A CONCURRENT EXPLICIT IMPLICIT ALGORITHM IN STRUCTURAL DYNAMICS

A concurrent explicit-implicit algorithm for time integration of the d ifferential equations arising from a finite element discretization is described. The first step of the method consists of partitioning the f inite element mesh into subdomains. As a consequence of this partition , the nodes in the resulting mesh form two distinct sets: interior nod es and interface nodes. Once these sets of nodes are identified, the m ethod proceeds by integrating the interface nodes explicitly, and the interior nodes implicitly. Since the interior nodes in a specific subd omain are not shared by any other subdomain, they can be integrated in dependently. As a direct consequence, concurrency is introduced. Thus, this method is very well suited for implementation in parallel comput ers. In addition to this feature, the concurrent explicit-implicit alg orithm is also expected to speed up computations, even on a sequential computer, by reducing the equation solving effort. Some consideration s on the conversion of an originally sequential finite element analysi s program to implement this method is given. Numerical examples are pr esented to illustrate the method.