Nondestructive indication of fatigue damage and residual lifetime in ferromagnetic construction materials

摘要

A new revolutionary attitude towards investigaudtion of fatigue damage in cyclically loadedudsteel samples is reported. The measurement isudbased on the method of Magnetic adaptiveudtesting, which – in contrast to traditional magnetic hysteresis investigations – picks up theudrelevant information from systematic measurudement and evaluation ofudwhole minor magneticudhysteresis loops and their derivatives. Satiudsfactory correlationsudbetween nondestructivelyudmeasured magnetic descriptors and actual lifeudtime of the fatigued material were found. Theudpresented method is able to servude as a powerful tool for indicatiudon of changes, which occur inudstructure of the inspected objects during their inuddustrial service lifetime, as long as they areudmanufactured from ferromagnetic material