Week 9-Creation of 1D Connectors Challenge

                              WEEK-9

    CREATING CONNECTORS IN HYPERMESH

 OBJECTIVE:

• To mesh the given geometry according to quality parameters
• To create connectors at the different joints and attach the various parts in the given model

Quality Criteria Used:

Target Element size - 5 Units

PROCEDURE:

• Import Geometry: Go to File >> Import >> Model/Geometry

                                                                                                                Imported geometry

Mesh Generation:

• Mesh each surface individually according to quality parameters
• Improve mesh flow and clear off elements and opposite trias
• It is important to note that creation of some connectors destroy mesh flow
• After generating the connectors, the mesh needs to be modified for good mesh flow and satisfying all quality parameters

                                                                                                                            Meshed geometry

CONNECTORS:

 Connectors are elements that are used to represent connections between other geometrical entities. Hypermesh offers different types of connectors in 1D, 2D, and 3D for this purpose. It includes weld, adhesives, bolts, area contact 

1. Right_Rail_2 & Front_truss_1: - Seam-Quad (angled + capped + L)

• Select 1D/2D → Connectors → Seam option. Select the required options as shown below and create
• Tolerance value is the distance between 2 components
• The green line represents a successful connection
• We need to remesh that area where the connection is realized

                                                                                            Connection is realized but the mesh is distorted

• Clear all the trias possible and rectify all quality issues also
• We need to do this whenever we create any connection

                                                                                                              Mesh flow after re-meshing

2. Left_Rail_2 & Front_truss_1: - Quad elements

                                                                                       Seam Quads connection is realized

3. Front_truss_2, Front_truss_1 & Right_Rail_1: - Spot weld with 2 Layers and 5 mm Diameter

                                                                                                         1st layer of spot weld connection

                                                                                                       2nd layer of spot weld connection

    4. Front_truss_2, Front_truss_1 & Left_Rail_1: - Hexa (Adhesive)

                                                                                                Hexa Adhesive connection realized between 3 components

5. Rear_truss_2 & Right_Rail_2: - Bolt Connector

                                                                                     General Bolt connection

                                                                            Mesh flow after re-meshing

6. Rear_truss_2 & Left_Rail_2: - Bolt Connector

                                                                                                              General Bolt connection

                                                                                                           Mesh flow after re-meshing

7. Right_Rail_1 & Right_Rail_2: - Spot-weld with Rigid Elements

                                                                                                         Spot weld with rigid type connections

                                                                                                             RBE2 elements

8.  Left_Rail_1 & Left_Rail_2: - Spot-weld with Spring Elements

                                                                                                         Spot with spring elements are realized

                                                                                                 Spring (CELAS1) Elements

9.  CWeld (General):

                                                                                                            Cweld general connection realized

                                                                                                                        Cweld elements

10. Spot Penta (mig) Connection:

• This connection consists of a combination of RBE3 rigid elements and Penta mig solid components

                                                                                                    Penta (mig) Connection realized

Note:

• RBE3 elements usually give us better results than RBE2 elements
• RBE2 are rigid elements that induce  excessive stiffness to the model and they will give us bad results
• Whereas RBE3 elements are not actually rigid elements, they only transfer the load without any stiffness in the model.

11. Rigid Links:

                       Rigidlnk connection realized                                                                        RBE2 rigid elements

12. Seam Hexa Adhesive Contact Connection:

                                                                                                       Hexa Adhesive Contact Connection Realized

Learning Outcome:

• Aware of all the quality criterias and quality parameters during mesh generation.
• Improved mesh flow and removed trias, rotating quads to achieve better mesh flow
• Understood how to realize various connections using hypermesh

                                 Quality index                                                                                        Connections under Model tab

Conclusion:

All the required connections are successfully realized for the given geometry. The mesh flow is good. There are no quality issues.