Partitioned formulation of contact‐impact problems with stabilized contact constraints and reciprocal mass matrices

2021 ◽  
Author(s):  
José A. González ◽  
Ján Kopačka ◽  
Radek Kolman ◽  
K. C. Park
Keyword(s):  
Mass Matrices ◽  
Contact Impact ◽  
Impact Problems

Modeling of Contact/Impact Problems in Gear Systems Dynamics

1999 ◽  
Author(s):  
Leszek Demkowicz ◽  
Andrzej Bajer
Keyword(s):  
Model Problem ◽  
Body Motion ◽  
Systems Dynamics ◽  
Elastic Rod ◽  
Element Discretization ◽  
Elastic Wheel ◽  
One Step ◽  
Contact Impact ◽  
Impact Problems ◽  
Impact Problem

Abstract A discretization scheme for contact/impact problems related to the modeling of gears is proposed. The problem is first discretized in time and then a variational formulation for the resulted one step problem is developed. A Finite Element discretization completes the discretization process. The scheme is reinterpretation of the general Simo-Laursen-Chavla algorithm in the contest of rigid body motion superimposed with small elastic deformation; it conserves precisely linear momentum and total energy, and approximately the angular momentum. The discretization method is illustrated with two numerical examples: the standard 1D impact problem for an elastic rod, and a 2D model problem of an elastic wheel bouncing within a constraining box.

Fracture in Taylor Rod Impact Test Specimens

2010 ◽  
Author(s):  
Sachin S. Gautam ◽  
Ravindra K. Saxena ◽  
P. M. Dixit
Keyword(s):  
Ductile Fracture ◽  
Damage Mechanics ◽  
Continuum Damage Mechanics ◽  
Outer Edge ◽  
Impact Surface ◽  
Mechanics Model ◽  
Contact Impact ◽  
Impact Problems ◽  
The Impact ◽  
Aisi1045 Steel

High velocity contact-impact problems are of great interest in industries related to aerospace, mechanical and civil engineering. Ductile fracture often occurs in such applications. Taylor rod impact tests are used as experimental and numerical tests for determining the mechanical behaviour of materials subjected to high strain rates. At sufficiently high velocities, a significant plastic deformation leading to fracture is observed. In this paper, ductile fracture in Taylor rod made of AISI1045 steel is simulated using a continuum damage mechanics model. Simulations are performed for the velocity of 250 and 300 m/s. It is observed that, at lower velocities, tensile cracks are observed at the outer edge of the impact surface. On the other hand, at higher velocities, the fracture is observed at the central axis (confined fracture) as well as at the outer edge leading to fragmentation. Both the results are consistent with the experimental results available in the literature.

An Efficient Method for a Category of Contact/Impact Problems in Multibody Systems: Tree Topologies

2005 ◽  
Author(s):  
Michael J. Sadowski ◽  
Kurt S. Anderson
Keyword(s):  
Rigid Body ◽  
Dynamic Systems ◽  
Equations Of Motion ◽  
Momentum Balance ◽  
Unilateral Constraints ◽  
Constraint Forces ◽  
Rigid Body Dynamic ◽  
Tree Topologies ◽  
Contact Impact ◽  
Impact Problems

This paper presents an algorithm for the efficient numerical analysis and simulation of a category of contact/impact problems in multi-rigid-body dynamic systems with tree topologies. The algorithm can accommodate the jumps in structure which occur in the equations of motion of general multi-rigid-body systems due to a contact/impact event between bodies, or due to the locking of joints as long as the resulting system is a tree topology. The presented method uses a generalized momentum balance approach to determine the velocity jumps which take place across impacts in such multibody dynamic systems where event constraint forces are of the “non-working” category. The presented method does not suffer from the performance (speed) penalty encountered by most other momentum balance methods given its O(n) overall cost, and exact direct embedded consideration of all the constraints. Due to these characteristics, the presented algorithm offers superior computing performance relative to other methods in situations involving both large n and potentially many unilateral constraints.

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