Significance Statement
Asymmetric and laminated composite structures have gained much popularity in automotive, civil, aerospace and structural engineering among other fields due to their low density, high temperature resistance and high stiffness and strength to weight ratio. Piezoelectric materials are equally popular due to their high material linearity, low power consumption and quick response when induced by external forces. Therefore, by integrating smart materials such as piezoelectric sensors and actuators with laminated composite structures, smart-intelligent composite systems have been developed. These devices have proven to be of superior characteristics to their convectional counterparts.
Smart cantilever composite beams and plates are vital structural elements, but their precise analytical evaluation is among the most complicated problems in the concept of elasticity. Smart laminated cantilever composite plates can be adopted widely in various engineering applications such as morphing airplane wings, corrugated plates, reinforced concrete slabs, decks of contemporary steel bridges, boom arms of industrial cranes, and flight control surfaces. Until now, there was no exact analytical solutions for the twisting analysis of smart laminated cantilever composite structures induced by electrical twisting moments. Usually, multiscale and approximate solutions are adapted for the analytical evaluation of the smart composite laminates even though they are intricate and necessitate characteristic and trial deflections functions to be determined.
In a recent paper published in Composite Structures, Dr. Soheil Gohari, Dr. Shokrollah Sharifi, and Associate Professor Zora Vrcelj at Victoria University in Australia developed a new method that involves a novel explicit solution for the twisting deformation analysis and control of smart laminated cantilever composite plates and beams using inclined piezoelectric actuators. They hoped to develop a new way of precisely analyzing the twisting deformation in smart laminated cantilever composite structures induced by electrical twisting moments.
First, mathematical modelling of a laminated cantilever composite plate, having orthotropic layers and a predetermined layup thickness, was developed. The researchers then adapted the linear piezoelectricity and plate theories for analysis of the twisting deformation. They then employed a novel double integral multi-variable Fourier transformation and discretized higher order partial differential unit step function equations.
From the above equations, the researchers were able to obtain an exact analytical solution that could be used to analyze electro-mechanical twisting moments in smart laminated composite structures. Apparently, the research team was faced with a problem since there was no published data to compare and validate the results with. This led to a simple, robust and accurate finite element analysis model and realistic electromechanical coupled finite element procedures to be developed so as to ensure an effective method to solve the structural behavior of smart laminated piezo-composite structures under arbitrary loads.
From this study, a new unambiguous exact analytical solution has been presented for determining the twisting and bending deformation and optimal shape control of smart laminated cantilever composite plates and beams by using inclined piezoelectric actuators. The new method discovered here is seen to be reliable while compared with the incumbent finite element procedures. The shape control of laminated composite structures, as noted here, can also be controlled by varying the applied voltage and inclination angle. The new proposed method does not call for characteristic and trial deflection functions to be determined. It shows an excellent agreement from comparison results, hence most suitable for the stated applications.
Reference
Soheil Gohari, S. Sharifi, Zora Vrcelj. A novel explicit solution for twisting control of smart laminated cantilever composite plates and beams using inclined piezoelectric actuators. Composite Structures volume 161 (2017) pages 477–504
College of Engineering and Science, Victoria University, Melbourne, VIC 8001, Australia.
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