Magnetorheological damper having parallel normally-open holes and methods for calculating zero-field damping coefficient, on-field damping coefficient and damping force of magnetorheological damper

Abstract

The invention discloses a magnetorheological damper having parallel normally-open holes and methods for calculating zero-field damping coefficient, on-field damping coefficient and damping force of the magnetorheological damper. The magnetorheological damper comprises a cylinder, a piston is slidably disposed inside the cylinder, a piston rod is disposed at one end of the piston, the piston rod extends out of one end opening of the cylinder, the piston comprises a core, the sidewall of the core is provided with at least one circular groove in a recessed manner, an excitation coil is wound in each circular groove, a magnetic-shielding protective ring covers the outside of each excitation coil, and magnetic permeability protective rings cover the sidewall of the core, a gap between the magnetic-shielding protective rings and magnetic permeability protective rings and the inner wall of the cylinder forms a circular damping passage in the axial direction, and the core is provided with at least one normally open hole. Under semi-active control of structural vibration, damping force can be controlled for the magnetorheological damper just by switching zero current and maximum current according to a switch control strategy, establishment and solution of a complex reverse mechanical model are avoided, and the control process is simple and practical.

Description

Technical field [0001] The invention relates to a magnetorheological damper with parallel constant through holes and a method for obtaining its zero-field damping coefficient, field damping coefficient and damping force, belonging to the technical field of structural magnetorheological vibration semi-active control. Background technique [0002] Magnetorheological fluid is a kind of smart material that is sensitive to magnetic field. As the external magnetic field is loaded or withdrawn, the magnetorheological fluid transforms between non-Newtonian fluid and Newtonian fluid. This conversion is reversible and continuous. Magnetorheological fluid has high shear yield strength and fast response. Magnetorheological damper based on it is an ideal variable damping device, which is widely used in structural vibration in vehicle engineering, weapon systems, civil engineering, aerospace and other fields Semi-active control. [0003] The existing magnetorheological damper is characterized i...

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Problems solved by technology

[0009] The purpose of the present invention is to overcome the problem that the reverse mechanical model and control process of the existing magneto-rheological damper are complicated and difficult to apply to engineering practice, and propose a parallel normally through-hole magneto-rheological damper with parallel normally When the magneto-rheological damper with the through hole is zero, the magneto-rheological fluid flows through the through-hole and the annular damping channel, realizing the minimum damping force, which corresponds to the zero-field damping force coefficient. When the current is loaded to the maximum value, the annular damping channel is blocked by the rheological effect of the magnetorheological fluid and acts as a pressure limiting valve. Before the magnetorheological fluid yields, the magnetorheological fluid only flows through the normal through hole. The maximum damping force is achieved, which corresponds to the field damping force coefficient. Therefore, the magnetorheological damper only needs to switch between zero current and maximum current value according to the switch control strategy, so as to avoid the establishment of complex reverse mechanics The model and the solution to the model greatly simplify the control process

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