Roof Design
AIM :- TO DESIGN A ROOF WITH ROOF OUTER REAR FLANGE , FRONT ROOF RAIL , BOW ROOF RAIL 1 , BOW ROOF RAIL 2 , CENTER ROOF RAIL WITH REINFORNCEMENT RAIL AND REAR ROOF RAIL AS AN ASSEMBLY WITH THE GIVEN DATA AND PROVIDED THICKNESS USING CAD MODELING SOFTWARE SIEMENS NX-CAD .
OBJECTIVES :-
- DESIGNING OF THE FRONT ROOF RAIL, REAR ROOF RAIL, BOW ROOF'S, CENTER ROOF RAIL WITH REINFORCEMENT RAIL USING THE GIVEN STYLING DATA.
- POSITIONING OF BOW ROOF'S AND CENTER ROOF RAILS TO GET THE PROPER CURVATURE.
- CREATE A CURVATURE STUDY ON THE ROOF AND VALIDATE THE DESIGN PHYSIBLE FOR MANUFACTURING USING THE HEAT DISTORTION AND SNOW LOAD CRITERIA .
- PERFORMING THE SECTION MODULUS ON THE SOLID SECTION OF BOW ROOF'S , CENTER ROOF'S , FRONT AND REAR ROOF'S TO CALCULATE THE MINIMUM MOMENT OF INERTIA OF THE ROOF RAIL'S.
- PERFORMING THE DRAFT ANALYSIS ON BOW ROOF'S , CENTER ROOF'S , FRONT AND REAR ROOF'S WITH AN TOOL OPENING ANGLE OF 7 DEGREE'S.
DESCRIPTION :-
AN AUTOMOBILE ROOF OR CAR TOP IS THE PORTION OF AN AUTOMOBILE THAT SITS ABOVE THE PASSENGER COMPARTMENT , PROTECTING THE OCCUPANTS FROM VARIOUS ENVIORNMENTAL CONDITIONS SUCH AS EXTREME HEAT OF THE SUN , WIND ,RAIN ETC.
TYPES OF CAR ROOFS :-
THERE ARE 3 TYPES OF ROOFS COMMONLY INSTALLED ON CARS WHICH ARE SUN ROOF , MOON ROOF , PANORAMIC ROOFS . SUNROOFS ARE ALSO OFTEN CALLED MOON ROOF . ALL THREE ARE DIFFERENT IN TERMS OF USE AND BENIFITS.
SOLID OR HARDTOP :- This is the fixed, solid metal roof that you see on most vehicles, often referred to as a “hardtop,” and it is generally the default roof option. Convertible: Sometimes also referred to as a “cabriolet,” a convertible gives drivers the option of going roofless.
SOFTTOP ROOF :- These vehicles are named “soft-top” because the roof is made up of fabric. The material could be made of nylon or even PVC. One of the major advantages of soft-top compared to hardtop convertibles is that they reduce weight on the vehicle.
THE ROOF IS ALSO A STYLING SURFACE WHICH IS ATTACHED TO THE TOP OF THE BIW THROUGH THE ROOF RAILS USING SPOT WELDING AND MASTIC DATA TO PROVIDE STRENGTH AND STIFFNESS TO THE ROOF.
THE DITCH AREA IS THE EXTENDING PART OF THE ROOF IN LONGITUDINAL DIRECTION OF THE VEHICLE.
THE RAILS AND THE REINFORCEMENTS ARE CONCEALED TO THE DITCH AREA WITH SPOT WELDING.
THE REQUIRED TOOL OPENING ANGLE FOR ROOF DITCH AND OTHER COMPONENTS IS 7 DEGREE SO THAT THE PART WILL BE EASY TO MANUFACTURE .
FACTORS TO BE CONSIDER WHILE CREATING THE DITCH AREA :-
- HEADROOM CLEARENCE
- VISIBILITY CRITERIA
- BACKDOOR ASSEMBLY
- WINDSHIELD ASSEMBLY
APPROACH TO WORK ON THE GIVEN ROOF DESIGN DATA :-
(1). DESIGNING THE ROOF ASSEMBLY USING GIVEN STYLING DATA.
