VIBRATION ANALYSIS OF REAR AXLE OF TATA ACE

� DEPARTMENT OF MECHANICAL ENGINEERING

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NETAJI SUBHASH ENGINEERING COLLEGE

TECHNO CITY, GARIA, KOLKATA – 700 152

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Under the guidance of

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PROF. SUBHRAJYOTI SARKAR

PROJECT SUBMITTED BY:

ABSTRACT

In mechanical engineering, some machine components can behave differently due to the design of machine elements, manufacturing processes, and selection of materials. To understand basic phenomena of any general dynamic stresses, it is good to understand adequate modeling of the system. To start with, a lateral vibration analysis of the shaft is considered. It is well known that lateral bending, whirling and transverse vibration of propulsion systems phenomenon is not as dangerous as the torsional vibration. This study is focusing on the lateral frequencies and the mode shapes of three different materials. The main issue of the lateral frequency is that could cause resonance and fatigue in the material.

KEY WORDS:

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• Lateral vibration

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• Natural frequencies

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• Resonance

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• Stainless steel

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• Aluminium alloy

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• Grey cast iron

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CONTENTS

INTRODUCTION

The rear axle is an essential component of any vehicle, including commercial vehicles like the Tata Ace. It plays a crucial role in transmitting power from the engine to the wheels and supporting the weight of the vehicle. However, various factors can lead to vibrations in the rear axle, which can negatively impact the vehicle's performance, stability, and overall driving experience.

Vibration analysis of the rear axle of the Tata Ace involves studying and evaluating the vibrational behavior of the axle system to identify potential issues and their root causes. By conducting a comprehensive vibration analysis, engineers and technicians can gain insights into the dynamic characteristics of the rear axle, such as natural frequencies, mode shapes, and resonance conditions.

REVIEW ON MATERIALS

• The selection of the material is one of the most important elements in engineering design. Also it’s an important stage to start the project because some material has its own optimum properties or sometimes it’s a combination of properties between two materials to get the best properties needed.
• The benefits of material consideration are to reduce the cost and also to improve the performance. Additionally, elements of this materials selection process involve deciding on the problem and from those criteria can see which material is the best to maximize the performance. The component that been chosen to discuss on is a solid rod shaft that is used to transmit the movement. There are different materials can be used depend on the cost of the material, the weight and the strength.

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• STAINLESS STEEL:

Stainless steel is a type of steel alloy that contains a minimum of 10.5% chromium content by mass. It is known for its corrosion resistance and high durability, making it a popular choice for various applications in different industries.

Here are some key characteristics and features of stainless steel:

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• Corrosion Resistance: The presence of chromium in stainless steel forms a thin, protective oxide layer on the surface, which helps to resist corrosion and staining. This makes stainless steel suitable for use in environments where exposure to moisture or harsh chemicals is a concern.

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• Strength and Durability: Stainless steel is a strong material that offers excellent mechanical properties. It is resistant to impact, heat, and wear, making it suitable for applications that require high strength and durability.

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• GREY CAST IRON:

Grey cast iron, also known as gray iron, is a type of iron-carbon alloy that contains graphite flakes in its microstructure. It is called "grey" cast iron because of the characteristic grey color of its fracture surface. Grey cast iron is widely used in various industrial applications due to its unique properties and cost-effectiveness.

Here are some key characteristics and features of grey cast iron:

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• Composition: Grey cast iron typically contains around 2-4% carbon and 1-3% silicon, along with small amounts of other elements such as manganese, sulfur, and phosphorus. The graphite flakes in its structure give it its distinctive appearance.
• Graphite Formation: The presence of carbon in grey cast iron allows graphite to form during solidification. The graphite flakes act as internal lubricants, providing good machinability and reducing friction between the metal grains.

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• ALUMINIUM ALLOY:

Aluminium alloy refers to a combination of aluminium with other elements to enhance its mechanical properties for specific applications. Aluminium alloys offer a lightweight, corrosion-resistant, and high-strength alternative to many other materials. They are widely used in various industries, including aerospace, automotive, construction, and consumer goods.

