[Download] "Continuous Systems" by Wayne Tustin, Deepak Jariwala & Jaime Boscá * eBook PDF Kindle ePub Free
eBook details
- Title: Continuous Systems
- Author : Wayne Tustin, Deepak Jariwala & Jaime Boscá
- Release Date : January 31, 2013
- Genre: Engineering,Books,Professional & Technical,Education,
- Pages : * pages
- Size : 72705 KB
Description
Now you are ready to move beyond the Single Degree-of-Freedom (SDoF) system of ebooks 2 to 9, the simplest possible system, having one spring, one “solid body” mass and one damper. SDoF adequately represents some real but truly simple systems such as the “workings” of accelerometers, electrodynamic (ED) shakers, etc.
Most vibration courses, at this point, move to Multi Degree-of-Freedom systems (MDoF), having two or more springs, masses and dampers, and adequately representing relatively simple systems with a few natural frequencies.
Let us skip over MDoF systems and instead move to truly complex systems, which better represent “real world” mechanical systems. Now you will learn that the properties of mass, springiness and damping are distributed, rather than concentrated, behaving more like the electrical engineer’s antennas, waveguides, etc., rather than behaving like the obvious “lumped constant” capacitors, inductors and resistors sometimes used.
Perhaps an example cantilever will aid our discussion. Obtain a metallic bar or scrap of sheet metal, perhaps 1/16” or 1.5 mm thick, 1/2” or 10 mm wide and 6” or 150 mm long. Examine it. You still have the properties of mass, springiness and damping or friction, but now they are distributed, rather than concentrated.
Convert that beam into a cantilever. Clamp one end to a table and pluck the free end. Observe that the cantilever beam has at least one natural frequency, at which it “likes” to vibrate. The beam moves through a succession of positions much like the positions shown in Animation 10.1.1. If you had a “strobe” light flashing at nearly the same frequency as your beam vibrates, it would appear to slow the action, as in the animation. You are exciting the first (of several) bending modes.
10.1 The Continuous System Model
10.2 Calculating first bending fn
10.3 Effect of damping
10.4 Identifying natural frequencies
10.5 Superposition
10.6 Beams and plates
10.7 Printed wiring cards
10.8 Plate damping
10.9 Force measurements
10.10 Units of force
10.11 Dynamic ratios
10.12 More damping applications
10.13 Phase changes
10.14 Active shape control
10.15 Fatigue failures
10.16 Axial resonances