Introduction to Adams Vibration

Using Adams Vibration, you can compute system response in the frequency domain. You can perform two types of analyses:

A normal modes analysis computes eigenvalues and eigenvectors of your model at any operating point you specify. We define an operating point as the current configuration of the model. You may launch either a normal modes analysis or a forced response analysis at any type of operating points, static or dynamic. These analyses are effective in understanding natural modes of vibration for the model and in determining the basic dynamic characteristics of your model.

Normal modes analysis is relevant in many scenarios. In one scenario, you may need to assess dynamic interaction between parts in an Adams model. For example, if you are designing a washing machine, it is necessary to determine if the operating rotational frequency of the tub is close to one or more natural frequencies of the supporting structure and electronic components. If they are, then ordinary operation of the washing machine may lead to damage of the supporting structure and/or premature failure of electrical and electronic components in the machine.

If you are setting up a physical test, a normal-modes analysis is useful in determining the best location on your systems to attach strain gauges and/or accelerometers. After the test, test results can be correlated with the results of the normal-modes analysis.

Frequency-response analysis is an efficient method for finding the steady-state model response to sinusoidal excitation. In this analysis, the loading is in the form of a sine wave for which you specify the frequency, amplitude, and phase. Adams Vibration performs frequency response analysis using linearized Adams models. Several different types of inputs can be applied to the model and force and kinematic output measured.

This document describes the theory and modeling constructs used in Adams Vibration. It is a companion to the on-line product documentation. We assume you are familiar with using the product in its interactive or batch environments. If not, consult the on-line product documentation for Adams Vibration before reading this document.

The next section presents linearization theory for Adams model followed by definitions of vibration modeling entities available in Adams Vibration. Next, we discuss acoustic pressure recovery, and finally the last section provides a list of references you may want to consult for more details on the respective topics.