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A fatigue testing method and system for a magneto-rheological shock absorber

A magneto-rheological shock absorber and fatigue testing technology, applied in the field of fatigue testing, can solve problems such as oxidation fatigue, failure to meet the functional requirements of magnetorheological shock absorbers, and lack of basis

Active Publication Date: 2020-06-19
TSINGHUA UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] Fatigue life is an index that must be investigated in the practical application of magneto-rheological shock absorbers. In addition to considering from the perspective of ordinary shock absorbers, there are also unique aspects that need to be considered: 1. The damping force of the magnetorheological shock absorber is adjusted by loading different currents. There is no basis for how much current is loaded in the fatigue test.
If no current is applied, it obviously does not meet the functional requirements of the magneto-rheological shock absorber, and it is not enough to examine the life of the magnetorheological shock absorber; The reliability test requirements are too high, and fatigue problems may occur if the required number of tests may not be met
The second is that the magnetorheological fluid is constantly squeezed and rubbed in the damping channel, and the base carrier fluid and suspended soft magnetic particles will cause oxidation fatigue. Therefore, the service life of the magnetorheological fluid itself needs to be investigated
[0004] At present, there is a lack of effective methods to guide the fatigue test of magneto-rheological shock absorbers

Method used

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  • A fatigue testing method and system for a magneto-rheological shock absorber
  • A fatigue testing method and system for a magneto-rheological shock absorber
  • A fatigue testing method and system for a magneto-rheological shock absorber

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Embodiment 1

[0071] figure 1 This is a flow chart of a method for fatigue testing of a magnetorheological shock absorber in Embodiment 1 of the present invention.

[0072] see figure 1 , the magnetorheological shock absorber fatigue test method of the embodiment, including:

[0073] Step S1: Determine the periodic vibration excitation value required for loading the magnetorheological damper.

[0074] The periodic vibration excitation value includes vibration amplitude and vibration frequency.

[0075] Step S2: Determine the range of the cumulative energy dissipated per unit volume.

[0076] The range of the cumulative energy dissipation per unit volume is 1.0×10 6 J / cm 3 ≤W LDE ≤1.0×10 7 J / cm 3 ;W LDE Indicates the cumulative dissipated energy value per unit volume.

[0077] Step S3: Determine the current loading range interval.

[0078] The current value within the current loading range is not greater than the maximum continuous current that the copper wire used in the magnetor...

Embodiment 2

[0099] The fatigue life of magnetorheological fluids has a strong correlation with the cumulative energy dissipated per unit volume. figure 2 It is a graph showing the relationship between the viscosity of the four magnetorheological fluids in Example 2 of the present invention and the cumulative energy dissipated per unit volume. Depend on figure 2 It can be seen that the cumulative energy dissipated per unit volume of bad magnetorheological fluids only reaches 10 5 J / cm 3 When it is even lower, oxidative fatigue will occur, and the zero-field viscosity will increase significantly, and even at zero-field, it will be glue-like and cannot be used continuously. The energy dissipated per unit volume of magnetorheological fluid with good durability reaches 10 7 J / cm 3 can still be used normally.

[0100] Therefore, the cumulative energy dissipation per unit volume of the magnetorheological fluid in the magnetorheological damper is defined as:

[0101]

[0102] Among the...

example 1

[0128] Example 1: Take the vehicle suspension magnetorheological shock absorber 1 as an example, the shock absorber body temperature is 70 ℃, the loading current is 1.0A, the dynamometer diagram under the sinusoidal excitation with the displacement amplitude of ±50mm and the frequency of 1.67Hz is as follows image 3 shown.

[0129] Calculate the area of ​​the dynamometer using the existing area calculation method of the dynamometer That is, the heat dissipated by the shock absorber in one cycle is P=270J. take W LED =2.0×10 6 J / cm 3 , V mrf = 250cm 3 , the expected number of test cycles n∈[1.0×10 6 ,2.0×10 6 ], calculated as: n=1.8519×10 6 , the total time-consuming: time=n / f / 3600=308.039h. n is within the required range, therefore, the magnetorheological damper is loaded with a current of 1.0A, W LED =2.0×10 6 J / cm 3 applied in practice.

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Abstract

The invention discloses a magneto-rheological shock absorber fatigue testing method and system. The method comprises the following steps: selecting any current value in the current range interval as the current testing current value, selecting any unit volume accumulative dissipation energy value in the current dissipation energy range interval as the current unit volume accumulative dissipation energy testing value; at the preset temperature, obtaining an indicator diagram of the magneto-rheological shock absorber according to the current testing current value and the periodic vibration excitation value; determining the single-period dissipation heat according to the indicator diagram; computing the testing period number according to the single-period dissipation heat and the current unitvolume accumulative dissipation energy testing value; judging whether the testing period number is in the preset period range; if the testing period number is located in the preset period range, ending the testing; if the testing period number is not located in the preset period range, re-adjusting the current testing current value and the current unit volume accumulative dissipation energy testing value. The fatigue test of the magneto-rheological shock absorber can be guided, so that the magneto-rheological shock absorber can be well applied in the practice.

Description

technical field [0001] The invention relates to the technical field of fatigue testing, in particular to a method and system for fatigue testing of magnetorheological shock absorbers. Background technique [0002] Magnetorheological fluid is a kind of intelligent material that is sensitive to magnetic field. When there is no external magnetic field, the fluidity is good. Under the action of external magnetic field, the magnetorheological fluid forms a chain bundle along the direction of the magnetic field, showing the characteristics of a solid, and has certain characteristics. shear yield strength. The shear yield strength of magnetorheological fluids increases with the increase of the external magnetic field, so that larger shear stress is required to yield flow. Devices such as dampers and valves are made by utilizing the properties of the magnetorheological fluid, and the viscosity of the magnetorheological fluid is controlled by a magnetic field, thereby realizing the ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01M13/00
CPCG01M13/00
Inventor 危银涛彭志召张进秋
Owner TSINGHUA UNIV