Block Format Keyword Defines a spring element. It is used for modeling connection. The spring properties are applied to the local spring coordinate system.


(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
sprg_ID node_ID1 node_ID2 node_ID3 node_ID4 node_ID5 node_ID6     Skew_ID


Field Contents SI Unit Example
part_ID Part identifier of the block.

(Integer, maximum 10 digits)

sprg_ID Element identifier.


node_ID1 Node identifier 1 for spring.


node_ID2 Node identifier 2 for spring.


node_ID3 Node identifier 3.


node_ID4 Node identifier 4.


node_ID5 Node identifier 5.


node_ID6 Node identifier 6.


Skew_ID Optional: Skew system identifier.

Only used when the spring is defined using /PROP/TYPE8 (SPR_GENE) or /PROP/SPR_MAT (TYPE23) with /MAT/LAW108 (SPR_GEN). 8




  1. The identifier must be unique in each element family, but it is advised for each element type to have a unique element identifier in the global model.
  2. More than one spring block can be used to define a part.
  3. Any number of springs can be defined in one block.
  4. Spring elements with /PROP/TYPE8 (SPR_GENE) or /PROP/TYPE23 (SPR_MAT) with /MAT/LAW108 (SPR_GENE) may have a length equal to 0.
  5. Spring elements with /PROP/TYPE12 (SPR_PUL), /PROP/TYPE13 (SPR_BEAM), /PROP/TYPE23 (SPR_MAT) and /PROP/TYPE13 (SPR_BEAM) with /MAT/LAW113 (SPR_BEAM) should have a non-zero length.
  6. Spring element is defined with two nodes: node_ID1 and node_ID2.
    The plane XY is defined with the three nodes (node_ID1, node_ID2, and node_ID3); the third node, node_ID3 defines the Y direction also for the non-symmetric spring (/PROP/TYPE13 or /MAT/LAW113).

    Figure 1.
  7. Both node_ID5 and node_ID6 are reserved for future use for new joints types.
  8. For spring elements using /PROP/TYPE8 (SPR_GENE) or /PROP/SPR_MAT with /MAT/LAW108, the local system can be defined for each element using /SPRING Skew_ID. If Skew_ID is not defined for each element, the local system defined in /PROP/TYPE8 (SPR_GENE) or /PROP/TYPE23 (SPR_MAT) Skew_ID is used. If a system is not defined in the element or property, then the global system is used.