When loads are applied relatively quickly (faster than 1/3 of the lowest natural frequency) or are applied repeatedly, static analysis may be inadequate. For seldom occurring transient loads the objective is usually to calculate the maximum response. For repeated loads, an estimation of fatigue life is a common requirement. These analyses fall into the category of dynamic analysis and typically involve one or more of the following:
- Calculation of natural frequencies and mode shapes
- Harmonic analysis (also known as forced response) for cyclic loading
- Dynamic Load Factor (DLF) estimation - for estimating maximum response from a static analysis for seldom occurring transient loads