Thermo-elasticity displacement formulation for constrained articulated mechanical systems
Thermo-elasticity displacement formulation for constrained articulated mechanical systems
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DOI：
10.1080/15397734.2023.2191695
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发表时间：
2023-04
影响因子：
3.9
通讯作者：
A. Shabana;Mahmoud Elbakly;M. Abdalla;A. E. Eldeeb
中科院分区：
文献类型：
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作者：
A. Shabana;Mahmoud Elbakly;M. Abdalla;A. E. Eldeeb
摘要本文提出了一种考虑边界和运动约束的铰接系统热分析方法。该解决方案框架的目的是捕捉大的温度波动，由于参考配置和变形的几何形状的显着变化，以及由于铰接机械系统（AMS）的大位移和旋转运动的几何非线性。热膨胀位移，这并不有助于刚体平移，确定从热拉伸的位置梯度矢量使用一种新的扫描矩阵技术，旨在消除对平移刚体模式的依赖。定义了一种新的二次热能动力学形式，并用于制定考虑热瞬态和惯性效应的动态力矢量。节点的热位移被用于建立AMS微分/代数方程（DAE），从而，BMC方程引起的热应力被自动地基于热分析和Lagrange D 'Alembert原理的集成来计算，这是计算多体系统（MBS）算法的基础。在这项研究中所使用的大位移约束和无约束的热膨胀的方法是基于位置梯度矩阵的乘法分解，而不是应变加法分解，解决热弹性问题。四种配置用于定义连续体几何形状和位移：直线配置，参考配置，热膨胀配置，和当前配置。所提出的方法允许施加热载荷在受约束的大位移，不施加限制的热系数的选择，捕获参考配置的几何形状和惯性力的变化，由于温度波动，占热位移制定AMS非线性约束方程，并允许集成与MBS算法的研究范围广泛的热弹性问题。
Abstract This paper proposes an approach for thermal analysis of articulated systems subject to boundary and motion constraints (BMC). The solution framework is designed to capture large temperature fluctuations, significant change in geometry due to reference configuration and deformations, and geometric nonlinearity due to articulated mechanical systems (AMS) large displacements and spinning motion. Thermal-expansion displacements, which do not contribute to rigid-body translations, are determined from thermal stretch of position-gradient vectors using a new sweeping matrix technique designed to eliminate dependence on translational rigid-body modes. A new quadratic thermal-energy kinetic form is defined and used to formulate a dynamic force vector that accounts for thermal transient and inertia effects. Nodal thermal displacements are used in formulating AMS differential/algebraic equations (DAEs), and consequently, thermal stresses due to BMC equations are automatically accounted for based on integration of thermal analysis and Lagrange-D’Alembert principle, which is the foundation of computational multibody system (MBS) algorithms. The approach used in this study for large-displacement constrained and unconstrained thermal expansions is based on multiplicative decomposition of position-gradient matrix, instead of strain additive decomposition, for solution of thermo-elasticity problems. Four configurations are used to define continuum geometry and displacements: straight configuration, reference configuration, thermal-expansion configuration, and current configuration. The proposed approach allows applying thermal loads during constrained large displacements, does not impose restrictions on the choice of thermal coefficients, captures reference-configuration geometry and change in inertia forces due to temperature fluctuations, accounts for thermal displacement in formulating AMS nonlinear constraint equations, and allows for integration with MBS algorithms for the study of a wide range of thermo-elasticity problems.