DESIGN AND ANALYSIS OF DRUM BRAKES

Transcription

1 DESIGN AND ANALYSIS OF DRUM BRAKES 1 DVSRBM SUBRAMANYAM 2 L.SRAVANI. 1 Associate Professor of Mechanical Engineering, nalanda institute of engineering and technology, satenapalli, Guntur, Andhra Pradesh pg Scholar, Departmentof Mechanical Engineering,nalanda institute of engineering and technology, satenapalli, Guntur, Andhra Pradesh ABSTRACT A brake is a mechanical device which inhibits motion. A drum brake is a brake that uses friction caused by a set of shoes or pads that press against a rotating drum-shaped part called a brake drum. The brake drum is a critical component that experiences high temperatures and develop thermal stresses during application of brakes. In addition, the application of shoe pressure gives rise to mechanical loads. So the analysis takes into account both the thermal stresses and mechanical stresses together. Brakes in cars and trucks are safety parts. Requirements not only in performance but also in comfort, serviceability and working lifetime are high and rising. i.e. the brake pad with the friction material, the counter body and caliper, can be modeled. So in this project we design the model of drum brake (drum, & pads) in solid works 2016 and structural and thermal analysis are performed in ansys work bench software 1. INTRODUCTION A brake is a device which is used to bring to rest or slow down a moving body. Safe operation of vehicle demands dependable brakes is required to absorb the kinetic energy of the moving parts or the potential energy of the object being lowered by host when the rate of descent is controlled. The energy absorbed by brakes is dissipated in the form of heat. This heat is dissipated in the surrounding atmosphere to stop the vehicle, so the brake system should have following requirements: The brakes must be strong enough to stop the vehicle with in a minimum distance in an emergency. The driver must have proper control over the vehicle during braking and vehicle must not skid. The brakes must have well anti fade characteristics i.e. their effectiveness should not decrease with is constant prolonged application. The brakes should have well anti wear properties.the important requirements of the brake drum are following: It should provide a surface having well anti wear qualities. It should allow the optimum rate of heat transfer. Heat is generated during each brake application and it must be dissipated to the atmosphere immediately, because the next brake application would again produce more heat. Any excess heating of brakes would cause the drum to expand resulting in loss of

2 effective pedal travel and fading of brake lining. It should have sufficient strength but minimum weight. It should be able to be accommodated within the wheel space available. 2. LITERATURE SURVEY Allan Michael Lang [1] in his research concluded that no simple relationship exists between the natural frequencies of the brake components and the squeal frequency and during squeal both the drum and shoes hold complex modes, which can be best visualized as the superposition of pairs of similar normal modes phase shifted both spatially and in time relative to each other. Mohd Zald Bin Akop [2] in his project concluded that safety aspect in automotive engineering has been considered as a number one priority in development of new vehicle and it is a must for all vehicles to have proper brake system. Ramesha.D.K et al [3] in his thesis concluded that the maximum temperature obtained for aluminum alloy brake drum is less as compared to the cast iron brake drum for a truck. Also, concluded that thermal deformation is less for aluminum alloy brake drum than the cast iron brake drum. As his study states that the weight of Aluminum is lesser than the Cast iron, it is better to use the Aluminum material in the construction of brake drum. NurulhudaBinti Khalid [4] In his project concluded that the temperature changes on the brake drum during the deceleration providing the heat distribution and the distribution of temperature depends on the various factors such as friction, surface roughness, speed, and others. Ray W.Murphy et al [5] in their report concluded that the braking efficiency of trucks and can be improved by careful distribution of braking effort among the axles of the vehicle. Mr Songwut Mongkonlerdmanee [6] in his thesis concluded that to achieve maximum brake efficiency, vehicle geometry and real friction coefficient should be considered to design the brake proportion on each axle and the deceleration and braking distance on the front axle was better than those on the other axles because of the additional vertical load from the dynamic transfer. Muhammad najib bin abdulhamid[7] conducted the experimental analysis on drum brake and FEA analysis and concluded that improved material performs better. Kang and Cho [8] investigated thermal deformation and stress analysis of brakes by finite element method for ventilated disk and solid disk. By comparing the result of maximum temperature in the braking process, the ventilated disk showed a lower temperature than the solid disk. The effect of temperature increase and decrease, depending on the vent area generated in the flange part of the disk. Analysis of design parameter effects on vibration modes of a motorcycle drum brake and brake shoe using the finite element method were also carried out. They reported that the drum brake had 42 mode shapes in the frequency range of 100 Hz to 12 khz. Most of the mode shapes occurred in pair (repeated

