniaxial fatigue tests on metallic materials. Part 2. Dynamic calibration device (DCD) [Metalic materials-Dynamicforcecalibrationforuniaxialfatiguetesting-Part 2. Dynamiccalibrationdevice (DCD) instrumentation] ISO 7500-1 Inspection of static uniaxial testing machines for metallic materials. Part 1. Force measurement systems for tensile and/or compression testing machines Inspection and Calibration (Metalicmaterials-Verificationofstaticuniaxialtestingmachines-Part 1. Tension / compressiontestingmachines-Verificationandcalibrationoftheforce-measuringsystem) 3 terms, definitions and symbols The following terms, definitions and symbols apply to this document. Figure 1 shows a schematic of the calibration process. Figure 1 Schematic diagram of GB/T 25917 calibration method 3.1 Correction factor At the same frequency, the ratio of the dynamic force range determined by DCD (ΔFDCD) to the dynamic force range displayed by the test system (ΔFi). 3.2 Dynamiccalibrationdevice; DCD For method A, it is the equivalent sample of the strain type sample (or for method B, it is the detection device), it has the same Quality and compliance. For method B, compliance is known. 3.3 DCD Force DCDforce FDCD The force measured by DCD is calculated by iDCD after static calibration of the testing machine. Note. See equations (2) and (3). 3.4 DCD display value DCDindication iDCD The output value of the DCD instrument. Note. DCD instruments need to be calibrated according to electrical standards in advance. The display of DCD instruments is electrical units, such as mV or mV/V. 3.5 DCD instrument DCD instrumentation Includes output modulation circuit and display of strain gauge bridge, used to connect dynamic calibration equipment. Note. The instrument for dynamic calibration device can also provide the power supply voltage of the dynamic calibration device. At this time, the voltage is displayed in the ratio of mV/V. Output value. 3.6 Dynamic force range ΔF Under cyclic conditions, the difference between the peak value and the trough value of the force. 3.7 Dynamic testing system Consists of an actuator, a load frame, a load chain, and an instrument used to perform cyclic tests.It can display the peak value of the applied force and the Test system for trough value. 3.8 Displayedforce Fi The force value measured and displayed by the force sensor of the dynamic test system under dynamic and static conditions. Calibration. 3.9 Indication error ei The difference between the force range displayed by the test system device and the DCD device is expressed as a percentage of the DCD force range. 3.10 Loadtrain In the dynamic test system, all components except the sample/DCD that transmit the force value between the actuator and the load frame, including This includes force sensors, connectors, clamps, and other fixtures.4 General requirements4.1 Temperature Record the ambient temperature during the dynamic force calibration of the uniaxial fatigue tester. Calibration should be performed at a constant ambient temperature. Attention should be paid to avoid DCD from airflow and direct sunlight. 4.2 Dynamic test system 4.2.1 Static Calibration The dynamic test system shall be static force calibrated according to ISO 7500-1, reaching level 1 or better. 4.2.2 Frequency Calibration Except those frequency points that affect the measurement accuracy due to system resonance, the dynamic test system should be in all frequency ranges involved in the test For dynamic calibration, see 5.1.1 for details. The amplitude error should be kept less than 0.2%. For a bipolar filter, the maximum test frequency It should not exceed 25% of the test system instrument bandwidth (see Appendix B), or for single-pole filters, the maximum test frequency should not exceed 6%. Filtering the signal of the measured force will directly affect the dynamic measurement accuracy of the measured force. Therefore, any filtering operation must be performed dynamically. Go ahead. Calibration is valid only for the filters used during calibration. If Method B is used, each DCD must use the same frequency range. The resonance frequency of the system will lead to increased errors in the local area plus. For dual DCD systems, special attention should be paid to identifying such areas.To avoid excessive errors, do not perform in these areas. test. 4.2.3 Dynamic force range The maximum force indication during dynamic calibration should not exceed the force range of the static calibration of the dynamic test system, and maintain the expected force The peak value of the value. The dynamic calibration force range should also be maintained between 10% and 100% of the dynamic force range of each DCD. dynamic There are three forms of force range. through zero, stretch only, and compression only. Tension-only calibration is not valid in compression tests and vice versa. by Zero point calibration is effective in both tensile and compression tests. This part of ISO 4965 requires that if unidirectional is used in dynamic calibration Force range, each test frequency has a linear relationship (although it may be different) between the force mode and the actuator displacement --- prove One way to do this is to record and then plot the position of the actuator during the afterburner as a test machine during or after static calibration A function of the applied force. Note. Inertial error is proportional to acceleration, so it is also proportional to displacement-the linear relationship between force and displacement ensures that inertial error and force are proportional It is proportional, therefore, when authorizing the calibration of the entire unidirectional force range, the force range can be taken as a constant according to a certain proportion. If there is no linear relationship between the applied force and the displacement of the actuator, respond to multiple dynamics before calibrating the dynamic force of the test system. The force range is calibrated. The peak and trough values should be within the working range of the calibration device. For method B, although the dynamic range of the two DCDs can be different, the same frequency range should be used. 4.2.4 Load chain For method A, the load chain should use the same fixtures and accessories as in the actual dynamic test.The DCD should be the same as the test specimen. Same mass, flexibility, and damping (that is, it should be a standard specimen with a resistance strain gauge attached). For method B, use the largest mass used in subsequent tests for calibration, as doing so will cause inertia due to it Maximize errors. Significant changes in load chain compliance can also affect this dynamic error. If the test machine used to test the specimen has a load chain of different flexibility (e.g. rods need to be inserted when using a high temperature furnace), The following steps. --- Determine the compliance of the minimum compliance DCD (C1) (this value should be obtained from the manufacturer); --- Determine the compliance range of the load chain (ΔC = Cmax-Cmin) (this value can be measured under the same force and the same sample as The displacement of the actuator is obtained); --- If ΔC > C1/10, use a double DCD pair test machine to test the load within the maximum flexibility and minimum flexibility calibration range of the load chain. Machine calibration. 4.2.5 Installation of DCD The DCD should be installed in the loading chain in the same position as the actual test specimen. 4.2.6 Dynamic test system The dynamic test system should be able to control the sample and apply repeated cyclic forces, and be able to read this cyclic force. Typically, integrated Or an external waveform generator is used to provide the test system with cyclic waveforms. Measure and record the range or maximum of the obtained test force High level. The dynamic test system should be able to stably provide the highest level of repeated test force throughout the test. Tried throughout During the process, the repeatability of the peak and trough values displayed by the dynamic test system should be kept within 1% of the applied force range in each cycle. The procedures specified in 5.1.2 are used to test whether this requirement is met. 4.2.7 DCD Instrument DCD instruments shall be calibrated in accordance with the requirements of ISO 4965-2. When the instrument is calibrated, the nominal excitation voltage and displayed value should use the voltage Unit, the nominal excitation voltage value shall be used during the calibration of the test system. For instruments that can generate excitation voltage and display “mV/V”, When calibrating the force measurement system of a dynamic test system, use the settings described with the DCD instrument calibration in GB/T 25917.2 the same.5 Procedure5.1 Initial inspection 5.1.1 System bandwidth The purpose of the inspection is to determine the frequency range of the entire inspection test system. One can be used to check the entire measurement system (mechanical and electrical The effect of this method is on dynamic characteristics, that is, using a brittle specimen to perform a fracture test (under displacement control), and recording the sudden change of the force signal. Appendix B provides a method for calculating the bandwidth, and also gives a guide for estimating the bandwidth of the test system instruments. Another technique that can be used to determine the effective frequency range is to complete a frequency sweep, which helps identify those that are due to significant resonances The areas that cause errors, and these areas do not follow the general tre......Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of GB/T 25917.1-2019_English be delivered?Answer: Upon your order, we will start to translate GB/T 25917.1-2019_English as soon as possible, and keep you informed of the progress. The lead time is typically 1 ~ 3 working days. The lengthier the document the longer the lead time.Question 2: Can I share the purchased PDF of GB/T 25917.1-2019_English with my colleagues?Answer: Yes. The purchased PDF of GB/T 25917.1-2019_English will be deemed to be sold to your employer/organization who actually pays for it, including your colleagues and your employer's intranet.Question 3: Does the price include tax/VAT?Answer: Yes. 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