The divide and conquer approach of domain decomposition methods for the parallelization of engineering simulations has been very successful. This paper presents another implementation of this approach for seismic response analysis of a shield tunnel in Shanghai, China.

The problem is formulated using an explicit finite element method (FEM) approach; the reason for explicit time integration is to avoid the high-memory requirements of implicit schemes that require storing large matrices. Domain decomposition is achieved using two methods: a recursive coordinate bisection (RCB) method and a metis algorithm. Parallel performance of both methods is investigated, and the authors arrive at the obvious result of the metis algorithm being more efficient. The authors also suggest that their problem size (of the order of four million nodes) is huge; it is actually a nominal-size problem by today’s standards.

The paper presents nothing new about parallel programming; however, the finite element analysis of the shield tunnel is perhaps new. Considering that no validation of the method is reported, I would be wary of the results.