Structural Engineering and Mechanics

Volume 16, Number 2, 2003, pages 153-176

DOI: 10.12989/sem.2003.16.2.153

The exact solutions for the natural frequencies and mode shapes of non-uniform beams carrying

Der-Wei Chen

Abstract

From the equation of motion of a \"bare\" non-uniform beam (without any concentrated elements), an eigenfunction in term of four unknown integration constants can be obtained. When the last eigenfunction is substituted into the three compatible equations, one force-equilibrium equation, one governing equation for each attaching point of the concentrated element, and the boundary equations for the two ends of the beam, a matrix equation of the form [B]{C} = {0} is obtained. The solution of (where

Key Words

non-uniform beam; natural frequencies; mode shapes; bare beam; constrained beam; eigenfunction.

Address

Department of Naval Architecture and Marine Engineering, Chung Cheng Institute of Technology, <br />National Defense University, Yuansulin, Dashi, Taoyuan, Taiwan 335, Republic of China