Small device for load bending fatigue testing and method

Abstract

The invention discloses a small device for load bending fatigue testing and a method. The device comprises a base, a gantry, a linear motor module, a linear motor module bracket, a load sensor, a thrust rod guide wheel assembly, a thrust rod, a specimen fixed end clamp right support table, a specimen cantilever end clamp assembly, a displacement sensor test connective rod, a displacement sensor, adisplacement sensor bracket, a fatigue specimen, a specimen fixed end clamp assembly, an environmental chamber, a specimen fixed end clamp left support table, and control system. The small device forload bending fatigue testing and the method provided by the invention can realize fatigue testing of stress control, strain control, and stress / strain hybrid control, and achieve a bending fatigue performance testing with a stress ratio greater than zero, equal to zero, or less than zero. The advantages of the device are reasonable in structure design, complete in function, and convenient in operation.

Description

technical field [0001] The invention belongs to the technical field of fatigue testing, and in particular relates to a small-load bending fatigue testing device and method. Background technique [0002] Bending fatigue failure of mechanical parts due to cyclic bending stress or strain is one of the common failure modes. Using a bending fatigue testing machine to perform bending fatigue tests on parts, and to establish a relationship curve (S-N curve) between the maximum stress or strain and its failure cycle is an important method for evaluating the bending fatigue life of parts and ensuring the safety of equipment personnel. [0003] According to the number of failure cycles and the bending stress level of the component, bending fatigue can be divided into low cycle bending fatigue and high cycle bending fatigue. The fatigue of many parts under the action of variable amplitude cyclic bending stress is neither pure high cycle fatigue nor high cycle fatigue. Pure low cycle f...

AI Technical Summary

Problems solved by technology

Existing bending fatigue testing machines mostly use eccentric wheel or weight loading as the driving device. The defect of this device is that it can only perform strain control fatigue test, that is, low-cycle bending fatigue test, and the test accuracy of this loading method is poor, so it cannot pass The decrease of the bending resistance of the sample determines when fatigue cracks occur in the parts; the three-point bending / four-point bending fatigue test method cannot realize the bending fatigue performance test under the condition that the stress ratio is equal to or less than zero, and the bending frequency during the test is relatively low. Low, long test time; the disadvantage of using a hydraulic cylinder as a driving device is that fatigue testing cannot be performed under loading conditions lower than 1000N

For thin-walled parts with a bending stress of less than 1000N and a stress ratio of less than zero, traditional testing methods cannot perform bending fatigue performance tests

Images