Mesh the plastic side-door component of a car and perform mesh quality checks

OBJECTIVE : Mesh the plastic side-door component of a car and perform mesh quality checks

Follow the Quality Criteria and mesh the following component and assign thickness:

Target Element Length = 4mm

S.N	Quality Criteria	Value
1	Aspect Ratio	5
2	Skewness	45
3	Warping	15
4	Taper	0.5
5	Min. Length	2mm
6	Max. Length	6mm
7	Min angle Quad	45
8	Max angle Quad	135
9	Min angle Tria	20
10	Max angle Tria	120
10	Tria %	10

COMPONENT : The given component for this task is a trimmed side door of a car which is meant for crush-worthiness analysis.

• It was observed that the side door had different thickness from 2mm to 6mm
• There was solids and parts with thickness over 6mm. These parts are ignored and not considered for meshing.
• This plastic material has very small thickness so it is required to mesh by generating midsurface and because of the varying thickness , manual midsurfacing should be used

PROCEDURE

• IMPORT GEOMETRY EXTRACT MIDSURFACE

1. The geometry is imported into hypermesh radioss module. A general cleanup is done on the surface to fix broken edges and to prepare the component for meshing.
2. Defilleting and defeaturing of certain edges and lines are done on the component. Small fillets less than 2mm are removed to prevent elements from failing the minimum element size of 2mm.

• The geometry is very complex so the mid-surface is going to be extracted manually.
• The geometry is divided into four separate sections using split nodes.
• The solids with thickness of 6mm ad above are ignored.
• Midsuface is generated by offseting the surface across a distance and all errors and unequivalenced surfaces are fixed and merged.
• Lines are toggled and deleted as a pre-requisitefor meshing.
• Ribs and other surfaces are extendend onto the surfaces using surface edit and line drag option
• Tools used are ( Toggles lines, surface offset, distance ,organise , replace node,add/remove nodes, lines extend , drag surface ,trim with line/node/nodes, rule surface, filler surface).

• MESHING THE PLASTIC COMPONENT
• After midsurface is extracted, the meshing of the part is to be done
• Meshing is done by meshing one component after the other.
• Meshing is done with a target element of 4mm of minimum and maximum of 2mm and 6mm respectively.
• Tool Used : 2d Automesh

ELEMENT QUALITY CHECK

• Elements are optimised to be within a the criteria set by the instructor which can be seen at the objective section of this report.
• The element quality is improved by using various cleanup tools. Below are some of the tools used.
• Remesh elements
• Drag trias
• Edit elements-( Create ,split,combine)
• Smooth
• Project nodes- Used to project nodes to keep elements on the feature lines
• Eliminating trias ( Removing rotational quad, eliminate trial elements attopological edges,trials adjacent to each other,opposite trials.
• Final image of all elements passing given criteria below.
• Equivalence of elements is checked to make sure all elements are connected well with each other because its important in similations. Below is an image of the check

CONCLUSION

It is important to covert the 2d meshed element into 3D. The meshed elements are assigned properties based on their thickness and assigned specifically to the various components.

Properties of components

2D elements assigned thickness (View with 2d detailed element representation)

FINAL IMAGE OF MESHED PLASTIC SIDE DOOR