Väsymystesteillä

Väsymystesteillä, commonly translated as fatigue testing, refers to a range of tests designed to evaluate the resistance of a material, component, or structure to failure under cyclic loading. Unlike static tests that apply a single load, fatigue tests subject the specimen to repeated applications of stress or strain over time. The primary goal is to determine the fatigue life, which is the number of cycles a material can withstand before a crack initiates and propagates to failure.

These tests are crucial in engineering design, particularly for applications where components experience repeated stress during their operational life. Examples include aircraft wings, bridges, vehicle chassis, and rotating machinery parts. By understanding how materials behave under fatigue conditions, engineers can predict component lifespan and design them to be safe and reliable.

There are various methods for conducting fatigue tests. Common techniques involve applying tensile, compressive, bending, or torsional loads cyclically. The amplitude of the applied stress or strain, the frequency of the cycles, and the presence of environmental factors like temperature or corrosive substances can all influence the fatigue life. Data from fatigue tests are often presented in S-N curves (stress-number of cycles), which plot the stress amplitude against the number of cycles to failure. These curves help in determining the fatigue limit or endurance limit, the stress level below which a material can theoretically endure an infinite number of cycles without failing.