Method and device for measuring dynamic stiffness of resilient element

Abstract

The invention relates to a method and a device for measuring the dynamic stiffness of a resilient element. The dynamic stiffness of a resilient element is measured using an excitation point measurement method in ISO 10846-5. First, the dynamic stiffness k11 of an excitation point is obtained. Then, the test system equivalent vibration mass inertia stiffness Omega<2>m1 and the test system equivalent support stiffness ki are measured, and the dynamic stiffness k21 of the resilient element after modification is calculated according to the formula: k21=k11+Omega<2>m1-ki. In addition to devices adopted in the excitation point measurement method in ISO 10846-5, the device comprises a single-frequency resonant signal generator (101), a power amplifier (102), an isolation spring upper positioning plate (107), an isolation spring lower positioning plate (108), a force sensor (109), an acceleration sensor (110), and a signal conditioning, collecting and processing system (112). Compared with the prior art, through second measurement carried out on the basis of first measurement, the accuracy of the dynamic stiffness measurement result and the applicable frequency range are improved effectively.

Description

technical field [0001] The invention relates to any mechanical engineering field including the technical field of railway tracks, and proposes a testing method and a testing device for improving the frequency range and measurement accuracy of dynamic stiffness of an elastic unit. Background technique [0002] Because the complex elastic unit of the track generally contains not only elasticity but also mass and damping, etc., the dynamic stiffness includes not only the direct stiffness but also the cross stiffness, which can be expressed in the form of a matrix, such as figure 1 shown. The basic principle of measuring the dynamic stiffness 1 of the elastic unit is to obtain the dynamic stiffness of the elastic unit by measuring the input or output force F and the input or output displacement u (or velocity or acceleration). [0003] The current general elastic element dynamic stiffness measurement method and test device are in accordance with the international standard ISO10...

AI Technical Summary

Problems solved by technology

[0015] 1. At high frequencies, the inertial force of the equivalent vibrating mass of the entire test system increases relative to the elastic force of the tested elastic unit, resulting in the inability to obtain accurate stiffness transfer results at the input and output ends of the elastic element;

[0016] 2. When the test frequency is close to or higher than the combined natural frequency of the equivalent participatory mass and the stiffness of the entire test system, since the inertial force of the equivalent participatory mass dominates, the resonance of the entire test system makes it impossible to accurately measure the entire fastener system Dynamic stiffness of

[0019] As far as the fastener system is concerned, its design frequency range is much higher than 30Hz, so the effectiveness of the excitation point measurement method is greatly reduced when it is applied to a low stiffness (<15kN / mm) fastener system. The present invention aims to improve the accuracy of the measurement results Frequency Range and Accuracy

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