Here are some key characteristics and features of aluminium alloys:

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• Lightweight: Aluminium is a lightweight metal, making it an attractive choice for applications where weight reduction is essential. Aluminium alloys can offer significant weight savings compared to steel or other metals, leading to improved fuel efficiency in transportation and increased payload capacity in aerospace.

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• Corrosion Resistance: Aluminium naturally forms a thin oxide layer on its surface, providing inherent corrosion resistance. Alloying elements such as copper, magnesium, or zinc can further enhance this property, making aluminium alloys highly resistant to rust and corrosion. This characteristic makes them suitable for outdoor or marine applications.

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PROPERTIES OF MATERIALS

REAR AXLE DRIVE

Rear axle drive, also known as rear-wheel drive (RWD), is a configuration commonly used in vehicles where the power from the engine is transmitted to the rear wheels for propulsion. In this setup, the front wheels are responsible for steering, while the rear wheels provide the driving force.

Here are some key features and characteristics of rear axle drive:

• Power Transmission: In a rear axle drive system, the engine's power is transmitted from the transmission or gearbox to a differential, which is located on the rear axle. The differential distributes the power evenly between the two rear wheels, allowing them to rotate at different speeds when cornering.

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• Weight Distribution: Rear axle drive vehicles tend to have a more balanced weight distribution compared to front-wheel drive (FWD) or all-wheel drive (AWD) configurations. The weight of the engine and transmission is usually situated over the front wheels, while the rear wheels bear the weight of the vehicle body and passengers.

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• Traction: Rear axle drive vehicles typically exhibit good traction, especially during acceleration. The weight transfer to the rear wheels under acceleration increases the amount of downward force on those wheels, improving their grip on the road surface.

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• Handling Characteristics: Rear axle drive vehicles often offer a more engaging and dynamic driving experience. With the front wheels responsible for steering and the rear wheels providing propulsion, the vehicle can have a more balanced and predictable feel. RWD vehicles tend to have better weight transfer during acceleration and deceleration, allowing for improved handling and stability, particularly in performance cars.

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MAIN OBJECTIVES

All the Vehicles, aircraft and home appliances mechanical components are with shafts, so it becomes necessary to study vibration analysis of a shaft. The following are main objective of this analysis.

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1. To design of rear axle with one ends spur geared.

2. To Analysis of rear axle with one ends spur geared using FEA Method.

3. Vibration Reduction of the rear axle by choosing a suitable material.

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MATHEMATICAL ANALYSIS OF VIBRATION OF A SHAFT

Here, we choose a shaft with dimension:

Length = 700 mm , Diameter = 50 mm

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THEORETICAL CALCULATIONS:

Deformation Beam = Y = e / ((ωn/ω)²−1)

• Where,

e = Eccentricity of Center of Mass

ωn = Critical Angular Speed =√(𝑘/𝑚)

ω = Angular Speed

k = Flexural Stiffness of Beam = 48𝐸𝐼/𝑙³

m = Mass of Beam

E = Young’s Modulus

I = Moment of Inertia

L = Length of Shaft

NUMERICAL ANALYSIS ON ANSYS

• Basic Steps of Finite Element Analysis :

There are three basic steps involved in this procedure,

1. Pre Processor (Building the model (or) Modeling)

2. Solution (Applying loads and solving)

3. Post Processor (Reviewing the results)

The finite element method (FEM) is a numerical technique used to approximate and solve complex engineering and mathematical problems. It is a widely adopted method in various fields such as structural analysis, fluid dynamics, heat transfer, electromagnetics, and more.

The core idea behind the finite element method is to divide a continuous problem into smaller, simpler subdomains called finite elements. These elements are interconnected at specific points called nodes, forming a mesh or grid. The behavior of the problem within each element is approximated using mathematical functions known as shape functions.

