Analysis of a Lorentz force based vibration exciter using permanent magnets mounted on a piezoelectric stack

作者：Nandi Arghya^*; Neogy Sumanta; Bhaduri Sankha

来源：Sadhana : Academy Proceedings in Engineering Sciences , 2011, 36(1): 87-107.

DOI：10.1007/s12046-011-0004-x

• Lorentz force
• eddy current
• finite element
• permanent magnet
• vibration
• non-contact exciter

This work presents performance analysis of a Lorentz force based non-contact vibration exciter by mounting a couple of permanent magnets on a piezoelectric stack. A conductor is attached to the structure to be excited and is placed midway between unlike poles of a couple of permanent magnets. The permanent magnets are placed on a piezoelectric stack. This stack, because of its nano-positioning capabilities, can impart an accurate and adjustable harmonic vibratory motion to the couple of permanent magnets. The piezoelectric stack, because of its high stiffness remains uncoupled with the dynamics of the structure. Due to the relative motion between the magnets and the conductor, Lorentz force is generated within the conductor. This Lorentz force is responsible for vibration of the structure in a plane parallel to the pole faces of the magnets. This keeps the magnetic field almost independent of the vibration of the structure and the chance of the structure hitting the magnet during large vibration is totally eliminated. If the amplitude of displacement of the stack is kept constant, the non-contact excitation force in this exciter remains proportional to the excitation frequency. Though use of this exciter eliminates mass (apart from that of the conductor attached to the structure) and stiffness coupling, a known damping term gets added to that of the excited structure.

• 出版日期2011-2