[Patel et al., 5(9): September, 2016] ISSN: 2277-9655 IC™ Value: 3.00 Impact Factor: 4.116 IJESRT INTERNATIONAL JOURNAL OF ENGINEERING SCIENCES & RESEARCH TECHNOLOGY DESIGN AND ANALYSIS OF TATA 2518TC TRUCK CHASSIS FRAME WITH VARIOUS CROSS SECTIONS USING CAE TOOLS Akash Singh Patel *, Jaideep Chitransh Department of Mechanical Engineering, UCER, Allahabad, India DOI: 10.5281/zenodo.155097 ABSTRACT Chassis is the French word was used to denote the frame parts or main structure of vehicle, which is now, denotes the whole vehicle except body in case of heavy vehicles (that is vehicle without body is called chassis). In case of light vehicles of mono construction, it denotes the whole vehicle except additional fittings in the body. Automobile chassis usually refers to the lower body of the vehicle including the tires, engine, frame, driveline and suspension. Out of these, the frame provides necessary support to the vehicle components placed on it. Role of the chassis frame is to provide a structural platform that can connect the front and rear suspension without excessive deflection. Also, it should be rigid enough to withstand the shock, twist, vibration and other stresses caused due to sudden braking, acceleration, shocking road condition, centrifugal force while cornering and forces induced by its components. So, strength and stiffness are two main criteria for the design of the chassis. The present study has analyzed the various literatures. After a careful analysis of various research studies conducted so for it has been found that there is the scope of optimizing different factors like weight, stress-strain values and deformation etc. by varying cross sections for modeling and analysis. This paper describes the design and Structural analysis of the heavy vehicle chassis with constraints of maximum stress, strain and deflection of chassis under maximum load. In the present work, the dimension of the TATA 2518TC chassis is used for the structural analysis of the heavy vehicle chassis by considering three different cross-sections, Namely C, I, and Hollow Rectangular (Box) type cross sections subjected to the same conditions. A three dimensional solid Modeled in the CAE software CATIA and analyzed in ANSYS. The numerical results are validated with analytical calculation considering the stress distribution and deformation. KEYWORDS: Heavy truck chassis frame, CATIA, ANSYS, FEM, Assembly weight, stress, deformation. INTRODUCTION The major challenge in today’s ground vehicle industry is to overcome the increasing demands for higher performance, lower weight, and longer life of components, all this at a reasonable cost and in a short period of time. The chassis of trucks is the backbone of vehicles and integrates the main truck component systems such as the axles, suspension, power train, cab and trailer. Since the truck chassis is a major component in the vehicle system, it is often identified for refinement. There are many industrial sectors using this truck for their transportations such as the logistics, agricultures, factories and other industries [1]. The chassis frame consists of side members attached with a series of cross members Stress analysis using Finite Element Method (FEM) used to locate the critical point which has the highest stress. This critical point is one of the factors that may cause the fatigue failure. The magnitude of the stress used to predict the life span of the truck chassis [2]. http: // www.ijesrt.com © International Journal of Engineering Sciences & Research Technology [692] [Patel et al., 5(9): September, 2016] ISSN: 2277-9655 IC™ Value: 3.00 Impact Factor: 4.116 Principal Functions Provide mounting points for the suspensions, the steering mechanism, the engine and gearbox, the final drive, the fuel tank and the seating for the occupants. Protect the occupants against external impact,To safety carry the maximum load, Holding all components together while driving, Accommodate twisting on even road surface, Endure shock loading, It must absorb engine and driveline torque [3]. Layout of Chassis Chassis is an important part of automobile. The chassis serves as a frame for supporting the body and different units of automobile like engine, suspension, gearbox, braking system, steering, propeller shaft, differential, axle