(2). DESIGNING OF ROOF OUTER REAR FLANGE
(3). CREATION OF FRON ROOF RAIL.
(4). CREATION OF BOW ROOF RAIL 1 ALONG WITH SIDE FLANGE.
(5). CREATION OF CENTER ROOF RAIL ALONG WITH SIDE FLANGE.
(6). CREATION OF REINFORCEMENT RAIL.
(7). CREATION OF BOW ROOF RAIL 2 ALONG WITH SIDE FLANGE.
(8). CREATING AND MEASURING ALL THE ARC, CURVES, LENGTH'S REQUIRED FOR CALCULATIONS .
(9). HEAT DISTORTION CALCULATIONS.
(10). SNOW LOAD CRITERIA CALCULATIONS.
(11). DRAFT ANALYSIS ON ROOF OUTER AND ALL THE SUPPORTING ROOF RAILS.
DESIGNING THE ROOF SURFACE USING STYLING PART ( ROOF OUTER REAR FLANGE ) :-
1. USE THE ROOF OUTER SURFACE UNTRIM IT AND THEN TRIM IT WITH THE ROOF OUTER SURFACE TO GET THE PROPER ROOF OUTER SURFACE , THEN TRIM IT FROM THE MIDDLE SECTION USING ZC PLANE.
2 USE BRIDGE CURVE OF 5MM TO AVOID SHARP EDGES ON THE CORNORS OF ROOF STYLING SURFACE
3. FOR CREATING FRONT FLANGE , SIDE FLANGE , REAR FLANGE USE LAW EXTENSION WITH APPROPRIATE ANGLE , VECTOR AND LENGTH.
4. FOR FRONT FLANGE USE LAW EXTENSION OF 15MM LENGTH AND -3 DEGREES ANGLE LAW, THEN LAW EXTENSION OF 21.5 MM LENGTH AND 25 DEGREES OF ANGLE LAW.
5. FOR SIDE FLANGE USE LAW EXTENSION OF 15MM LENGTH AND -10 DEGREES OF ANGLE LAW , THEN LAW EXTENSION OF 20 MM LENGTH AND 25 DEGREES OF ANGLE LAW.
6. FOR REAR FLANGE USE LAW EXTENSION OF 38MM LENGTH AND 25 DEGREES OF ANGLE LAW, THEN LAW EXTENSION OF 45.5 MM LENGTH AND -10 DEGREES OF ANGLE LAW, THEN LAW ECTENSION OF 50 MM LENGTH AND 0 DEGREES OF ANGLE LAW , THEN LAW EXTENSION OF 25 MM LENGTH AND 30 DEGREES OF ANGLE LAW , THEN LAW EXTENSION OF 25 MM LENGTH AND 30 DEGREES OF ANGLE LAW WITH APPROPRIATE VECTOR DIRECTION.
7. THEN USE STUDIO SURFACE AND BRIDGE CURVE TO CLOSE THE SIDE CORNER OF THE SIDE , REAR , FRONT FLANGES AND THE ROOF OUTER SURFACE.
8. PROVIDE FACE BLEND OF 2.2 MM TO THE ROOF OUTER FRONT AND SIDE FLANGE.
9. FOR REAR FLANGE PROVIDE FACE BLEND OF 2.2,10,5,5,2.2 MM RESPECTIVELY.
10. EXTEND THE MIDDLE CROSS SECTION OF ROOF OUTER AND TRIM THE SURFACE WITH ZC PLANE AFTER IT USE MIRROE GEOMETERY OPTION TO MIRROR THE ROOF OUTER SURFACE.
11. SEW BOTH THE SURFACES AND USE THICKEN COMMAND TO CONVERT THE ROOF OUTER SURFACE INTO SOLID BODY PROVIDING THE THICKNESS OF 0.75 MM.
