ACCELERATED TESTS FOR RELIABILITY AND DURABILITY OF MACHINE BUILDING INDUSTRY PRODUCTS (USKORENNYE ISPYTANIYA NA NADEZHNOST I DOLGOVECHNOST IZDELII MASHINOSTROENIYA),
Abstract
Different methods for accelerated life and reliability testing are discussed qualitatively. Since it is not practical to wait 3 to 4 years to determine the reliability and wear characteristics of a given machine, accelerated tests must be performed which will give sufficient data in 3 to 6 weeks to predict the long-term behavior of machine elements. This can be achieved by either increasing the number of cycles per unit time, by intensifying the loads, or by both methods. It has been shown repeatedly that wear processes and fatigue processes can be extrapolated from limited test data with an accuracy of plus or minus 10%. Although under industrial conditions the scatter may be as much as plus or minus 150%, these extrapolation techniques give an excellent indication of average wear, life, and reliability. When fatigue is the life-limiting factor, the fatigue limit can be established by several increasing-load methods, such as a constant load increase to destruction, stepwise load increase to destruction, or cyclically increasing loads. Each of these methods has advantages for certain applications. Determining the fatigue limit by the critical stress method is of particular interest. This method depends on the energy hypothesis of fatigue, by which it has been established that the cyclic constant and the critical number of cycles are constant for a given type of metal. No specific recommendations are made, and the article represents a very general, qualitative discussion. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 17, 1967
- Accession Number
- AD0670095
Entities
People
- A. I. Kubarev
- K. P. Chudakov
Organizations
- National Air and Space Intelligence Center