assemblies, etc. are welded or bolted as shown in fig.1[4]. Fig: 1 Line diagrams of chassis Types of chassis 1.Ladder Frame chassis Ladder chassis is considered to be one of the oldest forms of automotive chassis or automobile chassis that is still been used by most of the SUVs till today. It is also resembles a shape of a ladder which having two longitudinal rails inter linked by several lateral and cross braces asshown in fig.2 [5]. Fig: 2 Ladder frame chassis 2. Backbone chassis The other type of chassis is backbone chassis which has a rectangular tube like backbone and simple in structure. It usually made up of glass fiber that is used for joining front and rear axle together and responsible for most of the mechanical strength of the framework. The space within the structure is used for positioning the drive shaft in case a rear-wheel drive. This type of chassis is strong enough to provide support smaller sports car besides it is easy to make and cost effective [5]. http: // www.ijesrt.com © International Journal of Engineering Sciences & Research Technology [693] [Patel et al., 5(9): September, 2016] ISSN: 2277-9655 IC™ Value: 3.00 Impact Factor: 4.116 Fig: 3 Backbone chassis 3. Monocoque Chassis As for monocoque chassis, most modern cars now a days use this type of chassis. A monocoque chassis is a single piece of framework that gives shape to the car. A one-piece chassis is built by welding several pieces together. It is different from the ladder and backbone chassis as unlike them incorporated with the body in a single piece, whereas the former only support the stress members. The demanding of a monocoque chassis highly increased since it is cost effective and suitable for robotized production [5]. Fig: 4 Monocoque chassis 4. Tubular space frame chassis In this study, it is decided that tubular space frame chassis is used for the urban car. Since ladder chassis is not strong enough, motor racing engineers have developed a 3-dimensional design which known as tubular space frame. Tubular space frame chassis employs dozens of circular-section tubes (some may use square section tubes for easier connection to the body panels though circular section provides the maximum strength), position in different directions to provide mechanical strength against forces from anywhere. These tubes are welded together and form a complex structure [5]. Fig: 5 Space frame chassis LITERATURE REVIEW Literature Survey Many researchers carried out study on truck chassis as follows: Patel et al [1] have investigated and optimized a chassis design for Weight reduction of TATA 2516TC chassis frame using Pro-Mechanica. Thy first find out the assembly weight, maximum stress, strain and displacement for the existing section of chassis by using ANSYS Software after then they modified the dimensions of existing C-sections and again find all and concluded that the existing “C” sections is better than all the sections with respect to the Stress, Displacement, Strain and Shear stress except the weight. For the weight consideration modified “C” section has less weight than the all sections which are studying in this paper. Finally By the use of modified “C” section, http: // www.ijesrt.com © International Journal of Engineering Sciences & Research Technology [694] [Patel et al., 5(9): September, 2016] ISSN: 2277-9655 IC™ Value: 3.00 Impact Factor: 4.116 105.50 Kg (11 %) weight is saved per chassis assembly an.d in same manner cost may also be reduced approximately 11%. From the results, modified “C” sections are used as an optimized section. Murali et al [2] have investigated the critical point which has the highest stress using Finite Element Method (FEM). This critical point is one of the factors that may cause the fatigue failure. For the modifications and analysis, the existing truck chassis were added with stiffeners. Initially the thickness of the model, where the maximum deflection occurs in bending analysis was increased to certain value with acceptable limit. And one more cross beam was added at the center of the wheel base to add stiffness to the model. Series of modifications and tests were conducted by adding the stiffener in order to strengthen and improved the chassis stiffness as well as the overall chassis performances. S. Prabakaran and K. Gunasekar [3] have studies the