Modeling viscoelastic behavior in flexible multibody systems
- PDF / 1,792,598 Bytes
- 36 Pages / 439.37 x 666.142 pts Page_size
- 43 Downloads / 262 Views
Modeling viscoelastic behavior in flexible multibody systems Olivier A. Bauchau1
· Nishant Nemani1
Received: 29 May 2020 / Accepted: 8 November 2020 © Springer Nature B.V. 2020
Abstract Viscoelasticity plays an important role in the dynamic response of flexible multibody systems. First, single degree-of-freedom joints, such as revolute and prismatic joints, are often equipped with elastomeric components that require complex models to capture their nonlinear behavior under the expected large relative motions found at these joints. Second, flexible joints, often called force or bushing elements, present similar challenges and involve up to six degrees of freedom. Finally, flexible components such as beams, plates, and shells also exhibit viscoelastic behavior. This paper presents a number of viscoelastic models that are suitable for these three types of applications. For single degree-of-freedom joints, models that capture their nonlinear, frequency-dependent, and frequency-independent behavior are necessary. The generalized Maxwell model is a classical model of linear viscoelasticity that can be extended easily to flexible joints. This paper also shows how existing viscoelastic models can be applied to geometrically exact beams, based on a threedimensional representation of the quasi-static strain field in those structures. The paper presents a number of numerical examples for three types of applications. The shortcomings of the Kelvin–Voigt model, which is often used for flexible multibody systems, are underlined. Keywords Flexible multibody systems · Viscoelasticity · Motion formalism · Finite element analysis
1 Introduction Flexible multibody systems are characterized by two distinguishing features: system components undergo finite relative motion and these components are connected by mechanical joints that impose constraints on their relative motion. Most studies focus on modeling of the
B O.A. Bauchau
[email protected] N. Nemani [email protected]
1
Department of Aerospace Engineering, University of Maryland, College Park, MA, 200742, USA
O.A. Bauchau, N. Nemani
dynamic response of the elastic components that undergo large motion and on the enforcement of the kinematic constraints at the joints. The analysis of the viscoelastic behavior of the structural components and that of the elastomeric devices often housed in the mechanical joints has received far less attention despite the fact that viscoelastic phenomena affect the dynamic response significantly. In the context of flexible multibody systems, the tools used to analyze viscoelastic components fall into three categories, depending on the number of degrees of freedom used to describe their kinematics. In the first category, the kinematics of the problem is described by a single generalized coordinate. Two practical examples come to mind: a single degree of freedom, the relative rotation or displacement component, is used to describe the kinematics of elastomeric devices housed in revolute or prismatic joints, respectively. For revolute joints, t
Data Loading...
