Ideal Compliant Joints and Integration of Computer Aided Design and Analysis

Abstract

This paper discusses fundamental issues related to the integration of computer aided design and analysis (I-CAD-A) by introducing a new class of ideal compliant joints that account for the distributed inertia and elasticity. The absolute nodal coordinate formulation (ANCF) degrees of freedom are used in order to capture modes of deformation that cannot be captured using existing formulations. The ideal compliant joints developed can be formulated, for the most part, using linear algebraic equations, allowing for the elimination of the dependent variables at a preprocessing stage, thereby significantly reducing the problem dimension and array storage needed. Furthermore, the constraint equations are automatically satisfied at the position, velocity, and acceleration levels. When using the proposed approach to model large scale chain systems, differences in computational efficiency between the augmented formulation and the recursive methods are eliminated, and the CPU times resulting from the use of the two formulations become similar regardless of the complexity of the system. The elimination of the joint constraint equations and the associated dependent variables also contribute to the solution of a fundamental singularity problem encountered in the analysis of closed loop chains and mechanisms by eliminating the need to repeatedly change the chain or mechanism independent coordinates. It is shown that the concept of the knot multiplicity used in computational geometry methods, such as B-spline and NURBS (Non-Uniform Rational B-Spline), to control the degree of continuity at the breakpoints is not suited for the formulation of many ideal compliant joints. As explained in this paper, this issue is closely related to the inability of Bspline and NURBS to model structural discontinuities.

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Document Details

Document Type
Technical Report
Publication Date
Nov 17, 2013
Accession Number
ADA590062

Entities

People

  • Ahmed A. Shabana
  • Antonio M. Recuero
  • Ashraf M. Hamed
  • David J. Gorsich
  • Michael D. Letherwood
  • Paramsothy Jayakumar

Organizations

  • University of Illinois at Chicago

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Complex Systems
  • Computational Science
  • Computer Simulations
  • Computer-Aided Design
  • Computers
  • Continuity
  • Coordinate Systems
  • Discontinuities
  • Elastic Properties
  • Equations
  • Finite Element Analysis
  • Geometry
  • Linear Algebraic Equations
  • Mechanics
  • Modulus Of Elasticity
  • Tracked Vehicles
  • Vehicles

Readers

  • Approximation Theory.
  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)