DEFORM

Bulk Data Entry Defines enforced axial deformation for one-dimensional elements for use in statics problems.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
DEFORM SID EID1 D1 EID2 D2 EID3 D3    

Example

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
DEFORM 21 157 -0.2 111 1.4        

Definitions

Field Contents SI Unit Example
SID Identification number of a deformation set.

No default (Integer > 0)

  
EID# Element identification number. 1

No default (Integer > 0)

  
D# Deformation (Positive value represents elongation).

No default (Real)

  

Comments

  1. Only CBAR, CBEAM, CROD, CONROD, and CTUBE elements are valid.
  2. To be used in an analysis, deformation sets must be referenced by a DEFORM Subcase Information Entry.
  3. DEFORM does not enforce an actual extension of the length of the element; it applies an internal strain within the element, which produces the specified extension if the element is free to expand (similar to the effect of thermal expansion).

    Since most elements in an FEA model are not free to expand, the specified extension value may not be achieved because elastic compression of the element will partially or completely offset the effect of the prescribed strain. To precisely enforce an increase in length, MPC equations are more appropriate. Alternatively, giving the DEFORM element a very high axial stiffness can approximate such conditions.