Roof Design

Aim:We are designing the roof with the help of NX-sheet metal design.

Procedure:

1. with the help of styling surface we plan to design the roof.

2.Then we create the feature group for further design.

3.We then use the assembly work bench for creating all the various parts in the assembly format as follows:

• Outer roof pannel.
• Front roof inner pannel.
• Rear roof iner pannel.
• Middle Bow roof.
• Rear rail bow roof.

4.As taking the referance of styling surface we need to design the outer roof pannel as shown in the figure.

Outer roof pannel:

5.As per the attached images we completed the roof outer pannel.

Front roof inner pannel:

6.Next we need to create the another assembly in the name of front roof inner pannel.

7.Then with the reference of the styling surface we need to offset the surface as shown in the figure.

8.Then we need to similarly offset other surface as per design standards as shown in the below figure.

9. For trimming purpose we need to offset the cuves on surface as shown in the figure.

10. Then we need to trim the front roof inner pannel in a nice shape with the help of trim command as shown in the figure.

11.To strengthen the front roof inner pannel we need to create the emboss as shown in the figure by keeping the minimum angle and offset criteria in mind as.

12.Finally thicken the surface as shown in the figure.

Rear roof inner pannel:

• Then we need to take a reference of the styling surface and the offset the surface as shown in the figure.

• Next we need to trim the unwanted sheet part by taking a reference of offset curve on face as shown in the figure.

• Next step is to join the trimmed and offset surface with the help of through curve as shown in the figure.
• We need to vanish the sharp edges with the help of blend option as shown in the figure.
• For strengthening the surface we need to give the emboss as shown in the figure.

• Finally we have created the rear roof inner pannel as shown in the figure.

Middle and Rear Bow roof rail:

• Then we need to take a reference of the styling surface and the offset the surface as shown in the figure.

• Next we need to trim the unwanted sheet part by taking a reference of offset curve on face as shown in the figure.

• Next step is to join the trimmed and offset surface with the help of through curve as shown in the figure.

• Then we need to join the offset surface withe the help of studio splin as shown in the figure.

• Finally we have completed the rear bow roof and middle bow roof by keeping all the standard design condition and tolarences in the mind.

Final Roof Design:

• Conclusion:Finally we have completed the roof design by considering all the design condition in mind with the help of NX_Sheet_Metal Design.

Calculation:

• We had to calculate two calculate two condition satisfaction as mentioned below:
• Bow–Roof Prediction Formula:

Bow–Roof Prediction Formula
	Rx	Ry	L	l	R	t	W	CONDITION	SATISFACTION
Case-1	3247.62	4158.19	1921.94	492.46	1823.46	0.75	1.26	<2.7	YES
Case-2	3018.36	3139.44	1921.94	519.7	1538.85	0.75	1.268	<2.7	YES
Conclusion:As per above data we found that the designed bow roofs satisfies the condition

Note:As we have the sunroof we have only considered two cases.

Snow load Condition formula:

Snow load Condition formula
	Ly	Lx	t	Rx	Ry	y	L1	L2	Iy	My	α	S	Qr	Condition	SATISFACTION
Case-1	2025	1119	0.75	3357	7562	918	380	350	1.168	1016226	1.27	365	4.8	>3.1	Yes
Case-2	2025	1119	0.75	3158	7342	876	450	330	1.168	1006524	2.27	390	3.9	>3.1	Yes
Conclusion:As per above data we found that the designed bow roofs satisfies the condition

Draft Analysis:

• After completion of designing the roof we need to do an design analysis which is called draft analysis.
• We perform draft analysis for all the designed parts to check the tool positioning and the machinability of the parts.
• The designed roof should not contain any defaulted parts.
• Minimum criteria should be maintained for getting accurate design but then also in some case we get some errors which we need to clear by doing draft analysis as shown in the below figure.

• There are three color criteria mentioned below:

1. Green: Very good
2. Yellow: good
3. Blue: Not good
4. Red: Not acceptable

Conclusion :Finally we have completed the roof design with the help of NX_Sheet metal design wihout any defects in design and the designed roof is manufacturable.