疲劳试验
一种将大量试样测试至疲劳失效以确定疲劳特性的试验。疲劳试验分为两类（取决于试验试样）—
- 形状简单的试样，用于确定被测材料的疲劳特性。可在不同应力下测试不同试样，从而建立 S‑N 曲线。或者，也可在单一应力下测试所有试样，以便比较不同材料。这类超声疲劳试验使用专门设计的疲劳试验变幅杆。
- 形状复杂的试样（例如完整零件，如应用变幅杆）。这类试验用于比较不同设计。由于试样成本较高，这类疲劳试验往往只在单一应力水平下进行。
Fatigue test
A test in which in which a numerous specimens are tested until fatigue failure to determine the fatigue characteristics. Fatigue tests fall into two categories (depending on the test specimens) —
- Specimens with a simple shape so that the fatigue characteristics of the test material may be determined. Different specimens may be tested at different stresses so that an S‑N curve can be developed. Alternately, all specimens may be tested at a single stress so that different materials can be compared. Ultrasonic fatigue tests of this type use specially designed fatigue test horns.
- Specimens with a complex shape (e.g., a complete part such as an application horn). These tests are used to compare different designs. Because of the cost of the specimens, these fatigue tests are often conducted at only a single stress level.