Session: 07-02-01: Nonlinear Dynamics, Control, and Stochastic Mechanics

Paper Number: 113209

113209 - Nonlinear Dynamics Simulation of R-RTR Planar Mechanism 

The planar R-RTR mechanism with two moving links and guide is considered at different speeds. The R-RTR mechanism is consisted from driver link, slider, ground, and rocker link.  The proposed mechanism is used to actuate a hinged joint in construction equipment such as crane and backhoe. Moreover the application of this work is to open and close a swinging gate or door. The planar links with the dimensions (100, 50, and 150 mm) are selected for the driver link, ground, and rocker link respectively while the motor speeds such as (100 rpm, 300 rpm, 500 rpm, 700 rpm, and 900 rpm) are assigned to the driver link.  The algorithm code of dynamic tool is used to calculate global and correlation dimensions. Global dimensions is an algorithm which determines the global number of coordinates in a space domain of linear displacement while the method of false nearest neighbors is used. The general dimensions is projected on the x-axis in which it is necessary for unfolding the data of the motor torque against time. The correlation dimension is a measure of the fractal character of the strange attractor. The external moment is applied on the rocker link which is a function of angular velocity. The level of chaos is investigated using correlation dimension based on the value of time delay at different speeds for the driver link. Time delay is calculated using the algorithm of average mutual information of the dynamic tool. The motor torque is simulated at different speeds for the driver link in the presence of the inertia torque expression using SolidWorks program. Time delay, decorrelation time, and ‘bad’ predict time are used in the calculation of correlation dimension value with the aid of MatLab code. On the other hand, the level of chaos is detected using Fast Fourier Transform using power spectrum and autocorrelation analyses. The motor torque of the driver link against time is used in the calculation of time delay, correlation dimension, and Fast Fourier Transform (FFT). The value of the correlation dimensions are decreased with the increasing of number of samples of the motor torque until all the trends of correlation dimensions settled down. The overshoot peak of the motor torque has the same values at all speeds of the driver link. The dwell period of time between the two cycles of the motor torque is decreased with the increasing of the speeds of the driver link.

Presenting Author: Louay Alroomi San Diego State University

Presenting Author Biography: Dr. Louay S. Yousuf is a Visiting Assistant Professor at San Diego State University for one academic year in the Department of Mechanical Engineering. He received his Ph.D. from the University of Baghdad, Baghdad, Iraq and was a Postdoctoral Fellow at the Mechanical Engineering Department, University of Auburn, Alabama before joining San Diego State University. His research interests include non-linear dynamics of cam and follower, composite materials, finite element method, vibrations, and experimental stress analysis.

Contact Information: lalroomi@sdsu.edu; Phone: (334) 332-5771.

Authors:

Louay S. Yousuf San Diego State University