Lastzyklus

Lastzyklus is a term used in engineering to denote the phase of a cycle during which an external load is applied to a component or system. In many applications a cycle comprises loading, unloading, and rest; the Lastzyklus specifically refers to the portion of the cycle when the load is active. The characteristics of a Lastzyklus are defined by the load magnitude (peak and mean), the duration of application, and the rate at which the load changes. These factors influence the stress amplitudes experienced by the part and affect fatigue life.

In structural and mechanical design, Lastzyklus data are used to assess durability under repeated service loading. Engineers collect or simulate load histories, count individual cycles, and analyze the distribution of amplitudes through methods such as rainflow counting. Fatigue damage is typically estimated with approaches like S-N curves and Miner’s rule, which relate the number of cycles at a given amplitude to the cumulative damage.

In practice, Lastzyklus appears in the design of bridges, aircraft components, automotive parts, and machinery, where understanding the most harmful portions of the loading history is essential for reliability. The term can also appear in testing protocols that apply cyclic electrical, thermal, or hydraulic loads, where the duration and magnitude of the applied load determine test outcomes.

Limitations include variability in loading histories and material responses; thus, safety factors and conservative assumptions are common. Understanding the Lastzyklus, in combination with overall cycle analysis, supports safer and longer-lasting designs.