- Open Access
- Authors : Vivekanandhan M, Raguram R S, Poovarasan K, Kondusamy V, Vignesh G, Vyshaak R B
- Paper ID : IJERTV10IS030027
- Volume & Issue : Volume 10, Issue 03 (March 2021)
- Published (First Online): 05-01-2019
- ISSN (Online) : 2278-0181
- Publisher Name : IJERT
- License: This work is licensed under a Creative Commons Attribution 4.0 International License
Design and Analysis of SAE Supra Chassis
Kondusamy V1, Poovarasan K2, Raguram R S3 , Vivekanandhan M4, Vyshaak R B5, Vignesh G6
1 Assistant Professor, Department of Automobile Engineering, Karpagam college of Engineering, Coimbatore, Tamilnadu.
2,3,4,5,6 Students, Department of Automobile Engineering, Karpagam college of Engineering, Coimbatore, Tamilnadu.
- INTRODUCTIONThe chassis shape must competently assist the burden of the car components and transmit loads that result from longitudinal, lateral and vertical accelerations which might be experienced in a racing environment without failure. This paper probes the diverse components of chassis design. Some important questions addressed are: What is the high-quality manner to transfer the hundreds via the structure? How stiff ought to the body be? How a chassis has impact on exceptional race situation? What is the effect of pipe diameter and pass phase at the stiffness of the chassis? What need to be the appropriate component of protection whilst designing a body?Supra SAE India is a countrywide degree pupil opposition, organized with the aid of Society of Automobile Engineers India, wherein students are asked to layout, manufacture and run a prototype of open wheel racing automobile. This competition is performed annually in India and approximately a hundred and eighty faculties take part each year from throughout India.Following the technical inspection are the sub events which include the static occasions like tilt test, brake check, price report presentation, engineering layout report and business presentation, dynamic events like acceleration check, skid pad, autocross and persistence test. In this excessive octane state of affairs, an automobile is expected to carry out high on acceleration, dealing with, braking, aesthetics, ergonomics, fabrication and renovation with least funding in fabrication without compromising on protection of the driver. The motive of the thesis is to design and manufacture tubular space frame chassis that should be robust enough to take in the power while the front, lower back, side, torsional loads are applied.
For the cause of the application on a high overall performance racing automobile, it has to meet the following criteria:
- Minimize the weight to stiffness ratio
- Maintain Low Center of Gravity
- Reasonable material and manufacturing costs
- Create a solid base chassis to evolve on for years to come
- Aesthetically pleasing design
The number one objective of the chassis is to offer a shape that connects the front and rear suspension without immoderate deflection. When considering a race car chassis, a frame this is effortlessly twisted will result in massive coping with troubles. The lateral loading on a vehicle is taken up in places; the frame and the suspension.
Fig 1.1 SAE Supra Chassis
The suspension may be adjusted, the frame cannot. So to get required dealing with, the frame have to be stiffer to compensate lateral loading on the auto. On the whole, a frame that is capable of preserve torsional loads resulting from inertial accelerations of components experienced in the course of cornering or from carried out hundreds acting on one or opposite corners of the car will almost continually be sufficiently robust.
The integrity of a layout may be ensured only after a scientific material selection method. Since the chassis needs to be designed for harsh riding situations, the choice of material turns into a critical part of design method.
The mechanical Structural Performance Analysis of SAE Supra Chassis 241 houses such elasticity modulus E, the shear modulus G, density and yield stress fy are important from design point of view. For selection of suitable fabric for chassis, prepare a selection matrix of critical aspect which can have an effect on the overall performance of the autos mechanical houses, fee and availability.
The chassis undergoes various kinds of forces at some stage in locomotion, it has to live intact without yielding, and it must be stiff to absorb vibrations, additionally it need to withstand excessive temperatures. The fabric assets of the chassis are an important criterion at the same time as designing and manufacturing the automobile. A tubular space body chassis became chosen over a monocoque chassis notwithstanding being heavier because, its manufacturing is cost effective requires simple tools and damages to the chassis may be effortlessly rectified. The very typically used substances for making the distance body chassis are Chromium Molybdenum metal (Chromoly) and SAE-AISI 1018.
