# Other baspl++ Objects

## 1. B2000++ Helper Objects

The following objects are intended to be used together with B2000++ databases.

### 1.1. The ViewEBC Python Object

The ViewEBC object displays essential boundary conditions (EBC), such as displacement constraints or temperatures, at the mesh nodes for one of more cases or for one or more essential boundary condition sets. All essential boundary conditions at a given node are displayed in the form of a string xxx..., where any of x is either F (free), L (locked, i.e. degree of freedom is set to 0.0), or V (the degree of freedom has a prescribed non-zero value). The first character in the string refers to the first degree of freedom, the second one to the second, and so on.

The following example displays all essential boundary conditions defined by the computational case 1 of a model. Start with opening a model an extracting all elements (by edges):

m = Model(...)     # Create a Model with a B2000++ database
p = NPart(m)       # Create a NPart
p.edge.show = True # Show all element edges
p.elements.extract = True # Of all elements

Create a ViewEBC object and view all essential boundary condition sets specified in case 1:

n = ViewEBC(m, cases = 1)

Note Essential boundary conditions of a case and computational cycle can be viewed with the contour or vector viewing methods of an NPart. But be aware that all EBC sets defined for the specific case are viewed.

### 1.2. The ViewNBC Python Object

The ViewNBC object displays natural boundary conditions (NBC), such as forces, pressure, traction forces, temperatures for one or more cases or for one or more NBC sets. In the current version only the nodes, element edges, or element faces are displayed in specific colors, without any values. See note below if values are to be included in the viewing process. Nodes are displayed as square dots, element edges as lines, and element faces as polygons. If color specification is omitted an internal color scheme is used to display nodes, edges, or faces.

The following example displays the location of all natural boundary conditions of the computational case 1 of a model. Start with opening a model an extracting all elements (by edges):

m = Model(...)     # Create a Model with a B2000++ database
p = NPart(m)       # Create a NPart
p.edge.show = True # Show all element edges
p.elements.extract = True # Of all elements

Create a ViewNBC object and view all natural boundary condition sets specified in case 1:

n = ViewNBC(m, cases = 1)

The result is displayed in the figure below.

Note Natural boundary conditions of a case and computational cycle can be viewed with the contour or vector viewing methods of an NPart. But be aware that all NBC sets defined for the specific case are viewed

### 1.3. The ViewLINC Python Object

The ViewLINC object graphically displays constraint equations defined by the LINC (linear constraints) datasets. Constraint equations are also known as multi-point constraints (MPC).

The following example displays the location of all natural boundary conditions of the computational case 1 of a model. Start with opening a model an extracting all elements (by edges):

m = Model(...)     # Create a Model with a B2000++ database
p = NPart(m)       # Create a NPart
p.edge.show = True # Show all element edges
p.elements.extract = True # Of all elements

Create and view a ViewLINC object, assuming the default LINC dataset identifier 0:

n = ViewLINC(m)

### 1.4. The ViewEPATCH Python Object

The ViewEPATCH object displays the shape and the components of an EPATCH mesh. Components are the EPATCH patch vertices (Px), the edges (Ex), and the faces (Fx).

The following example displays the location of all natural boundary conditions of the computational case 1 of a model. Start with opening a model an extracting all elements (by edges):

m = Model(...)     # Create a Model with a B2000++ database
p = NPart(m)       # Create a NPart
p.edge.show = True # Show all element edges
p.elements.extract = True # Of all elements

Create a ViewEPATCH object and view the EPATCH with identifier 1. Show the patch point, face, and edgeidentifiers:

v=ViewEPATCH(m, ident = 1)
v.show_point_idents=True
v.show_face_idents=True
v.show_edge_idents=True

The result is displayed in the figure below.