Introduction
Chapter 1: Introduction
1.5 Active constrained layer damping (ACLD)
1.4.3 Comparative studies on the control capabilities of PFC actuators
Azzouz et al. (2001) performed a comparative study on the control capabilities of MFC and traditional PZT-5A actuators in control of cantilever square and triangular plates. Nguyen and Kornamann (2006) carried out a comparative study on the capabilities of AFC, MFC and conventional PZT actuators in control of vibration of a cantilever beam. Raja et al. (2011) studied the control of shape and vibration of laminated plates using MFC and SAFC actuators. Gopinath et al. (2011a, 2011b) investigated the active control of aero-elastic flutter of a composite plate using the patches of shear mode (SAFC) and extension mode (MFC) PFC actuators. Zhang et al. (2015, 2016) carried out a comparative study on the control capabilities of d33 and d31 MFCs in control of composite and isotropic plates. Kumar et al. (2017) investigated the damping capabilities of four kinds of cylindrically orthotropic PFC laminate actuators in the active vibration control of isotropic annular plates by proposing numerical method for optimal configuration of patches corresponding to the mode of vibration.
Chapter 1: Introduction
(Arafa and Baz, 2000a; Arafa and Baz, 2000b; Baz and Tempia, 2004), etc. Among all these damping arrangements, the most popular one is the ACLD arrangement as it is widely used in aircraft, naval and automobile industries (Herdic et al., 2005;
Kwak et al., 1999; William, 1998). The concept of ACLD treatment was proposed by Baz and Ro (1993). In this proposition of ACLD treatment (Baz and Ro, (1993), a viscoelastic layer is sandwiched between two piezoelectric layers. The piezoelectric layers are utilised as the sensor and actuator layers through a controller to control the transverse shear deformation of the constrained viscoelastic layer for having enhanced damping in the overall structure. Instead of using two piezoelectric layers, Shen (1993, 1994) utilised one piezoelectric layer to constrain the viscoelastic layer, while the control activities of the piezoelectric constraining layer were regulated by a controller and a point-sensor.
1.5.1 Experimental investigations of ACLD
Azvine et al. (1995) presented another arrangement of ACLD treatment where the piezoelectric layer was attached to the metallic constraining layer instead of using the piezoelectric layer as the constraining layer. In the early stage of evolution of ACLD treatment, its utility as a potential damping device was substantiated through a comparative study of the available active, passive and hybrid damping treatments (Chen and Baz, 1996, Tomlinson, 1996, Veley and Rao, 1996). Baz and Ro (1996) experimentally investigated the vibration characteristics of flat plates integrated with a layer of ACLD treatment and reported superior performance of ACLD treatment than pure passive damping. Chantalakhana and Stanway (2000) experimentally investigated the vibration damping of a fully clamped plate integrated with a layer of ACLD treatment. Liu et al. (2004) experimentally demonstrated the partial ACLD treatment of plates using robust H controller and compared the efficiency of ACLD treatment with that of the pure passive damping.
Ko et al. (2004) experimentally investigated the effectiveness of ACLD treatment for control of arc-type cantilever composite shells and compared the damping capacity of the ACLD treatment with that of the pure passive treatment. Shi et al. (2004) presented the experimental results for controlled and uncontrolled impulse responses at the free tip of a cantilever beam integrated with the ACLD treatment.
Vasques et al. (2006) presented an experimental study on the arbitrary ACLD treatment of composite beams.
1.5.2 Analytical and numerical investigations of ACLD
Baz (1997) also studied the vibration characteristics of cantilever beams integrated with ACLD treatment and demonstrated the suitability of this active-passive damping treatment. Ray and Baz (1997) analyzed the energy dissipation characteristics of ACLD treatment of plates to determine the optimal size and control gains of the treatment. Shen (1997) presented a study on the active control of vibration of shells using ACLD treatment. Park and Baz (1999) and Gandhi and Munsky (2000) used different control strategies for achieving superior damping capacity of the ACLD treatment.
Baz and Chen (2000) used the ACLD treatment for control of axisymmetric vibration of cylindrical shells and reported its (ACLD) effectiveness in comparison to the passive viscoelastic damping. A similar study on control of cylindrical shells using ACLD treatment was carried out by Ray et al. (2001). Chattopadhyay et al.
(2001) presented the influences of the number of piezoelectric actuators and their locations in the segmented ACLD treatment of composite plates. Saravanan et al.
