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--- doc:user:conditions:dead_loads [2015/01/08 15:49] – boman
+++ doc:user:conditions:dead_loads [2016/03/30 15:23] (current) – external edit 127.0.0.1
@@ Line 1: / Line 1: @@
-====== "Dead" Loads ======
-{{:doc:user:ico-advanced.png?40 |Advanced}}
+====== Prescribed Nodal "Dead" Loads ======
-Dead loads are forces that are directly prescribed at the nodes of the mesh. The amplitude and direction of such forces is known a priori.
+ {{:doc:user:ico-advanced.png?40|Advanced}}{{:doc:user:ico-danger.png?40|Danger!}}
+Dead loads are forces that are directly prescribed at the nodes of the mesh. The amplitude and direction of such forces is known a priori. In particular it is independent from the deformation of the underlying material. Such forces also strongly depend on the chosen mesh desnity. Changing the mesh usually requires a complete redefinition of these forces.
-<note important>It is usually a bad idea to define dead loads in a model.</note>
+<note important>As a consequence, it is usually a bad idea to define nodal "dead" loads in a model. To model realistic loads (pressure and shear) which depend on the deformed configuration and do not depend on the mesh density, use [[doc:user:elements:boundaries:pressure_shear]].</note>
-To model a loads (pressure and shear) which depends on the deformed configuration, use [[doc:user:elements:boundaries:pressure_shear]].
+Anyway, the command used for the definition of "dead loads is the same as [[doc:user:conditions:displacements]] except that [[doc:user:general:locks|Field1D]] refers to a force instead of a displacement.
-The command is the same as [[doc:user:conditions:displacements]] except that [[doc:user:general:locks|Field1D]] refers to a force instead of a displacement.