Applications of Symmetric and Nonsymmetric MSSOR Preconditioners to Large-Scale Biot's Consolidation Problems with Nonassociated Plasticity

Table 2

Performance of different solution schemes for the flexible footing example.

Load step no.	Number of nonlinear iteration	Average iterations for each linear system	Total solution time (hours)
Scheme 1: Newton + QMR preconditioned by nonsymmetric MSSOR
1	1	1940	0.137
2	4	1755	0.494
3	5	1756	0.624
4	5	1732	0.625
5	6	1723	0.751
Total	21	—	2.662
Scheme 2: IS (Chen) method + SQMR preconditioned by symmetric MSSOR
1	1	1060	0.061
2	4	780	0.180
3	5	780	0.241
4	6	793	0.308
5	6	753	0.317
Total	22	—	1.129
Scheme 2: 𝐾𝐺 (Chen) method + SQMR preconditioned by symmetric MSSOR
1	1	1060	0.060
2	4	845	0.182
3	4	865	0.189
4	4	855	0.200
5	5	860	0.256
Total	18	—	0.903