Spring Elements

Spring elements may be defined in two ways; each spring can be defined individually by assigning a spring element variant to a FEMGEN point or line, or the command 'PROPERTY BOUNDARY ELASTIC' can be used to define a number of SPRING1 elements (placing a spring between a node and ground in a particular direction). The latter method is achieved via the following command:

PROPERTY BOUNDARY ELASTIC [const_name] part_name/ALL spring_const dir

Argument Meaning

const_name FEMGEN constraint name (optional).

part_name Any geometry containing nodes.

Spring_const Spring stiffness.

dir Degree of Freedom Indicator (1,2,3).

Notes:

1.

The interface will simply apply the same spring value to all nodes attached to the specified geometry.

2.

Note that it is not possible to generate spring elements between two parts of a structure via the 'PROPERTY BOUNDARY ELASTIC' command. In such cases, a number of FEMGEN lines should be used to connect the two parts.

Example FEMGEN Command:

PROPERTY BOUNDARY ELASTIC CO1 L4 200 1

Corresponding ABAQUS Input File:

               
*ELEMENT, TYPE=SPRING1, ELSET=SPL4  
   17 ,    21
   18 ,    16
   19 ,    11
   20 ,     6
   21 ,     1
*SPRING, ELSET=SPL4  
    1
  200.0000    ,