Both those materials had been analyzed for specific parameters and subsequently decided on to apply
Chromoly metal 4130 for making the tubular area body chassis due to several reasons. SAE 1018 grade steel is better in phrases of Thermal homes however weaker than Chromoly in terms of power. But the primary precedence of layout is protection for the driver therefore the fabric with better stiffness and energy changed into chosen.
The material must no longer motive any failure even underneath extreme situations of using as described in the rule e book. Chromoly metal 4130 exhibits better structural property than SAE 1018 Grade steel for this reason the former turned into taken into consideration as the primary cloth for building a tubular area body chassis. Even though the cost of Chromoly is marginally higher than that of SAE 1018 grade steel, the protection of the driving force remains the maximum priority for the team. Change in Youngs Modulus with respect to Compressive Stress
The cloth reveals a three hundred% boom in Youngs modulus (80 MPa), considerable transition from a bendy low modulus as-organized figure. We count on latent heat of solidification to be released into the matrix, but, estimated dissipation time primarily based on Fouriers regulation shows that the change in temperature would be in large part unnoticeable. In contrast, the EGaIn sample fractured upon compression whilst stable FM composites display a statistically insignificant growth in stiffness.
To affirm differences in mechanical houses of the compressed samples, we issue the substances to excessive stresses, expecting that shape alternate and network formation will differentiate compressed ST3R composite from stable FM samples. Besides the larger (300%) initial stiffness for ST3R, we found an asymptotic mechanical response previous to yielding, similar to plastic deformation in metals. The networks spoil as pressure is accelerated, main to the knocking down of the strain pressure curve at better strains.
This phenomenon is similarly investigated by varying the volume of filler. When f = 30%, the pre- compressed ST3R and strong FM samples gave similar modulus (1215 MPa). At f=50%, but, a dramatic exchange in modulus is located in the ST3R. This is consistent with the formation of networks whereby a minimum filler quantity is required.
MATERIAL PROPERTY AISI 1018 AISI 4130 Brinell hardness 130-140 200-300 Tensile strength 430-480 (MPa) 530-1040 (MPa) Yield strength 240-400 (MPa) 440-980 (MPa) Shear strength 280-300 (MPa) 340-640 (MPa) Thermal conductivity 52 (W/m-K) 43 (W/m-K) Thermal shock resistance 14-15 (points) 16-31 (poits) Chromium content 0 % 0.8-1.1 %
Thus the material AISI 4130 proves to be most desirable even with the higher cost for a greater safety.
Fig 1.2 Changes in Compressive Stress NORMALIZED COMPLEX STIFFNESS
The alternate in elasticity ought to appear as an asymmetry inside the distribution of complicated stiness leading to a unique trend in skewness for the ST3R composite under dynamic stress compared to static (nonresponsive) analogous composites (e.g. EGaIn, strong FM or glycerol). To verify this inference, we achieved dynamic tensile stress on skinny rectangular samples at 1 Hz, with growing amplitudes from 515% stress. As anticipated, ST3R composite suggests a boom in complex stiffness as strain is expanded, assisting the notion of a strain hardening cloth.
We infer that the rise in complicated stiffness is a result of partial solidification of the below cooled liquid steel, triggered by way of deformation of the composite. In evaluation, EGaIn fillers show a small initial upward thrust in normalized complicated stiffness before a decrease as pressure is expanded. Additional manage experiments of solid FM particles, glycerol droplets, and PDMS (matrix) in addition show a decrease in stiffness as stress is expanded, highlighting the unique behavior of the ST3R.
We also observed a shift in skewness of the distribution of complicated stiffness, whereby effective values represent bias within the mass of the distribution toward decrease stiffness and terrible values point towards better stiffness. It is consequently glaring that only the ST3R composite displayed a shift towards higher complex stiffness. Although stiffness is enhanced after mechanical loading, the boom is at the order of 10%.
Fig 1.3 Vehicle Loading
Frame is described as a fabricated structural meeting that supports all purposeful car structures. This meeting can be a single welded structure, multiple welded structures or an aggregate of composite and welded systems. Depending upon utility of loads and their path, chassis is deformed in respective manner proven beneath.
