Active vibration control of piezo-laminated cantilever beam

In active vibration control the vibration of a structure is reduced by using opposite directional force to the structure. Now a day‟s active vibration control is frequently being used in aircraft, submarine, automobile, helicopter blade, naval vessel. In this project a smart plate (aluminum plate) with one pair of piezoelectric lamination is used to study the active vibration control. The smart plate consists of rectangular aluminum beam modeled in cantilever configuration with surface bonded piezoelectric patches. The study uses ANSYS-12 software to derive the finite element model of the smart plate. Based on this model, the optimal sensor locations are found and actual smart beam is produced. In this experiment we find a suitable control methodology by which we optimize the controller gain to get more effective vibration control with minimum control input

Dynamic behavior of Sandwich Beam with Piezoelectric layers

Sandwich beams with composite faces sheets and foam core are widely used as lightweight components in many of the industries such as automotive, marine and aerospace applications due to its high bending stiffness and strength combined with low weight. Thus, it is important to gain knowledge of their flexural behavior under static as well as dynamic loads. Although extensive research has been devoted to the flexural behavior of composite laminates in general, the flexural behavior of sandwich structures is quite and obviously different. Several works treating the dynamic flexural behavior of sandwich beams have also confirmed the marked susceptibility of sandwich structures to damage caused by the low velocity impact of foreign objects. Impacts can damage the face sheets, the core material, and the core face interface. The type of damage usually found in the faces is similar to that observed after impacts on monolithic composites. However, the damage initiation thresholds and damage area depend on the properties of the core material and the relationship between the properties of the core and those of the face sheets.The modelling is done for sandwich beam with create volume option with dimensions known in the software

Active Vibration Control of a Smart Cantilever Beam on General Purpose Operating System

All mechanical systems suffer from undesirable vibrations during their operations. Their occurrence is uncontrollable as it depends on various factors. However, for efficient operation of the system, these vibrations have to be controlled within the specified limits. Light weight, rapid and multi-mode control of the vibrating structure is possible by the use of piezoelectric sensors and actuators and feedback control algorithms. In this paper, direct output feedback based active vibration control has been implemented on a cantilever beam using Lead Zirconate-Titanate (PZT) sensors and actuators. Three PZT patches were used, one as the sensor, one as the exciter providing the forced vibrations and the third acting as the actuator that provides an equal but opposite phase vibration/force signal to that of sensed so as to damp out the vibrations. The designed algorithm is implemented on Lab VIEW 2010 on Windows 7 Platform.Defence Science Journal, 2013, 63(4), pp.413-417, DOI:http://dx.doi.org/10.14429/dsj.63.486

The Comparative Study of Vibration Control of Flexible Structure Using Smart Materials

Considerable attention has been devoted to active vibration control using intelligent materials as PZT actuators. This paper presents results on active control schemes for vibration suppression of flexible steel cantilever beam with bonded piezoelectric actuators. The PZT patches are surface bonded near the fixed end of flexible steel cantilever beam. The dynamic model of the flexible steel cantilever beam is derived. Active vibration control methods: optimal PID control, strain rate feedback control (SRF), and positive position feedback control (PPF) are investigated and implemented using xPC Target real-time system. Experimental results demonstrate that the SRF and PPF controls have better performance in suppressing the vibration of cantilever steel beam than the optimal PID control

Active Controller of Cantilever Beam Excited by Impact Load

البحث الحالي تناول نظام السيطرة الفعالة للعتبة المسندة من طرف واحد بتأثير صدمة ناتجة من حمل خارجي. كانت نمذجة ومحاكاة تصميم السيطرة على النظام بواسطة برنامج MATLAB وذلك باستخدام تقنية العناصر المحددة. النظام الفعال المسيطر استخدم ماطور مربوط على النهاية المسندة للعتبة للسيطرة على الاستجابة الديناميكية ولإعطاء نتائج دقيقه بتأثير الأحمال الخارجية. الترددات الطبيعية للنظام و المستحصله من التحليل قورنت مع النتائج المستحصلة من برنامج Ansys وكذلك مع النتائج المستحصله بواسطة بحث آخر.بينت المقارنات توافق جيد مع نسبة خطأ لاتتجاوز 0.76 بالمائة. تم الحصول من نتائج هذه الدراسة على انه الاستجابة الديناميكية للعتبة المسندة من طرف واحد و المسيطر أظهرت تخميد أفضل للصدمة الناتجة من الحمل الخارجي, وكان النقصان لأعلى قيمه في هذه الاستجابة بما يقارب 80% مقارنتا مابين بوجود وعدم وجود السيطرة للاستجابة في حالة ألعتبه المصنوعة من الحديد و المصنوعة من الألمنيوم للأحمال المسلطة الخارجية. وجد لنوع المعدن تأثير كبير على اهتزاز ألعتبه.This work investigated the active control system of cantilever beam excited by impact external load. The control design of the system was modeled and simulated by MATLAB program for the cantilever beam using finite element technique. The controller active system used motor attached at fixed end of the beam to control the dynamic response and to give accurate results under external excitation. The natural frequencies of the system obtained were compared with Ansys software and other research results. The comparisons shown good agreement with maximum percentage difference was (0.76)%. It was obtained from the results that the dynamic response for controlled cantilever beam exhibited better observation of the impact load, and the reduction of the overshoot was 80% approximately comparing between control and uncontrolled response for steel and aluminum beam for applied impact load. It obtained that the type of material had large effect on the vibration of the beam

