Introduction to Adams/Vibration

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

1.	Normal-modes analysis

2.	Forced response analysis

A normal modes analysis computes eigen-values and eigenvectors of your model at an operating point you specify. This analysis is effective in understanding natural modes of vibration for the model and to determine the basic dynamic characteristics of your model. Although the result of an eigenvalue analysis is independent of specific excitation, they are useful in predicting the effects of applying dynamic loads on your model.

Normal modes analysis is relevant in many scenarios. In one scenario you may need to assess dynamic interaction between parts in an MD 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 MD 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 to be used as a companion to the on-line product documentation. It is assumed that 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 MD Adams model. This is followed by definition of vibration modeling entities available in Adams/Vibration. Solutions types available in Adams/Vibration are described in Section 4. The last section, Section 5, gives a list of references you may want to consult for more details on the respective topics.