- Longitudinal Torsion – Created specially by a cornering automobile or bumps in the racetrack. It is the chassis capacity to withstand deformation below this load that defines torsional stiffness.
- Vertical Bending – Vertical bending is created by means of the load of the power and automobiles components, those forces may be boosted through vertical acceleration produced.
- Horizontal Bending – This deformation mode is as a result of the centrifugal forces created with the aid of the cornering of the car.
- Horizontal Lozenging – Occurs whilst the automobile deforms into a parallelogram-like shape, that is caused by the choppy or opposing application of pressure at the wheels on opposite facets of the auto.
EFFECT OF CHASSIS ON DIFFERENT RACE CONDITION
The SAE Supra competition is scored based on two areas, static and dynamic testing, with both having diverse sub-categories. The dynamic section includes 4 occasions; acceleration, skid pad, autocross and staying power. Each of those events needs extraordinary overall performance from the chassis. It is a balancing act to reap foremost overall performance from the vehicle.
Acceleration: This event surely needs a vehicle that can reach excessive speeds quick, hence looking at Newtons 2d law of movement F = ma; accordingly, low mass of chassis will deliver higher acceleration.
Skid pad: This event is a degree of the cars cornering potential around a flat nook. To achieve this, the chassis is required to have an excessive cost of torsional stiffness that is properly balanced all through the chassis.
Autocross: The Autocross event is a standard race track comprising of a straight, regular turns and some different varieties of turns. Cars run at the tune with the average speed among 4048 km/h. This occasion is designed to measure the automobiles favored overall performance effects of dealing with, acceleration and breaking. Thus higher torsional stress of the chassis will yield higher managing.
Endurance: The very last event is the measure of the automobiles reliability, patience and gas economic system. The fuel economic system but will be motivated via the cars chassis, as any superfluous weight will gradual the auto down consequently lowering financial system.
Lateral Load Transfer: When cornering in a steady flip, load is transferred from the internal pairs of the wheels to the outside pair because of centrifugal pressure. This load switch is called lateral load transfer.
Lateral Load Transfer (Lb.) = (Lateral Acceleration
* Center of Gravity * Weight) / Track Width
= (1.5 * 10 * 705.479) / 48
Lb. = 220.462 lbs. = 99.99 kg Force = 99.99 * 9.8 = 979.902 N
Lateral bending is because of the weight switch while cornering that is same to centrifugal pressure and as a result the pressure of 4774. Three N is acted on the side effect member in cockpit, consequently the equal stress is calculated (246 MPa) that is well beneath permissible limit.
Thus fabric will no longer begin to yield all through lateral bending. Longitudinal Load Transfer: Such load switch occurs in a longitudinal plane underneath linear acceleration or deceleration
Longitudinal Load Transfer (Lb.) = (Acceleration * Center of Gravity * Weight) / Track Width
= (1.5 * 10 * 731.667) / 68
Lb. = 161.397 lbs. = 73.209 kg Force = 73.209 * 9.8 = 717.448 N
ACCELERATION AND BRAKE
Test Due to inertia effect, acceleration forces generally tend to act in opposite course to the motion of body. The mass of driver is assumed 70 kg and power train
50 kg and acceleration of engine is three.7 m/s2. As calculated above, longitudinal pressure is implemented on the main hoop; and simultaneous static load because of force and drive teach is acted downward in cockpit region. Equivalent pressure is calculated for this dynamic take a look at which comes as 221 MPa. This is much less than the permissible stress 435 MPa, as a consequence chassis is secure.
Type of impact forces Boundary conditions Force that chassis can withstand after the impact Von mises stress (MPa) FOS Front impact Clamping all suspension pickup points and applying force on front bulk head 9G 261 1.76 Side impact Clamping all suspension pickup points and applying force on side impact member 5G 114 4.03
The characteristic of the frame is to provide the car electricity, structural integrity and to protect the driving force (in case of serious impacts and rollover) and help the front and rear suspension structures, engine, drive educate, steerage system and other structures in the vehicle. It has to be of good enough strength to guard the motive force in case of a coincidence.