DISIGNING OF FRONT ROOF RAIL :-
1. OFFSET THE STYLING SURFACE 32 MM DOWNWARDS ACCORDING TO THE MASTER SECTION PROVIDED.
2. USE LAW EXTENSION OF 20 MM LENGTH AND 25 DEGREES OF OFFSETED SURFACE ACCORDING TO THE PROVIDED MASTER SECTION.
3. OFFEST THE FLANGE OF ROOF.
4. TRIM THE SURFACE TO 80 MM.
5. OFFSET THE ROOF UPPER SURFACE BY (0.75+0.75+5) AND (3+0.75+0.75) THEN CUT IT BY 5MM AND 10MM RESPECTIVELY USING CURVE IN FACE AND TRIM SHEET OPTION.
6. JOIN THE CREATED SURFACES USING LAW EXTENSION AND STUDIO SURFACE.
7. USE MAKE CORNOR IN TRIM AND EXTEND OPTION WHERE LAW EXTENSION IS PROVIDED TO GET THE DESIRED SURFACES.
8. PROVIDE ALL THE NECESSARY FACE BLENDS TO THE FRONT ROOF RAIL ACCORDING TO THE MASTERSECTION PROVIDED.
9. USE EXTEND SHEET IN THE MIDDLE CROSS-SECTION OF THE ROOF RAIL, THEN TRIM IT WITH THE ZC PLANE .
10. MIRROR THE FRONT ROOF RAIL USING MIRROR GEOMETERY OPTION WITH ZC PLANE .
11. SEW BOTH THE SURFACES AND USE THICKEN COMMAND TO CONVERT SURFACES TO SOLID BODY PROVIDING THICKNESS OF 0.75MM.
DISIGNING OF BOW ROOF RAIL 1 :-
BOW ROOF ARE BASICALLY DESIGNED TO PROVIDE STRENGTH TO THE ROOF AND ARE CONCEALED WITH THE ROOF OUTER SURFACE USING SPOT WELDING ON THE SIDE FLANGES TO THE SIDE DITCH AREA OF ROOF OUTER AND WITH THE HELP OF MASTICS IN BETWEEN THE BOW AND ROOF OUTER.
1. OFFSET THE ROOF OUTER SURFACE WITH (0.75MM+5MM+0.75MM) ACCORDING TO THE MASTERSECTION PROVIDED TO GET THE FIRST FLANGE OF BOW ROOF.
2. TRIM THE OFFSET SURFACE CONSIDERING THE OVERALL BOW ROOF LENGTH OF 65 TO 75 MM, HERE I HAD USED 70MM.
3. CREATE A PLANE ON CURVE ON THE MIDDLE CROSS-SECTION OF THE ROOF OUTER , TAKE INTERSECTION CURVE , THEN OFFSET CURVE IN FACE AT A DISTANCE OF 16 MM AND 70 MM FROM INTERSECTION CURVE , THEN TRIM THE OFFSETED SURFACE.
4. FOLLOW SAME PROCEDURE FOR OTHER 3 FLANGES OF BOW ROOF WHERE MIDDLE SURFACE IS OFFSETED AT 12.25MM AND BOTH THE DOWNWARDS SURFACES ARE OFFSETED AT 19.25 MM FROM THE ROOF OUTER SURFACE.
5. USE LAW EXTENSION OF DESIRED LENGTH AND DRAFT ANGLE TO JOIN THE ALL 5 FACES .
6. USE MAKE CORNOR IN TRIM AND EXTEND OPTION WHERE LAW EXTENSION IS PROVIDED TO GET THE DESIRED SURFACES.
7. PROVIDE ALL THE NECESSARY FACE BLENDS TO THE BOW ROOF RAIL ACCORDING TO THE MASTERSECTION PROVIDED.
8. EXTRACT THE SIDE FLANGE OF THE ROOF OUTER SURFACE THEN OFFSET THE EXTRACTED SURFACE WITH OFFSET OF 1.5MM THEN TRIM IT WITH THE DATAM PLANES BY CREATING THE PLANES ON OFFSETED SURFACE USING PLANE ON CURVE OPTION.
