5. B modeling#

5.1. Characteristics of modeling#

The elements are TRIA3 in plane deformation. 5 load cases are defined in the following way:

Load case 1: **** SPHERE **

	The side of an element is equal to \(2.5\) .The circle with radius 2. and centered at node 1 has a non-empty intersection with the elements shaded in the figure, i.e. \(\mathit{Tr6a}\), \(\mathit{Tr6b}\), \(\mathit{Tr7a}\), \(\mathit{Tr10b}\), \(\mathit{Tr11a}\) and \(\mathit{Tr11b}\) .We apply a volume force of density —1 according to \(y\) on this name zone \(\mathit{GM1}\) defined by using the « SPHERE » option from CREA_GROUP_MAde the DEFI_GROUP command and an opposite volume force on this zone defined in extension.

Load case #2: BANDE

	The elements of the hatched area i.e. \(\mathit{Tr5A}\), \(\mathit{Tr5B}\), \(\mathit{Tr6A}\), \(\mathit{Tr6B}\),, \(\mathit{Tr7A}\),, \(\mathit{Tr7B}\), \(\mathit{Tr8A}\), \(\mathit{Tr8B}\), \(\mathit{Tr9A}\), \(\mathit{Tr9B}\), BELGRADE, \(\mathit{Tr10A}\) \(\mathit{Tr10B}\) \(\mathit{Tr11A}\) \(\mathit{Tr11B}\), Tr12A, \(\mathit{Tr12B}\) define the intersection of the plate with the strip whose sides are parallel to the axis \(x\), whose middle passes through the node \(\mathit{N1}\), and whose half-width is equal to \(2\) .A volume force of density \(–1\) along is applied to this zone defined geometrically by name \(\mathit{GM3}\) by using the option « BANDE » of CREA_GROUP_MA from the DEFI_GROUP command and the volume force of density \(1.\) opposite to the previous one on this same zone defined in extension.

Load case #3: **** FACE_NORMALE **

	The list of elements of geometric type SEG2, \(\mathit{S1}\), \(\mathit{S2}\), \(\mathit{S3}\), \(\mathit{S4}\) is defined as the list of elements of the mesh perpendicular to the direction \(y\) .A pressure equal to \(–1\) is applied to this list of name \(\mathit{GM4}\) defined geometrically in the manner indicated, using the option « » FACE_NORMALE « of CREA_GROUP_MAde the command DEFI_GROUP and a press to \(1.\) on this same list defined in extension.

Load case #4: ENV_SPHERE

	Nodes 3, 5, 7, and 9 are defined as being the nodes of the mesh belonging to the intersection of the plate with the intersection of the plate with the center \(\mathit{N1}\) and radius \(2.5\) (this is the length of the side of an element) .This list of nodes with the name \(\mathit{GN1}\) is defined using the « ENV_SPHERE » option of CREA_GROUP_NOde the DEFI_GROUP command. We apply a nodal force \({F}_{y}\mathrm{=}–1\) in each of the nodes in this list and a \({F}_{y}\mathrm{=}1\) node strength in each of the nodes in the same list defined in extension.

Load case no. 5: PLAN

	Nodes 14, 15, 16, 17, and 18 are defined as belonging to the line passing through node 14 and whose normal is parallel to \(x\) .This list of nodes with the name \(\mathit{GN3}\) is defined using the « PLAN » option of CREA_GROUP_NOde the command GROUP_NO .We apply a nodal force \({F}_{y}\mathrm{=}–1\) to each of the nodes in this list and a nodal force \({F}_{y}\mathrm{=}1\) to each of the nodes in the same list defined in extension.

The mesh consists of 32 TRIA3 meshes and 4 SEG2 meshes.

We test the following options for creating a group of elements from the DEFI_GROUP command for 2D:

and the following options for creating a group of nodes from the DEFI_GROUP command for 2D: