Options of Execution of Drives in the Device of Seismo Platform

Authors:  
Rubric:     Theoretical and experimental studies   
Key words: seismic impact, drive, seismic platform, linear electric motor
Annotation:
To provide reciprocating motion or other type of movement in modern seismic platforms, various types of linear actuators are widely used.
At the moment, an urgent task is to create a seismic platform that allows you to reproduce seismic loads in a wide range of vibration frequencies from 0.2 to 100 Hz, which allows you to simulate all the dangerous frequencies of real impacts.
The disadvantage of modern seismic platforms is a limited range of oscillation frequencies due to the complexity of drives, which are to provide long-period and high-frequency oscillations typical of real accelerograms. The correct choice of a drive for implementing reciprocating motion is an important task in designing and manufacturing seismic platforms, both from technical and economic parts of view. These questions are considered in the paper.
The comparative analysis of linear drives is given. Hydraulic, pneumatic, Electromechanical systems of linear displacement, as well as linear electric machines as a separate class of electric machines are considered. The peculiarities of realization of the linear actuators in the design of modern seismic platforms, for example seismic platforms protected by the patent [7]. To implement the method of separation of impacts in modeling seismic vibrations, the authors propose a two-level seismic platform design. Using this approach, the velocity pulse is transmitted through the upper drive, The lower drive will provide high-frequency oscillations. To ensure a wide range of oscillation one of the variants of a system of linear actuators to implement the specifid effcts is a combination of high frequency hydraulic actuator and linear electric machines for the implementation of low-frequency vibrations or residual offets.
The use of this combination of drives will reduce material costs when implementing such a system on a fully hydraulic drive, without losing the accuracy of the tests.