SELECTION OF THEORY OF FAILURE
Since all of the checks are completed underneath static structural, the go phase of the issue is thought to be uniform during, but in exercise due to some irregularities, fluctuating load can lead to fatigue failure. These
fluctuating masses are very difficult to calculate and so it is usually desired to have a better issue of safety. It is visible that Distortion Energy Theory (Huber Von Mises and Henckys Theory) predicts yielding with unique accuracy in all four quadrants. Moreover, Distortion Energy Theory is used for ductile materials, while the element of safety is to be held in close limits and the cause of failure of the element is being investigated. This concept predicts failure most correctly. Thus, some of the 3 theories, i.e. Max. Principle Stress Theor, Max. Shear Stress Theory and Distortion Energy Theory, Distortion Energy Theory was selected for designing the chassis.
K – Torsional Stiffness T – Torque
– Angular deformation F – Shear Force
Applied moment (Nm) Deflection (m/deg) Stiffness (Nm/deg) 2.4 mm wall thickness 450 0.10368 480 3.4 mm wall thickness 450 0.034 1470 Applied moment (Nm) Deflection (m/deg) Stiffness (Nm/deg) 2.4 mm wall thickness 450 0.10368 480 3.4 mm wall thickness 450 0.034 1470
y1, y2 – Translational displacement
It is the torsional reaction of a structure to an applied torque loading. An exceptional feasible chassis might be one that has high stiffness; with low weight and fee. If there is enormous twisting, the chassis will vibrate, complicating the machine of the automobile and sacrificing the coping with overall performance. It is proper to layout a chassis with maximum torsional stress. This allows the suspension to do their job efficaciously. In order to design an automobile of most torsional stiffness, the premise or generalized equation for torsion must be tested. Figure beneath is a primary shaft confined at one end and an applied torque T at the opposite, with denoting the ensuing twist of the shaft.
Fig 1.4 Torsional Rigidity T = JG / l
This equation can then be rearranged to express torsional stiffness,
T / = JG / l
This expression presentation that torsional stiffness in proportion to each the polar moment inertia and fabric shear modulus, while being inversely proportional to the period.
The torsional stress can be calculated via locating the torque implemented to the frame and dividing by using the angular deflection.
K = R /
K = (F * L) / tan-1 ((y1 +y2) / 2L)
Force applied 1130 N
y1 = y2 1.68 mm = 0.00168 mm L 0.20
K = (1130 * 2) / tan-1 ((0.00168 + 0.00168) / (2 * 0.20))
K = 482 Nm / deg
Deakin et al. Concluded that a Formula SAE racer, which has a total suspension roll stiffness of 5001500 Nm/deg, requires chassis stiffness among three hundred and one thousand Nm/deg to permit the dealing with to be tuned.
EFFECT OF WALL
Thickness on Torsional Stiffness from the given table, it can be inferred that the thickness of the frame has the maximum impact on the torsional stiffness. The torsional stiffness increases three instances with 1 mm boom in frame thickness. Thus, it will increase stiffness notably and not using a great growth within the weight of the chassis and growing the stiffness to weight ratio of the chassis improving the coping with of the auto.
- LITERATURE REVIEW
- SHUBHAM THOSAR, ANTRIKSH MUTHA andS.A. DHARURKAR discussed in detail in Innovative Design and Development Practices in Aerospace and Automotive Engineering, Lecture Notes in Mechanical Engineering DOI 10.1007/978-981-10-1771-1_27 about the Structural Performance Analysis of SAE Supra Chassis.
