3.28.2. User Defined Modal Data Format (UDMF)

FE Modal data can be imported based on an ASCII file that has the *.udmf extension (UDMF file). The UDMF file must be accompanied by the corresponding UDFF, and must have nodal mass, master node, eigenvalue, and eigenvector information.

A UDMF file consists of a basic information block, node coordinate block, nodal mass block, master node block, eigenvalue block (frequency) and eigenvector block (mode shape). All commands and data should be comma-separated. Each block's data specifications are noted in table below.

Figure 3.178: Available commands and data for UDMF

Block Category	Identification Command	Data Format
Basic information block	NoOfNode	Total number of nodes (integer)
	DOFperNode	6 (integer), fixed
	NoOfMasterNode	Total number of master nodes (integer)
	NoOfMode	Number of modes (integer)
Node coordinate block	NodeInf	NodeInf, 1^stNode Id(integer), x-coordinate (real), y-coordinate (real), z-coordinate (real), ~ N^th Node Id(integer), x-coordinate (real), y-coordinate (real), z-coordinate (real),
Nodal mass block	NodeMass	NodeMass, 1^stNode Id(integer), mass (real), ~ Nth Node Id(integer), mass (real),
Master node block	MasterNode	MasterNode, 1^stMaster node Id(integer), ~ N^th Master node Id(integer),
Eigenvalue block	ModeFreq	ModeFreq, 1, 1^stmode frequency (real) ~ N, N^th mode frequency (real)
Eigenvector block	ModeShape	ModeShape, NoOfModeShape,1, 1^stnode translational x-direction mode, 1^stnode translational y-direction mode, 1^stnode translational z-direction mode, 1^stnode rotational x-direction mode, 1^stnode rotational y-direction mode, 1^stnode rotational z-direction mode, ~ N^th node translational x-direction mode, N^th node translational y-direction mode, N^th node translational z-direction mode, N^th node rotational x-direction mode, N^th node rotational y-direction mode, N^th node rotational z-direction mode, ~ NoOfModeShape,N, N^th mode shape vector ~

Figure 3.179: Example of UDMF

Example of UDMF

NoOfNode,20,

DOFperNode,6,

NoOfMasterNode,2,

NoOfMode,24,

NodeInf,

1,6,3,0,

16,3,0,0,

17,0,1.500000013,1.500000013,

18,8.999999613,1.500000013,1.500000013,

19,0,1.500000013,1.500000013,

20,8.999999613,1.500000013,1.500000013,

NodeMass,

1,5.2987500000011e-08,

16,5.2987500000011e-08,

17,0,

18,0,

19,0,

20,0,

MasterNode,

17,

18,

ModeFreq,

1,0,

24,416644.33955303,

ModeShape,

NoOfModeShape,1,

-522.9518387646,

-372.31861109964,

283.68603123414,

NoOfModeShape,24,

-439.49400919414,

-167.9840536398,

-543.88913548453,

Figure 3.180: Example of Imported UDMF