The Application of Finite Element Methods to the Dynamic Analysis of Flexible Spatial and Co-Planar Linkage Systems

1981 ◽  
Vol 103 (3) ◽  
pp. 643-651 ◽  
Author(s):  
W. Sunada ◽  
S. Dubowsky
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
High Speed ◽  
Robotic Manipulators ◽  
Component Mode Synthesis ◽  
System Of Equations ◽  
Flexible Links ◽  
Analysis Techniques ◽  
Spatial Mechanisms ◽  
Coordinate Reduction

An analytical method is presented for the dynamics of spatial mechanisms containing complex-shaped, flexible links with application to both high-speed industrial machines and robotic manipulators. Existing NASTRAN-type finite element structural analysis programs are combined with 4 × 4 matrix dynamic analysis techniques and Component Mode Synthesis coordinate reduction to yield a procedure capable of analyzing complex, non-linear spatial mechanisms with irregularly shaped links in great detail, yet producing a system of equations small enough for efficient numerical integration. The method is applied to two examples.

Selection of Degrees of Freedom for Dynamic Analysis

1987 ◽  
Vol 109 (1) ◽  
pp. 65-69 ◽  
Author(s):  
K. W. Matta
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
Degrees Of Freedom ◽  
General Purpose ◽  
Component Mode Synthesis ◽  
Complex Structures ◽  
Large Complex ◽  
Static Condensation ◽  
Basis Vectors ◽  
Selection Of

A technique for the selection of dynamic degrees of freedom (DDOF) of large, complex structures for dynamic analysis is described and the formulation of Ritz basis vectors for static condensation and component mode synthesis is presented. Generally, the selection of DDOF is left to the judgment of engineers. For large, complex structures, however, a danger of poor or improper selection of DDOF exists. An improper selection may result in singularity of the eigenvalue problem, or in missing some of the lower frequencies. This technique can be used to select the DDOF to reduce the size of large eigenproblems and to select the DDOF to eliminate the singularities of the assembled eigenproblem of component mode synthesis. The execution of this technique is discussed in this paper. Examples are given for using this technique in conjunction with a general purpose finite element computer program GENSAM[1].

Dynamic Analysis of a High-Speed Grinding Spindle

2011 ◽  
Vol 215 ◽  
pp. 89-94 ◽  
Author(s):  
Jing Zhu Pang ◽  
Bei Zhi Li ◽  
Jian Guo Yang ◽  
Zhou Ping Wu
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
High Speed ◽  
Grinding Wheel ◽  
Static Characteristics ◽  
Motorized Spindle ◽  
Element Analysis ◽  
Spindle System ◽  
The Finite Element Analysis ◽  
High Speed Grinding

This paper presents the effects of spindle system configuration on the dynamic and static characteristics of high speed grinding. A 3D physical mode of high-speed grinding motorized spindle system with rotation speed of 150m/s was provided. The motorized spindle system consists of bearings, rotor, stator, spindle housing and grinding wheel. Based on the finite element method (FEM), the static characteristics, dynamic and the transient response are analyzed based on the finite element analysis software NASTRAN. It is shown that the spindle overhanging, bearing span have a significant effort on spindle deflection. The dynamic analysis shows no resonance will happen during its speed range. The methods and solutions for the motorized spindle system design and engineering applications was given in this paper.

Dynamics of Robotic Manipulators With Flexible Links

1991 ◽  
Vol 113 (1) ◽  
pp. 54-59 ◽  
Author(s):  
Liang-Wey Chang ◽  
J. F. Hamilton
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Dynamic Model ◽  
Nonlinear Equations ◽  
Robotic Manipulators ◽  
The Finite Element Method ◽  
Small Motion ◽  
Flexible Links ◽  
Generalized Coordinates ◽  
Large Motion

This paper presents a dynamic model for the robotic manipulators with flexible links by means of the Finite Element Method and Lagrange’s formulation. By the concept of the Equivalent Rigid Link System (ERLS), the generalized coordinates are selected to represent the total motion as a large motion and a small motion. Two sets of coupled nonlinear equations are obtained where the equations representing small motions are linear with respect to the small motion variables. An example is presented to illustrate the importance of the flexibility effects.

Component Mode Synthesis Order-Reduction for Dynamic Analysis of Structure Modeled With NURBS Finite Element

2016 ◽  
Vol 138 (2) ◽  
Author(s):  
K. Zhou ◽  
G. Liang ◽  
J. Tang
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
Large Scale ◽  
Order Reduction ◽  
Reduction Technique ◽  
Component Mode Synthesis ◽  
Original Structure ◽  
Surface Geometry ◽  
Compatibility Conditions ◽  
B Splines

Nonuniform rational B-splines (NURBS) finite element has advantages in analyzing the structure with curved surface geometry. In this research, we develop a component mode synthesis (CMS) based order-reduction technique which can be applied to large-scale NURBS finite element dynamic analysis. In particular, we establish a new substructure division scheme. The underlying idea is to optimally construct interface between adjacent substructures that can maximize the geometry consistency between the original structure and the divided substructures and at the meantime facilitate the compatibility conditions needed in mode synthesis. Case studies are carried out to validate the performance of the order-reduction formulation.

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