On the Finite Element Free Vibration Analysis of Delaminated Layered Beams: A New Assembly Technique

Table 2

2nd frequency () of the delaminated beam, with a split occurring symmetrically about the midsection along the midplane; proposed FEM, DSM, CM, and standard FEM models.

Delamination length; /	Six 2-node FEM^†; elements	Ten 2-node FEM^†; elements	DSM [27]	Wang et al. [6], reported by [31]	Della and Shu; [31]	Layerwise; FEM [17]
	Mode 2	Mode 2	Mode 2	Mode 2	Mode 2	Mode 2
Intact	—	—	61.67	61.67	61.67	61.61
0.1	60.77	60.76	60.80	60.76	60.76	60.74
0.2	56.01	55.99	55.99	55.97	55.97	55.95
0.3	49.05	49.03	49.00	49.00	49.00	48.97
0.4	43.95	43.90	43.89	43.87	43.87	43.86
0.5	41.57	41.55	41.52	41.45	41.45	41.50
0.6	41.08	41.04	41.03	40.93	40.93	41.01

^†Conventional FEM displays numerical instabilities with delamination lengths approaching 0.