Papers by Keyword: Test Conditions

Abstract: There are many methods of testing elastic wave velocities of engineering rockmass such as the elastic wave penetration test between adits, elastic wave test on the adit wall and the borehole sonic method etc, but the test results vary with different test methods. It is important to understand and apply appropriately the test results. Based on the field tests, the characteristics of elastic wave velocities under different test methods are studied. The research indicates that the main influence factors of different test methods on wave velocities include the rockmass occurrence environments and the test conditions. For the elastic wave penetration test between adits, the rockmass occurrence environments are basically unchanged, and the influences of the test conditions are little, so the wave velocity obtained by this method is more scientific. The study results are important for the reasonable evaluation of engineering rockmass.

Abstract: The paper discusses the problem of reliability calculation for mechanical units under load. Because the rated reliability of the unit as a system with many independent elements can tend to zero, the methods of reliability calculation of the units as real objects with the common factors (loads, operation conditions) are proposed. The choice of the life test modes and test time depends essentially on unit-related information like their operation conditions. The paper describes one of approaches, passing to this problem. Within its framework, the accumulations of damages are made at several typical points of the loaded system.