A static analysis is sufficient if you are interested in the long-term response of a structure to applied loads. However, if the duration of the applied load is short (such as in an earthquake) or if the loading is dynamic in nature (such as that from rotating machinery), you must perform a dynamic analysis. This chapter discusses linear dynamic analysis in ABAQUS/Standard; see Chapter 9, “Nonlinear Explicit Dynamics,” for a discussion of nonlinear dynamic analysis in ABAQUS/Explicit.