On suppression of chaotic motions of a portal frame structure under non-ideal loading using a magneto-rheological damper

Abstract

We consider chaotic motions of a portal frame structure under non-ideal loading. To suppress this chaotic behavior, a controlling scheme is implemented. The control strategy involves application of two control signals and nonlinear feedforward control to maintain a desired periodic orbit, and state feedback control to bring the system trajectory into the desired periodic orbit. Additionally, the control strategy includes an active magneto-rheological damper to actuate the system. The control force of the damper is a function of the voltage applied in the coil of the damper that is based on the force given by the controller.

Bifurcation Analysis and Chaos Control of a Fractional Order Portal Frame with Nonideal Loading Using Adaptive Sliding Mode Control

“…The system shows its largest Lyapunov exponent (0.08138) when = 0.998 against its integer order Lyapunov exponent of 0.075 [3], confirming that the chaotic oscillations are more in fractional order close to 1 compared to the integer order. Figure 3 shows the 3D phase portraits of the FOPF system.…”

“…We consider the horizontal motion of a portal frame with nonideal excitation [3] as described in Figure 1(a). The portal frame shown in Figure 1(a) is approximated with coupled oscillators [3] as shown in Figure 1(b).…”

“…The portal frame shown in Figure 1(a) is approximated with coupled oscillators [3] as shown in Figure 1(b).…”

“…As described in [3], the parameters of this dynamical system consist of 0 , 1 , the mass and unbalanced mass, l , nl , linear and nonlinear stiffness, l , linear damping, 1 , , displacement and angular displacement, , inertial moment, and , eccentricity of the unbalanced mass. is related to the voltage applied across the armature of the DC motor and is a constant for each model of the DC motor considered.…”

“…These kind of nonideal vibrations systems are considered as major challenge in engineering research [1,2]. Chaotic vibrations of a portal frame system with nonideal loading and its control are presented by Tusset et al [3]. Early researches on nonlinear vibration of frames under support motion do not consider the nonlinear elastic forces [4].…”