Development and three-dimensional modeling of a bionic robotic fish with pectoral fins

Ocean Engineering, Journal Year: 2025, Volume and Issue: 321, P. 120393 - 120393

Published: Jan. 27, 2025

Language: Английский

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Parameter Optimization and Experimental Study on Alfalfa Stem Flattening Process Based on DEM–MBD

Agriculture, Journal Year: 2025, Volume and Issue: 15(9), P. 922 - 922

Published: April 23, 2025

To address issues such as uneven flattening and high stem breakage rate in post-harvest alfalfa field conditioning operations, an adjustable-clearance modulating device was designed. The incorporates a dual-spring floating pressure mechanism preload adjustment to ensure the adaptive performance of rollers during flattening. Based on biological characteristics stems, rigid–flexible coupling model between stems established. Using Discrete Element Method (DEM) Multibody Dynamics (MBD) co-simulation technology, experiments were conducted with feeding amount, roller speed, buffer spring force test factors, while crushing bonding key fracture served evaluation indices. Box–Behnken experimental design employed simulate dynamic process, followed by regression analysis simulation results. findings revealed optimal parameter combinations follows: amount 5.10 kg/s, modulation speed 686.87 r/min, 670.02 N. According combination parameters carry out tests, average 95.71% 1.73%, respectively, which showed small relative error predicted value met requirements steam operation. These research provide theoretical basis technical support for optimization devices.

Language: Английский

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Fluid–Structure Interaction Analysis of Manta-Bots with Self-Induced Vertical Undulations during Fin-Based Locomotion

Journal of Marine Science and Engineering, Journal Year: 2024, Volume and Issue: 12(7), P. 1165 - 1165

Published: July 10, 2024

Driven by the demands of ocean exploration, an increasing number manta ray-inspired robots have been designed and manufactured, primarily utilizing flexible skeletons combined with motor-driven mechanisms. However, mechanical analysis these designs remains underdeveloped, often relying on simplistic imitation biological prototypes typically neglecting vertical motion induced pectoral fin flapping. This paper presents a fluid–structure interaction framework that couples rigid body elastic deformation using multibody dynamics vortex particle method. An implicit iterative algorithm Aitken relaxation is employed to address added-mass instability, has validated against experimental data. representative manta-bot model shows self-induced undulations reduce thrust coefficient approximately 40% compared fixed degrees freedom, while slightly improving overall propulsive efficiency. The study also highlights critical role mass distribution in manta-bots, noting excessive focus complex movements large can significantly displacement, ultimately proving counterproductive.

Language: Английский

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Optimal design of a hybrid compliant mechanism considering the dynamic behavior of membrane-loaded

Nonlinear Dynamics, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 4, 2024

Language: Английский

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Modelling and analysis of nonlinear dynamics of rigid-flexible coupled structures

Journal of Physics Conference Series, Journal Year: 2024, Volume and Issue: 2891(13), P. 132010 - 132010

Published: Dec. 1, 2024

Abstract In the rigid-flexible coupled structure, coupling between elastic deformation motion of flexible structure and wide range rigid body will make dynamic behaviour more complicated. This paper established a class structures with attachments as body-cantilever beam model. The nonlinear equations are by taking stiffening into consideration. responses obtained numerical simulations. results show that transverse vibration frequency increases increase angular velocity body. Moreover, there be significant difference two linear dynamics model (LM) (NM) in certain situations due to effect stiffness term.

Language: Английский

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