High-frequency fatigue testing machine dynamic load error compensation method

Abstract

A high-frequency fatigue testing machine dynamic load error compensation method includes the following steps: 1) establishing a three-freedom-degree vibration mechanical model having the system with damping, and analyzing relevant factors affecting a dynamic load error; 2) determining a key factor affecting the dynamic load error; 3) making a pasted strain piece of a middle section of a calibration rod into a calibration sensor, and calculating the stiffness by using a finite element method; 4) taking a calibration sensor with known stiffness, fixing the upper end to a testing machine, allowing the lower end to press a standard force sensor, applying a static load, and calibrating by the standard force sensor; 5) calculating the difference between the amplitude of the calibration sensor and the amplitude of the force measuring sensor, and recording the corresponding calibration sensor stiffness; 6) changing the calibration sensors with different stiffness, repeating the step 4) and the step 5), and thus obtaining a relation curve of the error and the sensor stiffness; and 7) carrying out error compensation on a corresponding dynamic load measurement value by the calculated error value. The measuring accuracy of the fatigue testing machine dynamic load is effectively improved.

Description

technical field [0001] The invention relates to the field of error compensation, in particular to an error compensation method for dynamic load of a high-frequency fatigue testing machine. Background technique [0002] Fatigue testing machine is a standard equipment for fatigue testing. Whether its performance is good or bad directly affects the accuracy and reliability of fatigue testing results. The dynamic load error of fatigue testing machine is a very important technical indicator. At present, for the dynamic load calibration of the high-frequency fatigue testing machine, most of the static calibration methods are used. In the static state, the sensor can obtain high accuracy in the calibration, but in the dynamic test process, due to the upper fixture and the method The inertial force generated by the blue mass will make the measured value of the load cell and the real force value of the test piece not equal, resulting in a large measurement error. [0003] In order t...

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Problems solved by technology

[0004] In order to overcome the shortcomings of the existing fatigue testing machine static calibration method and the dynamic load error theoretical expression compensation method for the poor dynamic load error compensation effect, the present invention provides a method with good error compensation effect and effectively improves the dynamic load measurement accuracy of the fatigue testing machine Dynamic Load Error Compensation Method for High Frequency Fatigue Testing Machine

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