The finite element method involves the following steps:

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• Discretization: The domain of the problem is divided into a finite number of elements. The shape and size of these elements can vary depending on the problem and the desired accuracy.
• Formulation of governing equations: The behavior of the problem within each element is described using governing equations derived from physical laws. These equations represent relationships between the unknowns (e.g., displacements, temperatures, velocities) and the applied loads or boundary conditions.
• Assembly: The element equations are combined to form a system of equations that describes the behavior of the entire problem. This is done by assembling the element stiffness matrices and load vectors into a global stiffness matrix and load vector.
• Solution: The system of equations is solved to obtain the unknowns within each element. Various numerical methods can be employed for this step, such as direct solvers or iterative techniques.
• Post-processing: Once the unknowns are obtained, post-processing is performed to extract relevant information from the solution. This can involve calculating quantities of interest, such as stresses, strains, heat fluxes, or fluid velocities, and visualizing the results.

RESULTS AND DISCUSSIONS

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• Stainless steel:

The simulation analysis results of the Stainless steel whirling shaft based on the results, it shows that the natural frequency of the first mode for the simply supported shaft is 0Hz. The natural frequency of the second mode for the simply supported shaft is 182.61Hz.

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• Grey cast iron :

The simulation analysis results of the Stainless steel whirling shaft based on the results, it shows that the natural frequency of the first mode for the simply supported shaft is 0.000217 Hz. The natural frequency of the second mode for the simply supported shaft is 143.04 Hz.

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• Aluminium Alloy :

The simulation analysis results of the Stainless steel whirling shaft based on the results, it shows that the natural frequency of the first mode for the simply supported shaft is 0Hz. The natural frequency of the second mode for the simply supported shaft is 185.25 Hz.

BENEFITS OF OUR PROJECT

We have done a research on vibration analysis of the Rear Axle of TATA ACE Goods Carrier. From this Research we have collect a data of dimension and materials type of Rear axle. Now a days Stainless Steel material is used to make rear axle for TATA ACE.

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• We have done analysis on two different materials along with stainless steel. We observed both the deformation as well as the cost of the selected material. From this analysis we have seen that the deformation of Stainless Steel and Grey Cast Iron are almost same and adjustable to the car. But the cost of Grey Cast Iron is very much low than Stainless steel.

So for these two reason we suggest to choose Grey Cast Iron to make shaft of rear axle.

CONCLUSION

As a conclusion, this project has achieved its aims and objectives successfully. The natural frequencies and the mode shapes of the shaft using theoretical calculation method were obtained. The comparison between theoretical values and the simulation is calculated from the results it shows the different frequencies of the first three mode shapes. There were three different materials of shafts to study the effect of the material on the lateral frequency. From the results above we can see each case and how it reacts to the frequencies.

The main point of this research is to avoid that type of dangers phenomenon which is known as resonance which will lead to deflection and causes the structures to fail unexpectedly with minimal cost.

REFERENCE

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• Abu Talib, A., Ali, A., A. Badie, M., Che Lah, N.A., & Golestaneh, A. (2009). Developing a hybrid,
• carbon/glass fiber-reinforced, epoxy composite automotive drive shaft
• Ashby, (2011). Materials Selection For A Torsionally Stressed Cylindrical Shaft
• Bai, B., Zhang, L., Guo, T., & Liu, C. (2011). Analysis of Dynamic Characteristics of the Main Shaft
• System in a Hydro-turbine Based on ANSYS
• Gladwel, G.M.L., & Bishop, R.E.D. (1959). THE VIBRATION OF ROTATING SHAFTS
• SUPPORTED IN FLEXIBLE BEARINGS, William, T.T. (1993). Theory of Vibration with
• Applications Fourth Edition. University of California.J. Clerk Maxwell, A Treatise on
• Jang, E., Park, Y., Muszynska, A., & Kim, C. (1996). Identification of the Quadrature Resonances

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THANK YOU