9. USE BRIDGE CURVE OPTION TO GET THE SMOOTH PROFILE JOINING THE BOW ROOF AND SIDE FLANGE.
10. CREATE ALL THE JOINING SURFACES USING SWEPT , THROUGH CURVES, STUDIO SURFACES.
11. SEW SIDE FLANGE OF THE BOW ROOF WITH THE BOW ROOF RAIL.
12. CREATE A SKETCH ON YZ PLANE TO CREATE MASTIC DATA POINTS, PROJECT THE SKETCH ON BOW ROOF AND THEN TRIM THE PROJECTED SKETCH WITH THE BOW ROOF RAIL
13. USE EXTEND SHEET IN THE MIDDLE CROSECTION OF THE ROOF RAIL, THEN TRIM IT WITH THE ZC PLANE .
14. MIRROR THE BOW ROOF RAIL USING MIRROR GEOMETERY OPTION WITH ZC PLANE .
15. SEW BOTH THE SURFACES AND USE THICKEN COMMAND TO CONVERT SURFACES TO SOLID BODY PROVIDING THICKNESS OF 0.75MM.
DESIGNING OF CENTER ROOF RAIL :-
1. CREATE A DATUM PLANE ON CURVE IN THE MIDDLE CROSS-SECTION OF THE ROOF TAKING PARCENTAGE ARC LENGTH AROUND 50 , TAKE INTERSECTION USING PLANE.
2. OFFSET THE ROOF OUTER SURFACE WITH (0.75MM+5MM+0.75MM+0.75) ACCORDING TO THE MASTERSECTION PROVIDED TO GET THE FIRST FLANGE OF BOW ROOF.
3. TRIM THE OFFSET SURFACE CONSIDERING THE OVERALL BOW ROOF LENGTH OF 80 TO 90 MM, HERE I HAD USED 90MM.
4. THEN OFFSET CURVE IN FACE AT A DISTANCE OF 20.5MM AND 90 MM USING INTERSECTION CURVE , THEN TRIM THE OFFSETED SURFACE.
5. FOLLOW SAME PROCEDURE FOR OTHER 3 FLANGES OF CENTER ROOF ROOF WHERE MIDDLE SURFACE IS OFFSETED AT 13 MM AND BOTH THE DOWNWARDS SURFACES ARE OFFSETED AT 18 MM FROM THE ROOF OUTER SURFACE.
6. USE LAW EXTENSION OF DESIRED LENGTH AND DRAFT ANGLE TO JOIN THE ALL 5 FACES .
7. USE MAKE CORNOR IN TRIM AND EXTEND OPTION WHERE LAW EXTENSION IS PROVIDED TO GET THE DESIRED SURFACES.
8. PROVIDE ALL THE NECESSARY FACE BLENDS TO THE CENTER ROOF RAIL ACCORDING TO THE MASTERSECTION PROVIDED.
9. EXTRACT THE SIDE FLANGE OF THE ROOF OUTER SURFACE THEN OFFSET THE EXTRACTED SURFACE WITH OFFSET OF 1.5MM THEN TRIM IT WITH THE DATAM PLANES BY CREATING THE PLANES ON OFFSETED SURFACE USING PLANE ON CURVE OPTION.
10. USE BRIDGE CURVE OPTION TO GET THE SMOOTH PROFILE JOINING THE BOW ROOF AND SIDE FLANGE.
11. CREATE ALL THE JOINING SURFACES USING SWEPT , THROUGH CURVES, STUDIO SURFACES.
12. SEW SIDE FLANGE OF THE BOW ROOF WITH THE BOW ROOF RAIL.
13. CREATE A SKETCH ON YZ PLANE TO CREATE MASTIC DATA POINTS, PROGECT THE SKETCH ON BOW ROOF AND THEN TRIM THE PROJECTED SKETCH WITH THE BOW ROOF RAIL
14. USE EXTEND SHEET IN THE MIDDLE CROSECTION OF THE ROOF RAIL, THEN TRIM IT WITH THE ZC PLANE .
15. MIRROR THE BOW ROOF RAIL USING MIRROR GEOMETERY OPTION WITH ZC PLANE .
16. SEW BOTH THE SURFACES AND USE THICKEN COMMAND TO CONVERT SURFACES TO SOLID BODY PROVIDING THICKNESS OF 0.75MM.
DESIGNING REINFORCEMENT ROOF RAIL :-
FOLLOW THE SAME PROCEDURE USED IN THE CREATION OF CENTER ROOF RAIL TAKING APPROPRIATE LENGTH , OFFSET , VECTOR, ANGLE ETC , REINFORCEMENT RAIL DOSENT CONSIST OF SIDE FLANGES.
