How fish body stiffness distribution affects swimming performance: a theoretical perspective.

Area of Science:

• Biomechanics
• Robotics
• Hydrodynamics

Background:

• Fish swimming locomotion is significantly influenced by body stiffness.
• Biological studies reveal heterogeneous stiffness across fish body segments.
• Stiffness generally decreases from anterior to posterior in fish.

Purpose of the Study:

• To develop an analytical model integrating fish body stiffness distribution into locomotion analysis.
• To investigate the effects of various stiffness distribution patterns on swimming performance.
• To provide foundational insights for designing variable-stiffness robotic fish.

Main Methods:

• Discretization of the resistive drag model.
• Incorporation of active bending moment distribution functions.
• Development of an analytical model for fish locomotion incorporating stiffness distribution.

Main Results:

• A rapidly decreasing stiffness distribution enhances swimming performance.
• A low ratio of minimum-to-maximum stiffness is optimal for locomotion.
• Investigated effects of different segment quantities and decreasing distribution patterns.

Conclusions:

• Stiffness distribution is a critical factor in efficient fish swimming.
• The developed model supplements biological experiments and informs robotic fish design.
• Optimal stiffness patterns can guide the development of advanced robotic swimmers.