Roof Design

                                                                                           ROOF DESIGN

AIM = For the Given Roof styling, create an ASSEMBLY by developing the essential flanges for the outer roof and creating the reinforcements. Provide appropriate dimensions and check for Draft analysis. Do a curvature study on the roof and perform calculations to determine the position of the Bow-roofs.

• Suggest and implement remedies in the design if the criterion is not full-filling
• Start with the creation of a roof ditch area with a tool opening angle of 7 degrees.
• Develop the reinforcements as separate parts

DEFINITIONS

• Heat Distortion Analysis = Analysis used to find at what limit of temperature, the metal softens and deforms under a specific load. Mainly done to check the ability of the roof to withstand in high temperature wrt the position of the reinforcements.
• Snow Load Analysis = Analysis done to check the ability to withstand and deformation value of roof when the snow loads over it in snow fall regions. Roof design must pass these calculations to ensure its stiffness to withstand the physical and geographical conditions.

MASTER SECTIONS FOR DESIGNING

• FRONT ROOF

• REAR ROOF

• BOW ROOF

• CENTRE ROOF WHEN SUNROOF IS PRESENT

DESIGN CONSIDERATIONS OF A ROOF

• Visibilty Criteria
• Head Clearance
• Curvature Analysis
• Heat distortion and Snow load criteria
• Draft Analysis

SOFTWARE USED

• NX- CAD

REPORT 

• The objective of this project is to design car roof with  essential flanges and reinforcements  like ditch area , front roof rail , bow roofs, central roof rail and rear roof rail for the the given styling surface.
• The Class A- Surface of Roof Outer Panel, master sections and other design considerations are given was given.
• Initiated the process of creating Roof outer panel and given a fix constrain initially under design considerations, since it act as the highest parent in this drawing.
• Mostly, similar kind of tools are used like Wave Geometry linker, Untrim, Trim sheet, Offset Surface, Bridge Curve, Law extension, Through Curve Mesh, Sew, Edge blends, Datum Plane, line, Intersection Curve, Sketch, Project Curve, Extend Sheet, Mirror geometry, Thicken - for all the respective components created but varied in order and dimensions.
• Tooling Axis is created for each and every component separately.
• As per the master section, i had choosed the roof with Sunroof, for that a cutout has been provided over the panel under standard dimensions in OEM's.
• All the Sketches are perfectly underlined to segregated feature groups, with proper naming to understand.
• In respect to the completion of Roof Outer Panel, followed the creation of Front Roof Rail, Rear Roof Rail, Bow Roof Rail - 1, Centre Roof Rail with Reinforcements, and Bow Roof Rail - 2 in order.
• All the parts are created with respect to master section provided and design considerations.
• After the designing, Draft Analysis is conducted for each and every component with aminimum draft of 7 degrees and it cleares in a standard manner.
• Finally, the important process of Curvature study initiated with Heat Distortion, Snow Load analysis and ended with Sectional analysis as per design considerations.

IMAGES

• FINAL ASSEMBLY

• CALCULATION

HEAT DISTORTION ANALYSIS
SNOW LOAD ANALYSIS

• DRAFT ANALYSIS

ROOF OUTER PANEL

FRONT ROOF RAIL

REAR ROOF RAIL

BOW ROOF RAIL - 1

CENTRE ROOF RAIL

REINFORCEMENT SUPPORT FOR SUNROOF 

BOW ROOF RAIL - 2

CALCULATIONS

• Heat Distortion Analysis

                    Where,

                                 L = Roof Length in X-Direction[mm](Roof dimension in 0-Y)

                                 R = Roof curvature 

                                       Rx = X curvature

                                       Ry = Y curvature

                                 t  = Roof plate thickness [mm]

                                 l = Bow Roof Span [mm]

• Snow Load Analysis

                     t = Roof plate thickness [mm]

                    Ly = Distance between the front and rear roof Rails on the Vehicle along with 0Y[mm]

                             Length of Roof panel with the center point between Roof rail Front /Rear as the front and rear reference point.

                    Lx = Distance between the Left and Right end of the roof on the Roof BOW [mm]

                            The width of the roof panel is exposed on the surface.

                    Y = Distance front Front Roof Rail to Roof BOW[mm]

                    s = Distance for which Roof BOW bears divided load [mm]

                    Iy = Geometrical moment of inertia of Roof BOW (Y cross-section )[mm4]

                   Rx = Lateral direction curvature radius of roof panel Y cross-section on Roof BOW [mm]

                             Roof panel curvature Radius of the Length Lx in Front view 

                   Ry = Longitudinal Direction curvature radius of the Roof panel X cross-section on Roof BOW [mm]

                            Roof panel X curvature radius of length s in Side view

• Sectional Analysis

BOW RAIL - 1

CENTRE RAIL

BOW RAIL - 2

NOTE: -  

• All the parts are properly designed, followed design considerations and master sections.
• Assembly has created with essential flanges and reinforcements.
• 0.75mm thickness is given to the parts mentioned along with edge fillets above 3mm + thickness of the component.
• All the sufficient images, calculations are provided along with the report, if any issue arises, i had attatched a file along with the assembly file in zip file the below uploading area.
• Proper tree structure is maintained.

CONCLUSION

• From the above table, we can conclude that the position of Front, Rear, Centre and  2 * Bow roofs are placed in good areas as per the results of Heat Distortion and Snow Load analysis.