====== LSTIFF ======

===== Description =====

Constitutive law defining a concentrated stiffness at one node, onde degree of freedom, possible use as a linear spring.

==== The model ====

Definition of a stiffness at one DOF, useful in case of contact solid-solid where one solid has only the stiffness issued from the contact elements.\\

In case of pilot node, it gives a stiffness and a stress to the foundation outside any contact occurrence. Only the element STIFF uses this law.

==== Files ====

Prepro: LLSTIFF.F \\

===== Availability =====

|Plane stress state| YES |
|Plane strain state| YES |
|Axisymmetric state| YES |
|3D state| YES |
|Generalized plane state| YES |

===== Input file =====

==== Parameters defining the type of constitutive law ====

^ Line 1 (2I5, 60A1)^^
|IL|Law number|
|ITYPE| 97|
|COMMENT| Any comment (up to 60 characters) that will be reproduced on the output listing|

==== Integer parameters ====

None.

==== Real parameters ====

^ Line 1 (3G10.0) ^^
|STIFF| Value of the concentrated stiffness term |
|$\alpha$| 2D angle to define direction of spring when IDDL = -1 (see [[elements:stiff|STIFF]] element) |
|$\beta$| Idem for 3D analysis |