Mechanic of Advanced and Smart Materials
Quarterly

Dynamic Simulation of a Soft Fluidic Actuator with Finite Element Method

Document Type : Original Article

Authors

Melika Mohammadi 1
Ahmad Karimi 2
Mahdi Bamdad 3
Seyyed Ali Sina 2

1 Department of Mechanical Engineering, Faculty of Engineering, Ferdowsi University of Mashhad

2 Mechanical Engineering Department, Shahrood University of Technology, Shahrood, Iran

3 School of Computer Science and Engineering, University of New South Wales, Sydney, Australia

https://doi.org/10.66224/masm.5.3.437
Abstract
This paper presents a comprehensive vibrational and static analysis of a soft actuator considering nonlinear effects. Fluidic channels embedded within a soft beam are considered a soft robotic actuator, exhibiting nonlinear characteristics due to the inherent properties of the soft material. The analytical process is based on Hamilton's principle, and the numerical solution has been carried out using the finite element software ANSYS, utilizing the Fluid-Structure Interaction (FSI) and Pre-stress Modal tools. Initially, time-dependent inlet pressure is applied, and the resulting pressure distribution within the soft fluidic actuator (SFA) is extracted over the time domain. Following the validation of results obtained from finite element software and analytical methods, the feasibility of using this actuator as an artificial muscle in a robotic fish has been examined, leveraging the phenomenon of resonance and analyzing its behavior under real-world conditions. The findings indicate that utilizing this type of actuator in the robotic fish's tail enables functional similarity to a real fish after 8 seconds. However, by applying the proposed method and tuning the operating frequency closer to the system’s natural frequency, the robot can immediately exhibit movements resembling those of a biological fish.

Keywords

Soft Fluidic Actuator
Fluid-Structure Interaction
Bio-inspired Robot Fish
Modal Analysis
Resonance Tuning
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Mechanic of Advanced and Smart Materials
Volume 5, Issue 3
Autumn 2025
Pages 437-462

  • Receive Date 16 June 2026
  • Revise Date 14 July 2026
  • Accept Date 18 July 2026

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