Near-elimination of small oscillations of articulated flexible-robot systems

Shabana, Ahmed A.; Eldeeb, Ahmed E.; Bai, Zhengfeng

doi:10.1016/j.jsv.2021.116015

Cited by 4 publications

(1 citation statement)

References 6 publications

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“…This important concept of the ANCF mesh topology can be better explained using the articulated-robot system shown in Figure 2. 159 The links, which are connected by pin joints cannot be translated relative to each other and cannot have relative rotations about axes perpendicular to the joint axes regardless of the load applied. The pin joint does not transmit moment, and one link is free to rotate with respect to the other without resistance if the joint does not have compliance or friction.…”

Section: Ancf Mesh Topologymentioning

confidence: 99%

Mechanically induced temperature oscillations in the coupled thermo-elasticity analysis of articulated dynamical systems

Shabana

2023

Proceedings of the Institution of Mechanical Engineers, Part K:

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This article discusses a new approach for predicting and quantifying mechanically induced temperature oscillations in the coupled thermo-elasticity analysis of articulated mechanical systems (AMS). In this approach, the constrained equations of motion are solved simultaneously with discrete temperature equations obtained by converting heat partial-differential equation to a set of first-order ordinary differential equations. Dependence of the temperature gradients and their spatial derivatives on the position gradients, spinning motion, and curvatures is discussed. The approach captures dependence of the temperature-oscillation frequencies on the mechanical-displacement frequencies. The temperature field can be selected to ensure continuity of the temperature gradients at the nodal points. To generalize the AMS coupled thermo-elasticity formulation and capture the effect of the boundary and motion constraints (BMC) on the thermal expansion, the proposed method is based on integrating thermodynamics and Lagrange-D’Alembert principles. The absolute nodal coordinate formulation (ANCF) is used to describe continuum displacement and obtain accurate description of the reference-configuration geometry and change of this geometry due to deformations. A thermal-analysis large-displacement formulation is used to allow converting heat energy to kinetic energy, ensuring stress-free thermal expansion in case of unconstrained uniform thermal expansion. Cholesky heat coordinates are used to define an identity coefficient matrix for the efficient solution of the discretized heat equations. The approach presented is applicable to the two different forms of the heat equation used in the literature; one form is explicit function of the stresses while the other form does not depend explicitly on the stresses. Because of the need for using ANCF finite elements to achieve a higher degree of continuity in the coupled thermomechanical approach introduced in this article, the concept of the ANCF mesh topology is discussed.

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Section: Ancf Mesh Topologymentioning

confidence: 99%