In previous chapters you explored the basics of explicit dynamics
procedures; in this chapter you will examine this topic in greater detail.
The explicit dynamics procedure can be an effective tool for
solving a wide variety of nonlinear solid and structural mechanics problems. It
is often complementary to an implicit solver such as
Abaqus/Standard.
From a user standpoint, the distinguishing characteristics of the explicit and
implicit methods are:
Explicit methods require a small time increment size that depends
solely on the highest natural frequencies of the model and is independent of
the type and duration of loading. Simulations generally take on the order of
10,000 to 1,000,000 increments, but the computational cost per increment is
relatively small.
Implicit methods do not place an inherent limitation on the time
increment size; increment size is generally determined from accuracy and
convergence considerations. Implicit simulations typically take orders of
magnitude fewer increments than explicit simulations. However, since a global
set of equations must be solved in each increment, the cost per increment of an
implicit method is far greater than that of an explicit method.
Knowing these characteristics of the two procedures can help you decide
which methodology is appropriate for your problems.