DESIGNING BOW ROOF RAIL 2 :-
CREATE A DATUM PLANE ON CURVE IN THE MIDDLE CROSS-SECTION OF THE ROOF TAKING PARCENTAGE ARC LENGTH AROUND 75 , TAKE INTERSECTION AND FOLLW THE SAME PROCEDURE USED IND THE DESIGNING OF BOW ROOF RAIL 1.
DESIGNING REAR ROOF RAIL :-
1. TAKE OFFSET OF REAR FLANGE OF ROOF OUTER SURFACE AT A DISTANCE OF 10.7 MM AS SHOWN IN THE MASTER SECTION .
2. THEN , FOLLOW THE SAME PROCEDURE USED IN THE DISIGNING OF FRON ROOF RAIL FOLLOWING THE PROVIDED MASTER-SECTION.
CURVATURE STUDY ON THE ROOF :-
AFTER DESIGNING THE ROOF AND ALL OTHER ROOF RAILS THE DESIGN SHOULD PASS THE MANUFACTURING PHYSIBILITY AND THE POSITIONING OF THE BOW ROOFS AND THE CENTER ROOF RAILS SHOULD BE DONE IN PROPER WAY CONSIDERING ALL THE DESIGNING STANDARDS TO GET PROPER STRENGTH AND STIFFNESS TO THE COMPONENT ALSO CONSIDERING VARIOUS ENVIORNMENTAL CONDITIONS WE PERFORM SOME TESTS FOR MANUFACTURING OF SAFER ROOF'S ARE :-
1. HEAT DISTORTION.
2. SNOW LOAD CRITERIA.
3. ROLL OVER.
HEAT DISTORTION CRITERIA :- HEAT DISTORTION IS BASICALLY USED TO CHECK THE STRENGTH OF THE ROOF. HEAT DISTORTION TESTS DEPLITS THE DEFORMATION OF THE ROOF SHEET METAL BY STUDYING THE CURVATURE OF ROOF BY USING ROOF RAILS AND SPECIFIC PIONTS UNDER SPECIFIC LOAD AND VARIOUS ENVIORNMENTAL CONDITIONS.
1. TO CALCULATE THE HEAT DISTORTION CRITERIA BY THE BOW ROOF POSITION FORMULA.
2. CREATE A SKETCH ON ZC PLANE , DRAW A LINE ON THE CENTER OF THE ROOF ON OY AXIS.
3. THEN DRAW AN OFFSET LINE BELOW THE CENTER LINE AT DISTANCE OF 300MM, WHICH WILL BE OUR 3-Y.
4. THEN THE 3-Y LINE SHOULD BE OFFSETED ABOVE AND BELOW AT A DISTANCE OF 100MM.
5.PROJECT THE SIDE CORNER EDGES OF THE FRONT AND BOW 1 ROOF RAILS, USING THE INTERSECTION POINTS OF BOTH THE PROJECTED CURVES AT 0-Y CREATE MID-POINT USING BOTH THE INTERSECTION POINTS.
6.CREATE A VERTICAL LINE USING THE MID-POINT , THEN OFFSET THE SAME MID-POINT LINE TO THE LEFT AND RIGHT AT A DISTANCE OF 100 MM.
7. AFTER THIS CREATE THE INTERSECTION POINTS ON THE LINES INTERSECTING EACHOTHER.
8. AFTER THIS , PROJECT THE INTERSECTION POINTS TO THE ROOF OUTER SURFACE.
9. THEN CREATE THREE PONT ARC USING THE INTERSECTION POINTS TO GET THE Rx and Ry CURVATURE OF THE GIVEN STYLING SURFACE, THEN MEASURE THE RADIUS OF CURVATURE USING THE ARC'S.
