Equivalence between exponential stabilization and observability inequality for magnetic effected piezoelectric beams with time-varying delay and time-dependent weights

<p style='text-indent:20px;'>This paper is concerned with system of magnetic effected piezoelectric beams interior time-varying delay and time-dependent weights, in which the beam clamped at two side points subject to a single distributed state feedback controller delay. Under appropriate assumptions on term we obtain exponential stability estimates by using multiplicative technique, prove equivalence between stabilization observability.</p>