Roof challenge
OBJECTIVE:-
1. To design the automobile roof based on the given styling surface and to analyze the prepared model to check the manufacturability and the feasibility of the design.
2. To design the section modulus study for the master sections and create for the front roof, rear rail, bow roofs and center roof rail.
3. To create the ditch area and to perfrom the draft analysis.
ROOF:
An automobile roof or car top is the portion of an automobile that sita above the passeger component, protecting the vehicle occupant from sun, wind, rain and other external elements.
The roof itself may be construction of soft or rigid material. soft-tops are made of vinyl, canvas or other textile material hard-top convertibles have roof made from steel, aluminum, plastic or carbon fibre composte your vehicle can also because runined in an accident. through a defect may seen insignificant at first it can lead to serious consequency. whether your was dented due to downfull or roughed up in a collsion, it is urgently necessary to the fi d a replacement for it. the roof panel is attached to the BIW of the car with the help of front and rear roof rail. this attachement is done with the help of sealants bow roofs 1 and 2 are attached depending upon the leght of the roof along with the center roof rail longer the roof more the number of roof rail. other dimension like strenght and material is govrned by the factor like head room. overall s[pace visibility, ergonomics and t5he rule and regularation of the state where it is sold.
DESIGN CONSIDERATIONS
1. Visibility ceriteria
2. Head clearance
3. Heat distortion and snow load ceriteria
4. material thickness
Material properties:
Density : 7890 kg/m3
young's modulus : 210000Mpa
poisson's ration : 0.3
Yield stress : 210 Mpa
Metal Roof Mass : 11.2Kgs
Thickness : 0.75 mm
Joining process : Metal roof with spotweld connections.
ASSEMBLY COMPONENTS OF ROOF:
MASTER SECTION OF FRONT ROOF RAIL
FRONT ROOF RAIL
It is the support that is join with the windshideld glass, body side outer and innear panels it is usually made from body side other scrap and therefore the thickness of the rail is 0.75mm. a draft angle of 3-5 degree is provided for deep drawing operation the visibility ceriteria and head room clearance are taken into consideration for the bottom most flage windshield end and the roof end are spot welded and the other end of the front roof rail is joined with the roof using mastic sealants for increased strength.
BOW ROOF 1:- Bow roof center 1 is an additional stiffening member used in the roof assembly for the localised sternght improvenment and it is join directly to roof itself several spot welding or even with mastic sealent.
BOW ROOF 2 : It is similar to that of bow roof 1 which serves the same purpose as the previous but with a limited extend and hance it is used with a smaller cross.
MASTIC POINTS:
Why automotive uses MASTIC SEALANTS?
Enfineer are constantly faces with the challenes of sealing assembiles against air, dust, noise, and making sure that these assemblies do not squeak and / or rattle.
Sealants are material that are for one time use only. meaning the whole assemble is replace or the particular area that needs to be sealed will not be taken apart and the put back together as part of its requirement.
prevents exssive absorption of adhesive or penetration of the liquid or gaseous substances.
. Reduction of Direct labour costs
. reduction of indirect/inventory management
. Reduction of scrap materials
. material cost reduction
. Ease of accommodation of engineerinf changes
CENTER ROOF RAIL:- Center roof rail or reinforcement center is used as a cross member between left hand and roght hand respectively. in some cases, it is made to join both roof and body side the reinforcement center and bow roof are joined either spot weld or by mastic sealants.
REAR ROOF RAIL:
back door and the rear roof rail got atteched here with the help of masting sealants.
I maintained 0.75 mm thickness for the rear of rail. why because if we use more than 0.75 mm means there is increase in overall weight of the car leads to low performance need more power simply weight of the car increase.
This 0.75 mm is the perfect and standard thickness for the automotive sheet meatal components.
Thickness for automotive sheetmetal component vary from 0.65 mm to 0.75 mm.
It is the support that is joined to the backdoor the bodyside outer and the innear panels inputs from the backdoor design is also taken to accommodate the required clearance and very visibility criteria while designing the rear roof rail. spot welds ar4e applied at the backdoor end of the rail and other end joined with the roof.
I provided some embosses for the extra strenght for the front roof rail. we giving embosses for the strenght to the component.
DITCH AREA:- it is the extended portion of the main roof concealed by other BIW panels and not a stylind surface. headroom clearance, visibility ceriteria clearance for windshield and back door are the some of the factore to be considered while designg the ditch area.
DRAFT ANALYSIS:-
draft analysis is a method of checking the draft angle on various faces of a part with a particular direction.
Draft analysis command enables you to detedt if the pary you drafted will be easuily removed this type of analyis element where the deviation from the draft direction at ant point, corresponding specified values.
HEAT DISTORTION CURVATURE STUDY:
The heat distroption study planes an important role is sheet metal usage heat distrotion temperature is a temperature limit above which the material connat be used for structure application, this study is used to predicty the heat distrotion temperature at where the material starts to softten when exposed to a fixed load at elevated temperature in order to avoid bending or damage on roof, based on heat distortion temperature, this study will predict the bow roof position on the roof to strengthen the roof.
MOMENT OF INERTIA (IY);
FRONT ROOF RAIL:
BOW ROOF 1:
CENTER ROOF RAIL:
BOW ROOF 2:
RAER ROOF RAIL