10. FOLLOW THE SAME PROCEDURE TO CALCULATE THE VALUE OF Rx AND Ry BETWEEN ALL THE ROOF RAIL'S.
FORMULA :-
W = [1.73 x 10^(-3) x L] + [1.85 x 10^(-8) x (R^2)/t] + [ 1.10x10^(-3) x l] - 2.68
JUDGEMENT CONDITION :- OK< 2.7> 3.1
WHERE,
L = ROOF LENGTH IN X-DIRECTION[mm](ROOF DIMENSION IN 0-Y)
R = ROOF CURVATURE
R = 2(Rx*Ry)/(Rx+Ry)
Rx = X CURVATURE
Ry = Y CURVATURE
t = ROOF PLATE THICKNESS [mm]
l = BOW ROOF SPAN [mm]
CALCULATIONS :-
W = [1.73 x 10^(-3) x L] + [1.85 x 10^(-8) x (R^2)/t] + [ 1.10x10^(-3) x l] - 2.68
| BOW POSITION | Rx | Ry | R | I | L | t | W | OK/NG |
| FR and 1st | 5741.17 | 2443.68 | 3428.18 | 358.06 | 2029.13 | 0.75 | 1.51 | OK |
| 1st and CTR | 4903.19 | 6475.16 | 5580.58 | 537.57 | 2029.13 | 0.75 | 2.18 | OK |
| CTR and 2nd | 3913.21 | 10911.52 | 5760.51 | 320.83 | 2029.13 | 0.75 | 2.00 | OK |
| 2nd and RR | 3298.33 | 14468.92 | 5372.04 | 359.28 | 2029.13 | 0.75 | 1.93 | OK |
SNOW LOAD CRITERIA :- SNOW LOAD IS USED TO VARIFY THAT ROOF ASSEMBLY EXHIBITED NO PERMANENT DEFLECTION DUE TO DISTRIBUTED LOAD REPRESENTING SNOW LOAD.
1. TO CALCULATE THE SNOW- LOAD CONDITION , WE HAVE SNOW-LOAD FORMULA.
2. CREATE A SKETCH ON ZC PLANE , THEN CREATE A CENTER LINE 0-Y.
3. THEN CREATE OFFSET OF 0-Y LINE 100MM ABOVE AND 100MM BELOW THE CENTER LINE.
4. PROJECT THE CORNOR EDGES OF THE FRONT AND BOW 1 ROOF RAILS, AFTER THIS TAKE THE INTERSECTION POINTS OF THE PROJECTED CURVES AND CREATE MID POINT ON THE 0-Y LINE USING THE INTERSECTION POINTS.
5. CREATE A VERTICAL LINE USING THE MID POINT AND THEN OFFSET THE VERTICAL LINE 100 MM TO THE LEFT AND 100 MM TO THE RIGHT.
6. CREATE THE POINT ON THE LINES INTERSECTING EACHOTHER.
7. AFTER THIS , PROJECT THE INTERSECTION POINTS TO THE ROOF OUTER SURFACE.
8. THEN CREATE THREE PONT ARC USING THE INTERSECTION POINTS TO GET THE Rx and Ry CURVATURE OF THE GIVEN STYLING SURFACE, THEN MEASURE THE RADIUS OF CURVATURE USING THE ARC'S, THE ARC ON THE 0-Y AXIS IS OUR Ry AND THE PERPENDICULAR ARC WILL BE Rx.
