ABSTRACT
Step-stress ALT is applied more widely in engineering, because it is more efficient than constant stress ALT, and easier to perform than progressive stress ALT. In step-stress ALT, specimens are first
c. Progressive stress ALT
a. Constant-stress ALT b. Step-stress ALT
d. Step-down-stress ALT
subjected to a specified constant stress for a specified length of time; after that, they are subjected to a higher stress level for another specified time; the stress on specimens is thus increased step by step[1∼8].
