TABLE OF CONTENTS The response process of a vibratory system may be that of a displacement, or of an acceleration, or of a stress, or of some other dynamic quantity. It would be highly desirable if the statistics on such dynamic response quantities would be converted simply into statistics on the reliability of the structure or equipment in the random vibration environment. This would then provide information directly useful to the designer or test engineer. Even though many failure mechanisms of structures are basically governed by the vibration environment, it should not be forgotten that other environmental factors such as temperature, pressure, load, radiation, etc. can often interact with the vibration environment to alter the nature of the failure mechanisms; e.g., the strength of a vibrating member can be sharply temperature dependent. Here, only random vibration caused failures are considered. Reliability quantification for the temperature-vibration combined environment will be discussed in the next section.
Let Y( t) be a dynamic response quantity in a vibratory system. At least three different failure mechanisms can be envisioned:
Failure can occur the first time that Y( t) reaches a certain fixed level Y F. For example, Y( t) might be the relative displacement necessary to cause a short circuit; or Y( t) might be the relative displacement of a resiliently supported package which fails when the resilient support bottoms out after traveling through the...