(2001) performed a semi-analytical FE analysis of ALCD of cylindrical shells of revolution and addressed the effects of axial and circumferential mode numbers, feedback factor, length to radius ratio, radius to thickness ratio of the shell, percentage area of the shell covered with collocated piezoelectric sensors/actuators and axial location of collocated sensors/actuators on the damping ratio of cylindrical shells of revolution. Lim et al. (2002) developed an FE model for the ACLD treatment of cantilever isotropic plates and addressed through a time-domain analysis that the damping in the ACLD treatment is better than that in the passive or active treatment. Batra and Geng (2002) reported that the energy of electrical deformations of shear mode PZT actuators was more than that for extension mode actuators in the ACLD treatment of thick laminated plates. Balamurugan and Narayanan (2002) used LQR optimal control strategy to activate the piezoelectric constraining layer for the ACLD treatment of beams and made an assessment of damping capability of the treatment.
Chattopadhyay et al. (2002) carried out a study to enhance the aeromechanical stability of composite rotor blades using ACLD treatment. Ro and Baz (2002) used the modal strain energy method (MSE) and self-sensing ACLD networks and addressed the optimal locations of ACLD patches in control of vibration of plates. Sun and Tong (2003) investigated the effect of debonding of
Chapter 1: Introduction
ACLD patches on its (ACLD) efficiency in the control of beams. Ray and Reddy (2004a) presented the optimal size and locations of ACLD patches over the surface of a laminated circular cylindrical shell.
Gao and Liao (2005) studied the effects of control gain, size and location of piezoelectric actuators on the modal frequencies and modal loss factors of a simply- supported beam integrated with self-sensing ACLD treatment. Ray and Reddy (2005) and Ray and Mallik (2005) investigated the performance of an extension mode 1-3 PFC as the material for constraining layer for ACLD treatment of laminated composite plates and shells. Sharnappa et al. (2007) studied the ACLD treatment of composite beam under thermal environment and addressed the effects of fiber orientation and temperature on the natural frequency and damping of the system for different boundary conditions. Liu et al. (2007) investigated the vibration characteristics of rotating cantilever plates integrated with ACLD treatment and found faster increase of the higher natural frequencies than that for lower natural frequencies as the rotating speed increases. Ray and Pradhan (2007) and Ray and Batra (2007a) investigated the performance of vertically reinforced 1-3 PFC layer as the constraining layer for ACLD treatment of laminated beams and FG plates. Li et al. (2008) studied the ACLD treatment of beams and found that the maximum value of required control voltage can be reduced by increasing the number of ACLD patches.
Providakis et al. (2008) compared the ACLD treatment with the active damping (AD) treatment based on the electromechanical impedance approach.
Saini et al. (2008) addressed the optimal locations of MFC patches for ACLD treatment of first three modes of vibration of thin shells. Panda and Ray (2008, 2009a, 2009b) investigated the performance of horizontally reinforced (Mallik and Ray, 2003) and vertically/obliquely reinforced (Smith and Auld, 1991) 1-3 PFC actuators for ACLD treatment of FG plates. Kumar and Singh (2009) studied the partial ACLD treatment of beams and addressed the effects of control gain, viscoelastic layer thickness, coverage of the treatment and location of ACLD patches on the system loss factors. Yuan et al. (2010) addressed the potential of semi-analytical method over the FEM in the analysis of vibration of ACLD treated circular cylindrical shells. Zheng et al. (2011) analyzed natural frequencies, loss factors and frequency responses of cylindrical shells integrated with ACLD treatment. Kumar and Singh (2012) experimentally investigated the bending and twisting vibration characteristics of a curved panel integrated with ACLD patches.
Suresh Kumar and Ray (2012) developed a three-dimensional model of a sandwich plate integrated with ACLD treatment and studied the performance of vertically/obliquely reinforced 1-3 PFC as the material of active constraining layer.
Li and Narita (2013) presented the ACLD treatment of laminated composite plates for arbitrary boundary conditions. Zhang and Zheng (2014) studied the partial ACLD treatment of plates by developing a hybrid controller where it is demonstrated that the controller effectively reduces the displacement-amplitude through the combined feed forward and feed backward control actions. Ni et al.
(2013) investigated the active-passive damping in shells of revolution for ACLD treatment according to a specified control strategy and reported that the ACLD treatment is more effective at low frequency of vibration. Aravinda Kumar et al.
(2016) presented nonlinear frequency responses of heated FG plates integrated with the ACLD treatment where the active constraining layer is made of an extension mode 1-3 PFC. By developing a three-dimensional FE model, Kundalwal and Ray (2016) investigated the ACLD treatment of smart fuzzy fiber reinforced composite (FFRC) plates. Li et al. (2016) studied the suppression of random vibration of laminated composite rectangular plates using ACLD treatment and 1-3 PFC for the material of active constraining layer. Lu et al. (2017) presented a theoretical study on the partial ACLD treatment for control of vibration of thin plates at low frequency, and the corresponding observations have also been verified experimentally.