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In this article, the physical and Geometrical effective parameters on free vibration and Force impact a three-layer sandwich plate in the middle layer with magneto rheological (core) Under cross-shot with low speed is investigated. The first natural frequency and loss factor of comparable modal for the first four vibrative modes for Core thickness, magnetic fields and different sheet’s geometrical parameters, is founded. The MR material shows variations in the rheological properties when subjected to varying magnetic fields. These materials with fast response time (in milliseconds) Through a detailed with variation in Magnetic field can be controlled. The governing equations of motion were obtained using Hamilton̕s principle. The results were obtained by the systematic analytical solution. Using the two degrees of freedom mass-spring model, the contact force function can be obtained analytically. The obtained natural frequency from eigen value problem, was used for calculating of equivalent mass of the plate in spring mass model. The results show that with systematic variation of magnetic field and with increasing the ratio of core thickness to the layer thickness and also with increasing the ratio of length to the whole of sheet thickness, we can in order, the stiffness, structural loss factor coefficient and maximum contact force can be changed and controlled.