Fazl e Ahad

Inverse Kinematic Analysis of Three Link Mechanism for Fin Actuation of Fish Like Micro Device

In this paper, inverse kinematic analysis of a proposed three link mechanism of a bio-inspired micro scanning device towed underwater by a surface vessel to actuate its aileron fins for its depth control and for its stabilization against roll is performed. Mechanism is actuated by IPMC actuators. To speed up the design verification process, computer aided simulations are used to perform motion analysis of the proposed IPMC actuated mechanism through Pro/Mechanism tool. Inverse kinematic analysis is performed to find out the joint variables of the mechanism to realize fin actuation along desired path. Displacements, velocities and accelerations of the links constructing mechanism are found out to establish their interrelationship. Results are analysed for the study of mechanism efficacy and for sizing the IPMC actuators. This paper contributes to introduce a new approach of virtual prototyping using advanced simulation tools for analysis and design verification of IPMC actuated mechanisms for biomimetic applications before moving into functional prototype stage.

Dynamic Analysis of IPMC Actuated Fin of a Micro Fish Like Device

In this paper, a methodology is presented to perform dynamic analysis of structural linked mechanisms under true actuation cycle and force response of applied IPMC actuators. Dynamic analysis of a three link mechanism for fin actuation of a micro fish like device, towed by a surface vessel through tow cable, is performed through this methodology and same is applicable to other biomimetic robotic applications. Fluid (water) exerts a torque on IPMC actuated fin which is a function of fins deflection and fluid flow velocity. Dynamic analysis is performed to assess the performance and efficacy of fin actuation mechanism under different loading conditions in terms of fins deflection, velocity and acceleration. Actuation force is increased by increasing number of applied IPMC actuators of known actuation cycle and force generation response. Applied torque is determined by performing a numerical simulation of IPMC actuated fin against different flow velocities through two-way fluid structure interaction (FSI) approach. Numerical simulation is performed in ANSYS WORKBENCH to capture the complex hydrodynamic interactions between fin and fluid. Effect of increased actuation force against constant flow velocity (towing speed) and of increased flow velocity against constant actuation force are evaluated in terms of fins deflection, velocity and acceleration. Finally, consequence of increasing the length of the link, connecting IPMC actuators and fin, are appraised for same actuation force and applied torque. Dynamic analysis is performed in Pro/ Mechanism, an advanced simulation tool. A technique of virtual prototyping through simulations is applied to access the performance of the fin actuation mechanism under true loading scenario before going into experimental phase, saving cost and time

Analytical Approaches to Vibration Analysis of Thick Plates Subjected to Different Supports, Loadings and Boundary Conditions - A Literature Survey

Plates are one of the most important structural components used in many industries like aerospace, marine and various other engineering fields and thus motivate designers and engineers to study the vibrational characteristics of these structures. A lot of research work and studies have been done to study its vibration characteristics. This paper is a review of existing literature on vibration analysis of plates. Focus has been kept on prominent studies related to isotropic plates based on Mindlin plate theory; however few citations on orthotropic plates and higher order shear deformation theories have also been included. All citations are in English language. This review is aimed to provide contemporarily relevant survey of papers on vibrational characteristics of thick plates and identification of various methods and approaches that have been used to study the vibration characteristics. This paper will not only be useful for scientists, designers and researchers to locate important and relevant literature/research quickly but will also help them to identify and apply some of these methods and approaches to study the vibration characteristics of various other 2D and 3D structures.