Week 9 - Attachment Feature Creation - Challenge 2

Objective: The main aim of this challenge is to create B-side features of the 'Door Trim', with the help of CATIA V5.

Overview: Created a 2.5mm solid part body of door trim with the help of class A surface, and created a B-side attachment feature 'Dog House' by considering the design parameters.

Tooling axis:

To create the tooling axis initially, I extracted the surface of class A with no propagation and I created the point at the centre of the extracted surface and created a line at that point in the Y direction. After creating the Tooling axis, I performed a draft analysis for class A to check the draft angle for it.

Class A surface and Tooling axis:

Draft analysis for class A:

To perform the draft analysis in class A, I selected the featured draft analysis tool in the Generative shape design workbench. Initially, I click on the 'use of the compass to define the new current draft direction' command to align the compass to the tooling axis.
Once the compass is aligned to the tooling axis, we need to select the surface which we need to perform a draft analysis. Class A surface will be highlighted (in green colour) according to the colour bar angle and colours we defined in it.
Here I gave green colour for 3 deg, red colour for < 0deg and blue colour for less than 0.9deg and greater than 0deg.
If I gave a 3deg draft angle some faces are not getting cleared, so I have gradually reduced the draft angle to up to every face gets cleared.

Some faces in the class are not get cleared with a 3deg draft angle, even if we give less than a 1deg draft angle. This happened because the faces which are not clearing with less than one degree also are not drafted properly while creating a class A surface.

Draft angle 0.5 deg:

Class B surface creation:

To create the class B surface for the door trim, I offset the class A surface to 2.5mm inside. Once the class A surface offset is created according to the thickness, we can observe some patches on the offset surface due to the fillets on the class A surface. Now, we need to close those patches. I used multi-section solid command to close the patches.

Class A offset:

I observed a few patches on the offset, I used a multi-section solid command to close the patch to create the proper 'Class B surface'.

Class A offset patches:

Class B surface:

Class C surface creation:

I used the sweep command in the geometric shape design workbench to create the class C surface.
Initially, I extracted the edges of the class A surface with tangent continuity by using the multiple extract command. After extracting the class A surface edges correctly, I sweeped the extracted edges with 93deg toward the class B surface. After sweeping the extracted class A surface edges, I extrapolated the edges of the sweep for 2mm to intersect the sweep edges with each other. Now I trimmed the extrapolated surfaces together to create a complete sweep surface towards the class B surface. I joined both the trimmed sweep surface and class A surface together, to get the class A+C surfaces as a single surface. Now, to create a solid body for the door trim we need a closed surface. I trim the class B surface with joined class A+C surface to make the closed surface of a door handle.

Class C surface:

Creating a Solid body of DOOR TRIM:

To create the solid body I used the closed surface command in the part workbench. Click on the closed surface command in the part workbench and give the closed surface as an input to create the solid part body.

Solid-body of Door Trim:

Dog House Design -

To create a dog house i created a scetch on plane and then extrude it upto 15 mm upward and 1 mm dawnward so the surface intersect properly. Then By using thicken command create a solid surface of dog house 2.5mm, then to create a C section of dog house i offseted xtruded surface 1(30-40% of wall thickness) mm inside and hight kept 5 mm from base as per design rule. Then proide 1.5 degree draft angle to side walls.

Solid part body including dog house:

Draft analysis for the solid part body:

To perform the draft analysis for the solid part body (which has Dog Houses on it), I used the featured draft analysis tool in the generative shape design workbench. Initially, I aligned the compass to the tooling axis and I selected the solid part body, I gave a 3deg draft angle in the colour bar. Even if I gave less than a 2deg draft angle in the colour bar some faces are not clearing properly, due to the class A surface draft angle and curvatures on it. the solid body has shown in red and blue colours even though we gave 0.9 deg in the draft angle in the colour bar we can't decrease the draft angle to less than 0.5deg because the draft angle for the plastic component is 0.5deg to 3deg).

0.5 deg draft angle:

Tree Structure used for Design -