Week 9-Creation of 1D Connectors Challenge
AIM:
To determine the given challenge.
OBJECTIVE:
To mesh the given geometry and create a 1D connections at desired locations using Hypermesh. The following connections are,
1. Right_Rail_2 & Front_truss_1:- Seam-Quad(angled+capped+L)
2. Left_Rail_2 & Front_truss_1:- Quad elements
3. Front_truss_2, Front_truss_1 & Right_Rail_1:- Spot weld with 2 Layers and 5 mm Diameter
4. Front_truss_2, Front_truss_1 & Left_Rail_1:- Hexa (Adhesive)
5. Rear_truss_2 & Right_Rail_2:- Bolt Connector
6. Rear_truss_2 & Left_Rail_2:- Bolt Connector
7. Right_Rail_1 & Right_Rail_2:- Spot-weld with Rigid Elements
8. Left_Rail_1 & Left_Rail_2:- Spot-weld with Spring Elements
9. Rest all the component left Join them with suitable connectors
PROCEDURE:
Import the .hm model and the connector points in the model tree are hidden while meshing.
Each individual component is seperated and meshed seperately.
If required the components can be cleaned for topological errors and defeatured using manual or autocleanup method.
To clean geometrical errors: Geom > Auto cleanup > Set parameters > Clean.
2D Surface Meshing and Mesh Refinement:
To generate a shell mesh over each component.
2D > Automesh > Surfs > Target length = 5 > specify elem type and order > mesh.
However to achieve a perfect mesh without quality errors the comp is sectioned into different surfaces using surf trim option and meshed separately.
Since volume tetras arent being generated the surfaces can be meshed with quads majority.
Similarly symmetrical components can also be trimmed about the mid point and meshed and reflected about the central axis.
Finally all components have been meshed using 2D elems.
ASSIGINING PROPERTY CARD:
A single property and material card is added for every comonent.
Assuming every comp has the identical thickness and material a single card is added to each.
To create a material card: Name = steel - Type = ISOTROPIC - Card = MAT1.
Then the necessary material values like poissons ratio, youngs mod,etc... are specified.
Similarly a new property card is created with the PSHELL card image and the above mat card is assigned to it.
The thickness of the comp are also specified in the property card.
Each card is assigned the property card which is linked to the material card.
1D Connections:
1.Seam-Quad(angled + capped + L):
For:Right_Rail_2 & Front_truss_1:
To create a seam weld: Connectors - seam.
Select the nodes on one of the component.
Tolerance = Specify the search distance(10mm).
Select the two components and keep the imprint check on.
Weld type is set as seam-quad
The weld angle can be altered but an angle of 60 or 45 is widely preferred based on the alignment of two components.
The spacing is set a 5mm. Spacing defines the distance between the two adjacent weld elements.
2.Seam-Quad elements:
For: Left_Rail_2 & Front_truss_1
To create a seam weld: Connectors - seam.
Select the nodes on one of the component.
Tolerance = Specify the search distance(10mm).
Select the two components and keep the imprint check on.
Weld type is set as seam-quad and the spacing is kept as 5mm.
3.Spot weld with 3 layers and 5mm diameter:
For:Front_truss_2, Front_truss_1 & Right_Rail_1
To create a spot weld:2D - connectors - spot - type = weld.
Select all the required nodes where the loaction of the spot weld has to be placed.
Then select all the 3 components.
Specify a diameter of 5mm and number of layer as 3.
4.Hexa(Adhesive):
For:. Front_truss_2, Front_truss_1 & Left_Rail_1
To create a seam weld: Connectors - seam.
Select the nodes on one of the component.
Tolerance = Specify the search distance(10mm)
Select the two components and keep the imprint check on.
Weld type is set as hexa under the weld type category.
The strips and coats of the weld can be altered. In this case the strip is set as 2 and a single coating is specified.
5.Bolt Connector:
For: Rear_truss_2 & Right_Rail_2
To create a bolt connector. Connectors - bolt.
Specify the location of the bolt by selecting two single nodes at a certain distance in one of the component since two bolt connectors are being realised.
Select the two components which has to be fixed by the bolt.
Select the option to create a hole to define the bolt as a physical element.
Specify the search length.
6.For:Rear_truss_2 & Left_Rail_2:
7. Spot-weld with rigid elements:
For:Right_Rail_1 & Right_Rail_2:
As similar to previous spot weld creation this spot weld is created using rigids instead of weld.
To create a spot weld: 2D - connectors - spot - type = rigids.
Select all the required nodes where the location of the spot weld has to be placed.
Then select all the 2 components.
Specify the diameter and number of layers as 2.
8.Spot - weld with spring elements:
For: Left_Rail_1 & Left_Rail_2:
Similarly as done for the previous case here the spot element type is a set as spring instead of rigid or weld.
9.For the other Components:
In case of the shell component with a hole a adhesieve connection is made.
Adhesives are RBE3 elements that distribute load applied to its master node. Unlike RBE2 elements RBE3 do not impart infinte stiffness to the component.
To create adhesives using area connector method:
2D - Connectors - Area - Type = Adhesive - Select elems and components - speecify coat layer - specify search tolerance - create.
Similarly a seam weld is created on other components.
A seam weld with a type is created.
2D - Connectors - Seam - Type=Seam - Quad.
Then specify the weld angle as 45 degree and selected required elems and components.
The realized connection is shown below.
FINAL OUTPUT:
Hence every components have been meshed and required connections have be defined and sucessfully realized.
OBSERVATION:
Thus the mesh of the given geometry and create a 1D connections at desired locations using Hypermesh is sucessfuly obtained.
RESULT:
Thus the given challenge is determined sucessfully.