Structural Analysis of EICHER E2 (or 11.10) Chassis Frame for the existing C-section. They first find out the assembly weight, maximum shear stress, maximum equivalent stress and displacement for the existing C-section of chassis by using SOLID WORKS and ANSYS Software and then they modified the existing C-section taking three different cases and find out the parameters for all cases. They have investigated that the weight, maximum shear stress, maximum equivalent stress and displacement for the third case are reduced respectively 6.68%, 12.14 %, 8.55 % and 11.20 %. So they concluded that by using FEM software we can optimize the weight of the chassis frame and it is possible to analyze modified chassis frame before manufacturing. B. Ramana Naik and C. Shashikanth [4] have objective to analyze an automobile chassis for a 10 tonne vehicle. The modeling is done using Pro-E, and analysis is done using ANSYS. The overhangs of the chassis are calculated for the stresses and deflections analytically and are compared with the results obtained with the analysis software. Modal Analysis is also done to find the natural frequency of the chassis and seen that it is above than its excitation frequency. The Theoretical calculations and FE analysis results are compared and it is observed that they are within the material properties. This frequency is more than 4 times the highest frequency of the excitation (i.e. 33 Hz) hence the chassis can faithfully transmit the input excitation to the vehicle body without any amplification. Kamlesh Y. Patil and Eknath R. Deore [5] have studies the Ladder Chassis frame of TATA 912 Diesel Bus and The model of the chassis was created in Pro-E and analyzed with ANSYS for Various Cross Sections for same load conditions. They observed that the Rectangular Box (Hollow) section is more strength full than the conventional steel alloy chassis with C and I design specifications. The Rectangular Box (Hollow) section is having least deflection i.e., 2.683 mm and stress is 127 N/mm2 in all the three type of chassis of different cross section. Sharma et al [6] have studies the chassis of a Heavy Vehicle TATA LPS 2515 EX with three different alloys subjected to the same conditions of the steel chassis. The three material used for the chassis are grey cast iron, AISI4130 alloy steel and ASTM A710 STEEL GRADE A. The three different vehicle chassis have been modeled by considering three different cross-sections. Namely C, I, and Box type cross sections. A three dimensional solid Model was built in the CAE software CATIA V5 parametric and the analysis was done in ANSYS-14.5. The results shows that the default material for the chassis i.e. A709M Grade 345 W Structure steel shows strength equal to the AISI 4130 steel alloy but in case of the deformation AISI 4130 alloy is superior to structure steel. So, for the consideration of alloy for the chassis AISI 4130 alloys is better than others and for different cross sections of the chassis C-section chassis is suitable for the heavy trucks. Lenin et al [7] modeled a chassis used in a TATA ACE using CATIA. Structural and modal analyses are done on chassis using ANSYS. The analysis is done using three materials Cast Iron, Aluminum and E-GLASS EPOXY. By observing structural analysis results, the stress values for Glass Epoxy and E –Glass Epoxy are less than their respective allowable stress values. So using composites for chassis is safe. From the obtained ANSYS results it was found that the suitable proposed material for automotive chassis is Glass Fiber Reinforced Plastic Materials. But, when compared with GFRP the cost of CFRP will be higher therefore here considered that, the GFRP material is suitable for automotive chassis. Also when compared different section it is found that the I-section will be suitable for this application. http: // www.ijesrt.com © International Journal of Engineering Sciences & Research Technology [695] [Patel et al., 5(9): September, 2016] ISSN: 2277-9655 IC™ Value: 3.00 Impact Factor: 4.116 Vijay Kumar V. Patel and Prof. R. I. Patel [11] have investigated and optimized a chassis design of EICHER E2 (or 11.10) for Weight Reduction same manner as done by S. Prabakaran and K. Gunasekar but they used Pro-E softer for modeling and find the same results. Patel et al [14] have investigated the stress and deformation developed in chassis frame of EICHER 11.10. The model of the chassis has been developed in SOLID WORKS 2009 and static structural analysis has been done in ANSYS workbench. The analysis gives maximum shear stress and total deformation which are in desired limit, so the design is safe. Potdar et al [15] used approximate dimensions to model the N1 type TATA Ace chassis. Software used was CATIA V5 for modeling and ANSYS Workbench for analysis. Concluded that the deflection due to bending of the Chassis Members can be evaluated using Static Finite Element Analysis instead of conventional time consuming calculations. The overall bending stiffness of the Chassis is 13724 N/m which is under 22000N/m, permissible range for N1 Vehicle Category. Problem Formulation The present study has analyzed the various literatures. After a careful analysis of various research studies conducted so for it has been found that there is the scope of optimizing different factors like weight, stress-strain values and deformation etc. by varying cross sections for modeling and analysis. This paper describes the design, Structural analysis & optimization of the heavy vehicle chassis with constraints of maximum stress, strain and deflection of chassis under maximum load. Our work is to design and analyze the heavy vehicle chassis to reduce weight, stress- strain values and deformation etc. Objectives of proposed work In the present work, the dimension of the TATA 2518TC chassis is used for the structural analysis of the heavy vehicle chassis modeled by considering three different cross-sections, namely C, I, and Rectangular Box (Hollow) type cross sections subjected to the same condition. A three dimensional solid Modeled in the CAE software CATIA V5 and analyzed in ANSYS 14.0. The numerical results will be validated with analytical calculation considering the stress distribution, deformation. CHASSIS FRAME CROSS SECTIONS To appreciate the design and construction of a vehicle’s chassis an understanding of the operational environment is necessary. Once the operating conditions are known, a comparison of the different available chassis-member cross- section shapes can be made. The flowing sections examine and illustrate the basic requirements of the chassis. 1. “C”-Channel sections It has good resistance to bending, used in long section of the frame [1]. Fig: 6 “C”-Channel sections http: // www.ijesrt.com © International Journal of Engineering Sciences & Research Technology [696] [Patel et al., 5(9): September, 2016] ISSN: 2277-9655 IC™ Value: 3.00 Impact Factor: 4.116 2. “I”- Sections It has good resistance to both bending and torsion. Due to clamping reason generally “I” section is not used for the practical use. Fig: 7 “I”- Sections 3. Box sections It has good resistance to both bending and torsion, used in short members of frames. Fig: 8 Box- Sections 4. Tubular sections It has good resistance to torsion. Tubular section is used these days in three wheelers, scooters pick-ups and bicycle. Fig: 9 Tubular sections CHASSIS FRAME MATERIAL Currently the material used for the chassis (TATA 2518TC) is as per IS: - 9345 standard is structural steel with St 37. Structural steel in simple words with the varying chemical composition leading to changes in names. The typical chemical composition of the material is[6]: 0.565%C, 1.8% Si, 0.7%Mn, 0.045%P and 0.045%S. Physical Property of the ST37:- Modulus of Elasticity = 210 GPa = 2.10 x 105 N / mm2 Density = 7850 kg/m3 Ultimate Tensile Strength = 460 MPa = 460 N / mm2 Yield Strength = 260 MPa = 260 N / mm2 Poisson Ratio = 0.29 http: // www.ijesrt.com © International Journal of Engineering Sciences & Research Technology [697] [Patel et al., 5(9): September, 2016] ISSN: 2277-9655 IC™ Value: 3.00 Impact Factor: 4.116 ANALYTICAL CALCULATIONS Table: 1 Specification of Existing Heavy Vehicle TATA LPT 2518 TC Truck Chassis frame S. No. Parameters Value 1 Total length of the chassis 9010 mm 2 Width of the chassis 2440 mm 3 Wheel Base 4880 mm 4 Front Overhang 1260 mm 5 Rear Overhang 2155 mm 6 Ground Clearance 250 mm 7 Capacity (GVW) 25 ton 8 Kerb Weight 5750 Kgs 9 Payload 19250 Kgs Side bar of the existing chassis frame are made from “C” Channels with Height (H) = 285 mm, Width (B) = 65mm, Thickness (t) = 7 mm Basic