9. FOLLOW THE SAME PROCEDURE TO CALCULATE THE VALUE OF Rx AND Ry BETWEEN ALL THE ROOF RAIL'S.
Measure the Radius of the arcs, the arc on the OY axis going to be our Ry and the perpendicular arcs will be Rx
Qr = [Iy x t2] / [α x s x [(Rx + Ry)/2]2 x 10-8]
WHERE,
α = My x Lx2 x 10-12 , My = Y(Ly-Y)
JUDGEMENT CONDITION = Qr ≥ 3.1
250 ≤ s ≤ 380
t = ROOF PLATE THICKNESS [mm]
Ly = DISTANCE BETWEEN THE FRONT AND REAR ROOF RAILS ON THE VEHICLE ALONG WITH 0Y[mm]
LENGTH OF ROOF PANELWITH 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]
WIDTH OF THE ROOF PANEL EXPOSED ON THE SURFACE.
Y = DISTANCW front FRONT ROOF RAIL TO ROOF BOW[mm]
s = DISTANCE FOR WICH ROOF BOW BEARS DIVIDED LOAD[mm]
s = L1/2 + L2/2
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 = LONGITUDIONAL DIRECTION CURVATURE RADIUS OF THE ROOF PANEL X CROSS-SECTION ON ROOF BOW [mm]
ROOF PANEL X CURVATURE RATIUS OF LENGTH s IN SIDE VIEW.
MOMENT OF INERTIA :-
FRONT ROOF RAIL :-
BOW ROOF RAIL 1 :-
CENTER ROOF RAIL :-
BOW ROOF RAIL :-
REAR ROOF RAIL :-
CALCULATIONS :-
Qr = [Iy x t2] / [α x s x [(Rx + Ry)/2]2 x 10-8]
| BOW POSITION | Iy | α | Lx | Ly | Y | S | Rx | Ry | t | Qr | DETERMINATION |
| FR and 1st | 2017.31 | 0.87 | 1140.08 | 1949.92 | 450.58 | 533.65 | 4594.02 | 2512.14 | 0.75 | 19.18 | OK |
| 1st and CTR | 1438.78 | 1.10 | 1084.58 | 1949.92 | 1067.03 | 509.75 | 3779.97 | 6397.78 | 0.75 | 5.53 | OK |
| CTR and 2nd | 1996.84 | 0.78 | 1056.94 | 1949.92 | 1470.10 | 441.3 | 4303.13 | 11499.38 | 0.75 | 3.20 | OK |
DRAFT ANALYSIS :-
[A] ROOF :-
[B] FRONT ROOF RAIL :-
[C] BOW ROOF RAIL 1 :-
[D] CENTER ROOF RAIL , REINFORCEMENT RAIL :-
[E] BOW ROOF RAIL 2 :-
[F] REAR ROOF RAIL :-
FINAL ROOF DESIGN IN VARIOUS ORIENTATIONS :-
[A] FRONT VIEW :- [B] SIDE VIEW :-
[C] ISOMETRIC VIEW :- [D] TOP VIEW :-
MANUFACTURING TECHNIQUES USED FOR THE PRODUCTION OF ROOF'S :-
The manufacturing process of the automobile roof component comprises the following steps respectively consists of an outer plate processing process, a strip-shaped assembly and annular assembly processing process and an automobile roof side beam processing process, and finally, an automobile roof combining process.
The car roof is produce through the sheel metal forming , stamping and drawing processes. In sheet metal forming, the final shape of a part is made from a flat metal sheet. The desired shape is achieved through plastic deformation, without undergoing any machining like milling. In most cases, a certain amount of elastic deformation leads to springback which occurs after forming is complete.
MANUFACTURING OF ROOF AND ROOF RAILS USING DIFFERENT MATERIALS :-
CONCLUSION :-
- I GOT KNOWLEDGE PN HOW TO DESIGN ROOF , FRONT ROOF RAIL , REAR ROOF RAIL , BOW ROOF'S , CENTER ROOF RAIL , REINFORCEMENT ROOF CENTER BY FOLLOWING THE MASTER SECTION WITH THE DESIGN PARAMETERS FOR THE GIVEN CLASS A SURFACE.
- THUS FROM THE CALCULATIONS DONE BY ME PASSES THE HEAT DISTORTION AND SNOW LOAD CRITERIA ON THE GIVEN SURFACE AND THE POSITIONING OF BOW ROOF'S WERE DETERMINED.