- ABHIJEET DAS discussed in detail inInternational Journal of Science and Research (IJSR) ISSN (Online): 2319-7064 Volume 4 Issue 4, April 2015 about the Design of Student Formula Race Car Chassis
- SWATI UPADHYAY, GANESH BADIGERdiscussed in detail in International Research Journal of Engineering and Technology (IRJET) Volume: 07 Issue: 05 May 2020 about the Design and Analysis of Supra Chassis
- PROF. DHAWARE P.A., MISTRY P.T., JOSHIK.S., KARDILE O.B., KALE G.R discussed in detail in IOSR Journal of Engineering (IOSR JEN) ISSN (e): 2250-3021, ISSN (p): 2278-8719,Special Issue June-2019, PP 81-85 about Design and Analysis of Supra CarSHUBHANANDAN DUBEY, RAHUL
SHUBHANANDAN DUBEY, RAHUL
JAISWAL, RAUNAK MISHRA discussed in detail in International Journal of Recent Trends in Engineering & Research (IJRTER) Volume 03, Issue 03; March – 2017 [ISSN: 2455-1457] about Design of Chassis of Student Formula Race Car
- AVINASH BARVE1, SANKET LAKHEdiscussed in detail in International Journal of Science and Research (IJSR) ISSN (Online): 2319-7064 Volume 7 Issue 6, June 2018 about Detailed Design Calculation & Analysis of Student Formula 3 Race Car
- PRASHANT SAHGAL under the guidance of ER.RAMENDRA SINGH NIRANJAN discussed about Design and structural performance analysis of Supra SAE car chassis
- AMOGH RAUT, ANIKET PATIL discussed indetail in International Journal of Engineering and Advanced Technology (IJEAT) ISSN: 2249 8958, Volume-7 Issue-1, October 2017 about Design Analysis of Chassis used in Students Formula Racing Car using FEA Tool
- AJAY KASHIKAR, SHREYAS MHATRE,ANISH, RAHUL CHAVAN, ABHISHEKSHUKLA discussed in detail in International Journal of Research Publications in Engineering and Technology [IJRPET] ISSN: 2454-7875 VOLUME 3, ISSUE 3, March-2017 about Design and Analysis of Formula Car Chassis
- ANKIT PATIL, SAAHIL PATIL, MONIKSHAH, NITIN SALL discussed in detail in International Journal of Scientific & Engineering Research Volume 9, Issue 3, March-2018 about Design and Analysis of Suspension System with Different Material for SUPRA SAE INDIA 2018
- MOHIT SINHA discussed in detail inInternational Journal of Innovative Research in Science, Engineering and Technology Volume 5 Issue 4 April 2016 about Design of a space frame race car chassis entailing rectification of preceding flaws with apt ergonomic considerations, material selection and Impact analysis
- William B. Riley and Albert R. George discussedin detail in SAE Technical Paper Series Reprinted from: Proceedings of the 2002 SAE Motorsports Engineering Conference and Exhibition (P-382) about Design, Analysis and Testing of a Formula SAE Car Chassis.
- Dr. Tanveer Singh Chawla and Mr. Eric Leonhardtdiscussed in detail in 2018 ASEE Annual Conference & Exposition about Two Approaches to Optimize Formula SAE Chassis Design Using Finite Element Analysis
- Jannis D.G. van Kerkhoven, 516303 DCT2008.154 discussed in detail in Technische Universiteit Eindhoven Department Mechanical Engineering Dynamics and Control Technology Group about Design of a Formula Student race car chassis
- Ranjit Kale, Nagesh Koli, Darshan Sonawane, Dipesh Garud, Rohan Korpenwar discussed in detail in International Journal of Innovative Research in Science, Engineering and Technology Vol. 8, Issue 10, October 2019 about Design, Analysis, and Material Selection of a Student Formula Race Car Roll Cage
- P.K. AJEET BABU, M.R. SARAF, K.C. VORAdiscussed in detail in International Mobility Conference ISSN 0148-7191, e-ISSN 2688-3627about Design, Analysis and Testing of the Primary structure of a race car for Supra SAE India Competition
- N. G. Jogi, Piyush Ram Shahade, Akshay KumarKaware discussed in detail in International Journal of Engineering Science Invention ISSN Volume 3 Issue 6 June 2014 PP.22-33 about Analysis of Formula Racing Car Frame Using Ansys
- B. Subramanyam, Vishal, Mahesh Kollati, K.Praveen Kumar discussed in detail in International Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181 IJERTV5IS100046Vol. 5 Issue 10, October-2016 about Analysis of Formula Student Race Car
- DESIGNDevelopmentThe purpose of the body is to rigidly connect the front and rear suspension even as supplying attachment points for the extraordinary systes of the car. Relative movement between the front and rear suspension attachment factors can reason inconsistent handling. The frame must additionally offer attachment factors with the intention to no longer yield within the automobiles overall performance envelope. There are many special types of frames; area frame, monocoque, and ladder are examples of race car frames.The most famous fashion for SUPRA SAEINDIA/FSAE is the tubular space body. Space frames are a series of tubes which are joined together to form a shape that connects all of the important components collectively. However, maximum of the ideas and theories may be implemented to other chassis designs. A Space body chassis changed into selected over a monocoque regardless of being heavy, as its manufacturing is fee- effective, requires easy gear and damages to the chassis can be effortlessly rectified. The chassis layout began with fixing of suspension mounting coordinates and engine tough factors.