Calculation for Chassis Frame Model No. = LPT 2518 TC (TATA) Capacity of Truck = 25 ton (Kerb Weight+ Payload) = 25000 kg = 245250 N Capacity of Truck with 1.25% = 245250 * 1.25 N = 306562 N Total Load acting on the Chassis = 306562 N All parts of the chassis are made from “C” Channels with 285mm x 65mm x 7mm. Each Truck chassis has two beams. So load acting on each beam is half of the Total load acting on the chassis. Load acting on the single frame = Total load acting on the chassis / 2 = 306562 /2 =153281 N / Beam Loading Conditions Beam is simply clamp with Shock Absorber and Leaf Spring. So Beam is a Simply Supported Beam with uniformly distributed load. Load acting on Entire span of the beam is 153281 N. Length of the Beam is 9010 mm. Uniformly Distributed Load is 153281 / 9010 = 17.0 N/mm According to loading condition of the beam, a beam has a support of three axle means by three wheel axles C, D and E. Total load reaction generated on the beam is as under:- Fig: 10 Total load generated on the beam http: // www.ijesrt.com © International Journal of Engineering Sciences & Research Technology [698] [Patel et al., 5(9): September, 2016] ISSN: 2277-9655 IC™ Value: 3.00 Impact Factor: 4.116 Fixed End Moment This is the indeterminate structure of beam. Fig: 11 Consideration of fixed end moments M̅ = 17∗1260∗1260 = 13494600 N mm CA 2 M̅ = −17∗4165∗4165 = -24575235.42 N mm CD 12 M̅ = +24575235.42 N mm DC M̅ = −17∗1430∗1430 = -2896941.667 N mm DE 12 M̅ = +2896941.667 N mm ED M̅ = −17∗2155∗2155 = -39474212.5 N mm EB 2 Total restraint moment at “C” M̅ = M̅ + M̅ = 13494600 -24575235.42 = -11037364.58 N mm C CA CD Total restraint moment at “E” M̅ = M̅ + M̅ = 2896941.667 -39474212.5= -36577270.83 N mm E ED EB For the span “CD” M = - M̅ = -13494600 N mm CD CA M = M̅ - M̅ \2+ 3𝐸𝐼 i = 24575235.42 + 11037364.58\2 + 3𝐸𝐼 i DC DC C b b 𝑙 4165 3𝐸𝐼 = 30093917.71 + i b 4165 For the span “DE” M = - M̅ = 39474212.5 N mm ED EB M = M̅ - M̅ \2+ 3𝐸𝐼 i = -2896941.667 + 36577270.83\2 + 3𝐸𝐼 i DE DE E b b 𝑙 1430 3𝐸𝐼 = 15391693.75 + i b 1430 Equilibrium condition at “D” M̅ + M̅ = 0 DC DE 3𝐸𝐼 3𝐸𝐼 30093917.71 + i + 15391693.75 + i = 0 b b 4165 1430 EI i = - 1.624486 * 1010 b Substituting the value of EI i b M = 18392938.12 N mm DC M = - 18688432.12 N mm DE http: // www.ijesrt.com © International Journal of Engineering Sciences & Research Technology [699] [Patel et al., 5(9): September, 2016] ISSN: 2277-9655 IC™ Value: 3.00 Impact Factor: 4.116 Fig:12 Fixed end moments Calculations for Reaction and Shear Force Diagram R =17 * 1260 = 21420 N ( ↑ ) CL 17∗4165 13494600−18688432.12 R = + = 34155.48 N ( ↑ ) CR 2 4165 R = 17*4165 – 34155.48 = 36649.52 N ( ↑ ) DL 17∗1430 18688432.12−39474212.5 R = + = - 2380.51 N ( ↓ ) DR 2 1430 R = 17*1430 + 2380.51 = 26690.51 N ( ↑ ) EL R = 17*2155 = 36635 N ( ↑ ) ER ∴ R = R + R = 55575.48 N ( ↑ ) C CL CR R = R + R = 34269.01 N ( ↑ ) D DL DR R = R + R = 63325.51 N ( ↑ ) E EL ER Fig: 13 Shear Force Diagram Calculations for Bending Moment Diagram:- M = 0 N mm A M = - M̅ = - 13494600 N mm C CA 17∗ 4165∗ 4165 M = = 36862853.13 N mm P 8 M = M = - 18688432.12 N mm D DE 17∗ 1430∗ 1430 M = = 4345412.5 N mm Q 8 http: // www.ijesrt.com © International Journal of Engineering Sciences & Research Technology [700] [Patel et al., 5(9): September, 2016] ISSN: 2277-9655 IC™ Value: 3.00 Impact Factor: 4.116 M = M̅ = -39474212.5 N mm E EB M = 0 N B So the maximum bending moment occurs at “E” M = M = -39474212.5 N mm max E Fig: 14 Bending Moment Diagram Calculations for the Maximum Deflection Fig: 15 Reaction generated on the beam We consider a section x-x in “EB” span at x distance from A. Taking moment of all forces about x-x section M = -8.5x2 + R (x-1260) + R (x-5425) + R (x-6855) xx C D E According to Macaulay’s theorem M = EI 𝑑2𝑦 = -8.5x2 + R (x-1260) + R (x-5425) + R (x-6855) xx 𝑑𝑥2 C D E On integrating with respect to x we get 𝑑𝑦 −17x3 (x−1260)2 (x−5425)2 (x−6855)2 EI = +C +R +R +R 1 C D E 𝑑𝑥 6 2 2 2 Again integrating with respect to x we get −17x4 (x−1260)3 (x−5425)3 (x−6855)3 EIy = +C x + C +R +R +R ⋯⋯⋯1 1 2 C D E 24 6 6 6 Applying the boundary conditions At x = 1260mm, y = 0 −17∗12604 0 = +C * 1260 + C ⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯2 1 2 24 http: // www.ijesrt.com © International Journal of Engineering Sciences & Research Technology [701]