Active vibration control of flexible structures by optimally placed sensors and actuators

PhD ThesisThe active vibration reduction of plane and stiffened plates was investigated using a genetic algorithm based on finite element modelling to optimise the location of sensors and actuators. The main aspects of this work were: Development of a finite element model for a plate stiffened by beams with discrete sensors and actuators bonded to its surface. Development of a finite element program for steel plates with various symmetrical and asymmetrical stiffening and edge conditions. Development of a genetic algorithm program based on the finite element modelling for the optimisation of the location and number of sensor/actuator pairs and feedback gain. Determination of optimum locations and feedback gain for collocated piezoelectric sensors and actuators on steel plates with various symmetrical and asymmetrical stiffening and edge conditions. Development of fitness and objective functions to locate sensors and actuators. Development of fitness and objective functions to determine the optimal number of sensors and actuators. Development of a reduced search space technique for symmetrical problems. Optimisation of vibration reduction control scheme parameters using the genetic algorithm. Optimisation of the number and location of sensor/actuator pairs and feedback gain to reduce material costs and structural weight and to achieve effective vibration reduction. The modelling was validated by comparison with conventional finite element analysis using ANSYS, and by experiment. The modelling was developed using a quadrilateral isoparametric finite element, based on first order shear deformation theory and Hamilton’s principle, which may be arbitrarily stiffened by beams on its edges. The model can be applied to flat plates with or without stiffening, with discrete piezoelectric sensors and actuators bonded to its surfaces. The finite element modelling was tested for flat and stiffened plates with different boundary conditions and geometries, and the results of the first six natural frequencies were validated with the ANSYS package and experimentally. A genetic algorithm placement strategy is proposed to find the global optimal distribution of two, four, six and ten sensor/actuator pairs and feedback gain based on the minimisation of optimal linear quadratic index as an objective function, and applied to a cantilever plate to attenuate the first six modes of vibration. The configuration of this global optimum was found to be symmetrically distributed about the dynamic axes of symmetry and gave higher vibration attenuation than previously published results with an asymmetrical distribution which was claimed to be optimal. Another genetic algorithm placement strategy is proposed to optimise sensor/actuator locations using new fitness and objective functions based on . This is applied to the same cantilever plate, and was also found to give a symmetrical optimal sensor/actuator configuration. As before, it was found that the optimal transducer locations are distributed with the same axes of symmetry and in agreement with the ANSYS results. A program to simulate the active vibration reduction of stiffened plates with piezoelectric sensors and actuators was written in the ANSYS Parametric Design Language (APDL). This makes use of the finite element capability of ANSYS and incorporates an estimator based on optimal linear quadratic and proportional differential control schemes to investigate the open and closed loop time responses. The complexity of the genetic algorithm problem is represented by the number of finite elements, sensor/actuator pairs and modes required to be suppressed giving a very large search space. In this study, this problem was reduced by the development of a new half and quarter chromosomes technique exploiting the symmetries of the structure. This greatly reduces the number of generations, and hence the computing time, required for the genetic algorithm to converge on the global optimal solution. This could be significant when the technique is applied to large and complex structures. Finally, new fitness and objective functions were proposed to optimise the number of sensor/actuator pairs required for effective active vibration reduction in order to reduce the added cost and weight. The number, location and feedback gain were optimised for the same cantilever plate and it was found that two sensor/actuator pairs in optimal locations could be made to give almost as much vibration reduction as ten pairs.Ministry of Higher Education and Scientific Research of Iraq

Active vibration control of smart composite plates using optimized self-tuning fuzzy logic controller with optimization of placement, sizing and orientation of PFRC actuators