The layout manner of the chassis includes many steps, from the preliminary project to the mission of chassis layout to the begin of production. These steps are; to become aware of the restrict, decide the specified overall performance standards, studies layout techniques and technique, use of CAD software program to layout chassis and ultimately begin creation. Throughout those steps, picks should be made based on the objectives which might be to be executed to meet the performance requirement.
The dressmaker of the chassis need to have an idea as to how all additives of the car are going to feature when it comes to every different. As a result, the designer has to understand how all parts ought to interact and take this interplay into account while designing the body. The design of a racing vehicle chassis, or any racing chassis for that be counted, is going to be primarily based on suspension points, powertrain format, driving force function controls, protection, and many others. These vital points must come collectively to form a powerful bundle for the car to perform as meant.
Stiffness – The suspension is designed with the purpose of retaining all four tires flat on the ground at some point of the overall performance range of the vehicle. Generally, suspension structures are designed under the belief that the frame is an inflexible body. For example, undesirable adjustments in camber and toe can arise if the body lacks stiffness. A photograph of a body subjected to a torsional load is superimposed on an undeflected frame. Generally, a chassis that is stiff sufficient for opposition will not yield. However, a few care should be taken to make sure that the attachment points of the frame do now not yield whilst subjected to layout loads. For instance, the engine mounts have to be made stiff enough to reduce the opportunity of failure.
Torsional Stiffness – Torsional stiffness is the resistance of the frame to torsional hundreds. FEA turned into used to research the torsional stiffness of the chassis. In order to design a car of most torsional stiffness the premise or generalized equation for torsion must be examined.
T = JG / l
The above equation is an easy component that relates the attitude of twist to the carried out torque, with J representing the shafts polar second of inertia, with denoting the resultant twist of the shaft, G representing the shear modulus of the cloth and l being the length of the shaft. Now a chassis may be made extremely stiff by way of including vast amounts of cloth to the frame. However, this extra material would possibly degrade the performance of the auto due to the introduced mass. Therefore, while designing a race automobile chassis it is crucial to get a balance among the burden and stiffness of the chassis.
Triangulation – Triangulation can be used to increase the torsional stiffness of a body, in view that a triangle is the handiest form that is continually a shape and now not a mechanism. Obviously, a frame that is a structure will be torsionally stiffer than a mechanism. Therefore, an attempt must be made to triangulate the chassis as an awful lot as possible. Visualizing the frame as a collection of rods that are connected through pin joints can help body designers find the mechanisms in a layout.
Fig 3.1 Frame Triangulation
Designers can also evaluate their frame by using checking to see if every pin jointed node carries at least three rods which complement the load course. It turned into determined to use thin wall metal tubing for the frame design. This required considerable triangulation of the frame, considering that skinny wall tubing plays thoroughly in tension and compression but poorly in bending. The additives which produce big amounts of pressure, as an example the engine and suspension, need to be connected to the frame at triangulated factors.
Suspension Points – The suspension geometry is what determines how well the car controls the tires that connect the vehicle to the floor. Should the suspension now not manipulate the tires efficiently, the automobile will not nook as quickly and therefore be slower ordinary.
Through trying out, facts evaluation, and simulation we’ve evolved powerful suspension geometry for our SUPRA SAEINDIA race vehicle. Packaging of the suspension to the body is typically not an interference trouble when you consider that maximum of the components is exterior to the body. However, it’s far particularly vital to attach the suspension components to stiff portions of the chassis to correctly distribute the hundreds so one can be exceeded thru those components.
