Evaluation of numerical inversion of Laplace transformed solutions

Author

Yu-Chwin Lin, New Jersey Institute of Technology

Document Type

Thesis

Date of Award

1-31-1987

Degree Name

Master of Science in Mechanical Engineering - (M.S.)

Department

Mechanical Engineering

First Advisor

Herman, Harry

Second Advisor

Bernard Koplik

Third Advisor

Avraham Harnoy

Abstract

Here, some linear physical systems are analyzed by using the standard Numerical Laplace Transformation and Inversion method, including undamped and damped systems:

1. Undamped system: A bar clamped at one end and at one end free.

2. Damped system: Viscously damped linear discrete system.

The advantage of the Numerical Laplace Transformation method is that it reduces the inversion of the Laplace transformed solution to numerical integration; it makes the problem much easier to solve. In the present work, we also studied a new Numerical Laplace Transformation Inversion method by Wilcox (App.0 and Ref.l). The merit of this new method is that it is able to meet specification for f_max and T_max with far fewer samples than are necessary with the standard method.

The results indicate that the Numerical Laplace Transformation and Inversion method can produce results of comparable accuracy only for one degree of freedom systems and two degree of freedom systems with step function input, both for undamped and damped systems. For two degree of freedom systems with harmonic function input, this method did not yield satisfactory results.

Recommended Citation

Lin, Yu-Chwin, "Evaluation of numerical inversion of Laplace transformed solutions" (1987). Theses. 3284.
https://digitalcommons.njit.edu/theses/3284