This paper deals with optimization of the sizing, location and orientation of the piezo-fiber reinforced composite (PFRC) actuators and active vibration control of the smart composite plates using particle-swarm optimized self-tuning fuzzy logic controller. The optimization criteria for optimal sizing, location and orientation of the PFRC actuators is based on the Gramian controllability matrix and the optimization process is performed by involving the limitation of the plates masses increase. Optimal configurations of five PFRC actuators for active vibration control of the first six modes of cantilever symmetric ((90 degrees/0 degrees/90 degrees/0 degrees)s), antisymmetric cross-ply ((90 degrees/0 degrees/90 degrees/0 degrees/90 degrees/0 degrees/90 degrees/0 degrees)) and antisymmetric angle-ply ((45 degrees/-45 degrees/45 degrees/-45 degrees/45 degrees/-45 degrees/45 degrees/-45 degrees)) composite plates are found using the particle swarm optimization. The detailed analysis of influences of the PFRC layer orientation and position (top or bottom side of composite plates), as well as bending-extension coupling of antisymmetric laminates on controllabilities is also performed. The experimental study is performed in order to validate this behavior on controllabilities of antisymmetric laminates. The particle swarm-optimized self-tuning fuzzy logic controller (FLC) adapted for the multiple-input multiple-output (MIMO) control is implemented for active vibration suppression of the plates. The membership functions as well as output matrices are optimized using the particle swarm optimization. The Mamdani and the zero-order Takagi-Sugeno-Kang fuzzy inference methods are employed and their performances are examined and compared. In order to represent the efficiency of the proposed controller, results obtained using the proposed particle swarm optimized self-tuning FLC are compared with the corresponding results in the case of the linear quadratic regulator (LQR) optimal control strategy.This is the peer reviewed version of the article: Zorić, N.; Tomović, A.; Obradović, A.; Radulović, R.; Petrović, G. R. Active Vibration Control of Smart Composite Plates Using Optimized Self-Tuning Fuzzy Logic Controller with Optimization of Placement, Sizing and Orientation of PFRC Actuators. Journal of Sound and Vibration 2019, 456, 173–198. [https://doi.org/10.1016/j.jsv.2019.05.035

Active Vibration Suppression of Smart Structures Using Piezoelectric Shear Actuators

Active vibration damping using piezoelectric materials integrated with structural systems has found widespread use in engineering applications. Current vibration suppression systems usually consist of piezoelectric extension actuators bonded to the surface or embedded within the structure. The use of piezoelectric shear actuators/sensors has been proposed as an alternative, where the electric field is applied perpendicular to the direction of polarization to cause shear deformation of the material. We present an exact analysis and active vibration suppression of laminated composite plates and cylindrical shells with embedded piezoelectric shear actuators and sensors. Suitable displacement and electric potential fknctions are utilized to identically satisfy the boundary conditions at the simply supported edges. A solution to the resulting set of coupled ordinary differential equations is obtained by using either a power series or Frobenius series. The natural frequencies, mode shapes and through-thickness profiles of displacements, potential and stresses are presented for several lamination schemes. Active vibration suppression is implemented with positive position feedback (PPF) and velocity feedback. Frequency response curves with various controller frequencies, controller damping ratios and scalar gains demonstrate that an embedded shear actuator can be utilized to actively damp the fundamental mode of vibration. In addition, it is shown that suppression of the thickness modes is feasible using a piezoelectric shear actuator. An experimental and finite element investigation of the active vibration suppression of a sandwich cantilever beam using piezoelectric shear actuators is also performed. The beam is constructed with aluminum facings, foam core and two piezoelectric shear actuators. The finite element analyses are performed using the commercial finite element package ABAQUSIStandard 6.3- 1. It is shown experimentally for the first time that piezoelectric shear actuators can be utilized for active vibration suppression. There are significant reductions in beam tip acceleration amplitudes and settling time as a result of the positive position feedback and strain-rate feedback. The finite element shows good comparison with the experimental results

Optimal Placement of Collocated Sensors and Actuators in FRP Composites Substrate

In this thesis, Multi-Objective method is used for optimal placement of Collocated Sensors and Actuator, using integrated Genetic Algorithm. Optimal placement of piezoelectric sensors and actuators in a cantilever beam is found out by maximizing the controllability index and also observability index. First mode vibration is only considered for the present case. Finite element formulation for shell structure was used for the beam analysis by making the radius infinite, which results to the formulation for plate analysis. The cantilever beam was divided into twenty equal sections, where the piezoelectric material can be placed. In the present study four sensors and four actuators has been considered for collocated system. For non-collocated system four sensors was only considered. Results obtained from the work shows that the location for placement of piezoelectric material for non-collocated system is same as that obtained from multi-objective collocated system. Hence it can be deduced, it is not needed to find out the location for sensors and actuators separately rather controllability index for both can be found out together by using multi-objective collocated formulation