Designing the frame so the manipulate arms are attached to a stiff portion of the chassis can on occasion be very hard. By changing the distance among the manage arm pivot points can assist to optimize the weight course for the manipulate fingers. This distance can be modified as it will now not have an effect on the suspension geometry, for the reason that rotational axis of the manage arm isn’t always affected. However, reducing the span of the manipulate arms will lessen the arms capability to react to the forces which can be generated via accelerating or braking. It is suggested that suspension need to be designed simultaneously with the body. This permits the clothier to concentrate at the load paths from the push rods and rockers in order that the body can efficaciously react to the masses.
Powertrain Layout – Correctly attaching the components of the drivetrain to the frame is very important for extended frame life. The relative stiffness among the engine, differential, and body is not as important as while attaching the suspension. This is because of the fact that maximum race automobile chassis layouts have brief distances among the drivetrain components. The major design factor is to make certain that the frame does now not ruin at some point of a wrong downshift or a violent release of the snatch.
Since SUPRA SAEINDIA race automobiles use motorbike engine it is simpler to place the engine as it was within the motorcycle. The region of the engine on the subject of the wheelbase of the car performs the biggest function in weight distribution of the automobile. A smooth manner to combat this is to distribute extra of the weight of the automobile closer to the driven wheels to boom vertical load on the tires. Any exceedingly big mass, being some distance far away from the centerline of the automobile, doubtlessly have a bad effect on the yaw inertia of the automobile.
By shifting the mass to an area inside the middle of the auto will lower the yaw inertia that’s favorable for race motors. When designing the body across the motor and differential on chain pushed designs, sufficient clearance need to exist so that numerous the front and rear sprockets may be used. This clearance lets in a large choice of very last power ratios. Well the extra area may be omitted primarily based upon the clothiers preference, however it’s miles endorsed to have sufficient clearace as incapacity to trade the final power ratio has proven to be a drawback when looking to power the race vehicle inside the confined area of the SUPRA SAEINDIA competition and the greater open spaces of autocross. Ease of preservation is likewise an important layout attention when designing the frame across the drive train. By providing clearance for direct elimination of the engine will lessen the amount of mechanics pressure concerned with engine adjustments.
Driver Position and Controls – Another crucial factor of chassis design is driver positioning and controls. If the driver is not able to operate the automobile readily, it’ll no longer meet its full capability. Designing the frame across the controls, which include the steerage wheel and pedals, is an issue of ensuring that the shape of the frame does now not intervene with the drivers venture. Also, the controls ought to be appropriately supported through the body in order that the attachment factors do no longer yield even as the automobile is being driven. Driver consolation concerns consist of seating perspective, elbow area, head height in relation to the the front of the auto, and controls operation (pedals, shifter, and guidance wheel).
Safety – Fortunately, the FSAE policies committee has set up a group of rules requiring positive tubing sizes in areas of the frame essential to driver protection in the event of an accident. These regulations outline outer diameters and wall thicknesses for the front bulkhead, front roll hoop, fundamental roll hoop, facet impact tubing, roll hoop bracing, and front effect zones. The stated rules are adhered to without deviation so that the motive force can be safe and the car can skip technical inspection at opposition.
packaged near the center of gravity to reduce the outcomes of its various mass at some point of the race.
Fig 3.2 Chassis Planes – Side Views
Modeling of Fixed Elements – Fixed elements include roll hoops, front bulkhead, suspension factors, and engine mounts. These features will no longer be moved round at some point of chassis design new release so that the range of variables able to be manipulated may be decreased.
This allows for a quicker layout period in order that creation may also begin earlier than normal. The roll hoop and bulkhead shapes are determined upon to reduce the duration of tubing for the elements. Since the roll hoops and bulkhead are required to be at least 1 OD .0.5 wall and 1 OD .1/2 wall, respectively, the lengths of this heavy tubing want to be minimized to reduce weight. Once shapes of the functions are decided upon, they may be drawn on their respective planes.
A tubular space frame is designed in several steps which might be based at the layout issues previously said. A methodical plan need to be observed so that all parameters are considered and the layout incorporates a part of the car efficaciously. We designed the SUPRA SAEINDIA race vehicle in Solid works 2014 the usage of the weldment characteristic to model tubes effortlessly and accurately.
