Transient Dynamic Analysis of Rotors Using SMAC Techniques: Part 1, Formulation

1992 ◽  
Vol 114 (4) ◽  
pp. 477-481 ◽  
Author(s):  
S. Ratan ◽  
J. Rodriguez
Keyword(s):  
Dynamic Analysis ◽  
Equations Of Motion ◽  
The Finite Element Method ◽  
Time Step ◽  
Transient Dynamic Analysis ◽  
Transient Dynamic ◽  
Rotor Systems ◽  
Efficient Scheme ◽  
Time Marching ◽  
Equations Of Motions

A new method is introduced for performing transient dynamic analysis of rotor systems using a Successive Merging and Condensation (SMAC) technique. This approach can be applied to rotor analysis problems formulated with the finite element method. Condensation is done on the partitioned equations of motions for an element, and the result is merged into the next element’s equations of motion. Such manipulations result in a reduced size for the system’s matrices, producing a computationally more efficient scheme. After the boundary conditions are applied, a time-marching scheme provides the transient solution at each time step.

DYNAMIC SIMULATION OF A VEHICLE WITH SEMI-TRAILING A-ARM SUSPENSIONS

1996 ◽  
Vol 20 (2) ◽  
pp. 175-186
Author(s):  
Hazem Ali Attia
Keyword(s):  
Dynamic Analysis ◽  
Dynamic Simulation ◽  
Efficient Solution ◽  
Equations Of Motion ◽  
Equivalent System ◽  
Constraint Forces ◽  
Transient Dynamic Analysis ◽  
Transient Dynamic ◽  
Dynamic Formulation ◽  
System Of Particles

In this paper the transient dynamic analysis of a vehicle with semi-trailing A-arm suspensions is presented. The equations of motion are formulated using a two step transformation. Initially, the formulation is written in terms of a dynamically equivalent system of particles. The equations of motion are then transformed to the relative joint variables. For open chains, this process automatically eliminates all of the non-working constraint forces and leads to an efficient solution and integration of the equations of motion. The results of the simulation indicate the simplicity and generality of the dynamic formulation.

Automated Vehicle Dynamic Analysis With Flexible Components

1984 ◽  
Vol 106 (1) ◽  
pp. 126-132 ◽  
Author(s):  
S. S. Kim ◽  
A. A. Shabana ◽  
E. J. Haug
Keyword(s):  
Dynamic Analysis ◽  
Equations Of Motion ◽  
Coupled System ◽  
Ride Quality ◽  
Vertical Acceleration ◽  
Transient Dynamic Analysis ◽  
Transient Dynamic ◽  
Generalized Coordinates ◽  
Rigid Body Model ◽  
Nonlinear Transient

A method is presented for nonlinear, transient dynamic analysis of vehicle systems that are composed of interconnected rigid and flexible bodies. The finite element method is used to characterize deformation of each elastic body and a component mode technique is employed to reduce the number of elastic generalized coordinates. Equations of motion and constraints of the coupled system are formulated in terms of a minimal set of modal and reference generalized coordinates. A Lagrange multiplier technique is used to account for kinematic constraints between bodies and a generalized coordinate partitioning technique is employed to eliminate dependent coordinates. The method is applied to a planar truck model with a flexible chassis and nonlinear suspension components. Simulation results for transient dynamic response as the vehicle traverses a bump, including the effect of bump-stops, and random terrain show that flexibility of the chassis can be routinely accounted for and predicts significant effects on vibratory motion of the vehicle. Compared with a rigid body model, flexibility of the chassis increases peak acceleration of the chassis and induces high-frequency vertical acceleration in the range of human resonance, measured in this paper as driver absorbed power, which deteriorates ride quality of off-road vehicles.

A Successive Merging and Condensation (SMAC) Method Applied to Transient Analysis of Multi-Shaft Rotor System

1993 ◽  
Author(s):  
Santosh Ratan ◽  
Jorge Rodriguez
Keyword(s):  
Transient Response ◽  
Transient Analysis ◽  
Rotor System ◽  
Time Step ◽  
Transient Dynamic Analysis ◽  
Numerical Examples ◽  
Linear Coupling ◽  
Rotor Systems ◽  
Coupling Constraints ◽  
Smac Method

Abstract A method for performing transient dynamic analysis of multi-shaft rotor system is proposed. The proposed methodology uses the reported Successive Merge and Condensation (SMAC) method [12] and a decoupling technique to decouple the shafts. Multi-shaft rotor systems are treated as systems of many independent single shaft rotor systems with external unknown coupling forces acting at the points of couplings. For each time step, first, the SMAC method is used to get the transient response in terms of the unknown coupling forces. This is followed by the application of the coupling constraints to calculate the coupling forces and, in turn, the response at the end of that time step. The proposed method preserves the efficiency advantages of the SMAC algorithm for single-shaft rotor system. Numerical examples to validate and illustrate the applicability of the method are given. The method is shown to be applicable to linear and non-linear coupling problems.

Sign in / Sign up

Export Citation Format

Share Document