Initial Setup – The design changed into initiated by using determining the height, track width, wheel base, and general period dimensions of the car. Stemming from these dimensions were roll hoop places, bulkhead vicinity, cockpit place, engine mounting vicinity, and wheel centerlines for an estimation of weight distribution. Once those dimensions were decided on, a sequence of planes had been created in Solid works at those factors in order that those locations may be visualized. Some idea turned into given to the placement of different crucial or tough-to- package structures. For instance, the gas gadget had to be
Fig 3.3 Roll Hoops and Suspension Points
The suspension mounting points are the next to be designed. These are drawn as constant factors in space in the Solid works version. During suspension design, a premier a-arm span became decided and this dimension ought to now be incorporated into the chassis.
Suspension mounts needs to be welded to the chassis so the placement of this mounts are needed to be obtained from the suspension calculation. Engine mounting places also are determined upon and glued so that the engine layout group can correctly vicinity their individual element models within the automobile assembly while not having to alternate their elements. This continues the team from making drastic changes while farther along in the layout system.
Modeling of Variable Elements – The next step is to version the tubes that connect the fixed elements to each other. Arrangements of these tubes are variable and
careful attention of weight, manufacturability, and chassis stiffness must be taken, in order that the chassis does not come to be heavy and too flexible. The competition rules have to additionally be taken into account whilst drawing those connecting tubes.
Since the load of the chassis is important to vehicle overall performance, connecting tubes must be stored brief and skinny. All the connecting tubes ought to be of the scale specified in the rule e-book i.e., 1 .049 wall. The simplest connecting tubes that won’t be of this length are the required roll hoop bracing tubes which should be 1 .1/2 wall. These bracing tubes are stored to a minimum period. The first chassis layout underneath had a whole lot of structural contributors which in-fact improved the weight of the chassis. The most important purpose of growing the quantity of structural contributors turned into to increase the torsional stiffness. By Finite Element Analysis the individuals which werent of any use had been removed and therefore it reduced the weight without affecting a good deal the torsional stiffness
Manufacturability is vital to endure in thoughts because the greater complex the chassis, the more difficult it will be to manufacture. If the connecting tubes have extraordinarily tough notches at the ends, it will take the team member who’s making that tube a lot longer to finish. Subsequently, if every tube at the chassis takes 2 or extra hours to notch, then it’s going to take plenty longer to complete the frame.
Chassis stiffness relies on the powerful association of the connecting tubes. This will be discussed in further detail later. Modeling of the connecting tubes is exceptionally easy in Solid works the usage of the 3-d caricature tool. Drawing the strains is just like connecting the dots, or in this example, nodes. Once a line is drawn among of the nodes, a structural member may be located alongside that line. A community of tubes may additionally then be drawn by connecting nodes in certain locations and placing structural participants.
- ANALYISTORSIONAL ANALYSIS
- CONCLUSIONThe purpose of this assignment become to design a chassis for a competition, a goal that has been completed. In the work accomplished, a frame is designed that’s inflexible sufficient no longer to deform beneath acceleration and braking masses and on the same time maintain all the components together. The work was started out with a fundamental design of body which would meet the whole design requirement. Chassis was observed to be secure appreciably in static (bending) and dynamic (acceleration) modes with pressure values pretty much less than the yield power. The dominant characteristic of structural behavior viz. Torsional rigidity multiplied three instances with a median boom inside the wall thickness.The cause of this thesis project is not handiest to layout the roll cage for the 2019 SUPRA SAEINDA automobile, however also to offer an intensive study inside the method taken to arrive on the final layout. With the general design being cautiously considered beforehand, the producing manner being managed carefully, and that many design functions had been established effective within the performance requirement f the vehicle.During the design method, the crew should obtain a compromise among price, manufacturing, overall performance, and design time in order that their car may be competitive in all aspects of the SUPRA SAEINDIA competition. The timeline of the competition, mixed with the rigorous schedule of college, limits the variety of iterations for each layout. However, the group ought to take into account that it’ll take several iterations to converge on a first-class design. The amount of time used for the layout procedure subtracts from the time to be had for manufacturing and checking out. Although this paper has focused on design, it is very critical to check the auto in order that any design oversights could be highlighted earlier than opposition.
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