3 root). The brake shoe wasfound to have 10 modes shapes in the frequency range analyzed. 3.PROBLEM STATEMENT 3.0 problem statement:drum Brake and Drum Brake Pad are connected on the wheels of automobile for the braking of the vehicle on road. The drum brake and brake pad under goes several rough conditions on road different types of loads and temperatures will be acting on the brakes. The brakes are surely essential for the effective stopping of the vehicle. Here in this project we are taking the load condition as 1.5Mpa pressure on the face of the drum Brake and also the Drum brake pad. We are using three different materials i.e aluminium alloy, carbon steel and aluminium metal matrix composite. Doing the analysis on three different materials using the load condition we will find which is the best appropriate material for use. Also when the brake is applied due to the friction between the drum and the brake pad certain heat is distributed and released. Here we consider the thermal conditions to be as 90deg temperature and 22deg convection. Thus applying all the load and thermal conditions for three different materials Drum Brake and BrakePad we conclude the best desirable materials. 3.1 objectives of project The objectives of the project are as follows (i) To develop structural modeling of Drum Brake and BrakePad. (ii) To perform finite element analysis of Drum Brake and Brake Pad. (iii) Suitable material study. (iv) Study of load and Thermal factors. (v) Study of stress, strain deformation, temperature and heat flux induced in the Drum Brake and Brake Pad. (vi) To develop structural optimization model of connecting rod 4. DESIGNING OF ADRUM BRAKESBY USING SOLID WORKS 4.1 Introduction To Solidworks : Solidworks mechanical design automation software is a feature-based, parametric solid modeling design tool which advantage of the easy to learn windows TM graphical user interface. We can create fully associate 3-D solid models with or without while utilizing automatic or user defined relations to capture design intent. Parameters refer to constraints whose values determine the shape or geometry of the model or assembly. Parameters can be either numeric parameters, such as line lengths or circle diameters, or geometric parameters, such as tangent, parallel, concentric, horizontal or vertical, etc. Numeric parameters can be associated with each other through the use of relations, which allow them to capture design intent A Solid Works model consists of parts, assemblies, and drawings. Typically, we begin with a sketch, create a base feature, and then add more features to the model. (One can also begin with an imported surface or solid geometry). We are free to refine our design by adding, changing, or reordering features Design procedure of Drum Brakes For designing the Drum Brakes the following procedure has to be follow

4 Making Circular Pattern 4.3 Design procedure of Drum Brake Pad For designing the Drum Brakes the following procedure has to be follow Dimensions of Drum Brake Brake shoe lining Sketch and Extrude Sketch & Revolve Make Shell.Brake Pad Extrude Cut All Views of Brake Pad

5 5. ANALYSIS DEFINATION &STEPS: The steps needed to perform an analysis depend on the study type. You complete a study by performing the following steps: Create a study defining its analysis type and options. If needed, define parameters of your study. A parameter can be a model dimension, material property, force value, or any other input. Define material properties. Specify restraints and loads. The program automatically creates a mixed mesh when different geometries (solid, shell, structural members etc.) exist in the model. Define component contact and contact sets. Mesh the model to divide the model into many small pieces called elements. Fatigue and optimization studies use the meshes in referenced studies. Run the study. View results. 5.1 Analysis on Drum Brakes by using ansys 14.5 work bench software The analysis of Drum brake and Brake pad models are carried out using ANSYS software usingfiniteelement Method. Firstly the model files prepare in the SOLIDWORKS SOFTWARE. Then are exported to ANSYS software as an IGES files as shown in figure Figure5.1 structural analysis of Drum Brake Figure5.2 structural analysis of Brake Pad 5.2 Materials and their properties 5.3 Load & fixed support Fixed support

6 It's done with a variety of tools & options available in the software. The results are calculated bysolving the relevant governing equations numerically at each of the nodes of themesh. The governing equations are almost always partial differential equations, and Finite element method is used to find solutions to such equations. The pattern and relative positioning of the nodes also affect the solution, the computational efficiency & time. Load Load at 1.5MPA Mesh Type: Tetrahedral No. of nodes: No. of elements: STRUCTRUALANALYSISRESULTS FOR DRUM BRAKE 6.1 Material: Aluminium Alloy Maximum Stress 5.3 Meshing Meshing is probably the most important part in any of the computer simulations, because it can show drastic changes in results you get. Meshing means you create a mesh of some grid-points called 'nodes. Total Deformation

7 Maximum Strain 6.3 Material: Aluminium Metal Matrix Maximum Stress 6.2 Material: Carbon Steel Maximum Stress Total Deformation Maximum Strain Total Deformation Maximum Strain 7. STRUCTRUALANALYSIS RESULTS FOR DRUM BRAKE PAD 7.1Material:Aluminium Alloy Stress

8 Total Deformation Maximum Strain Maximum Strain 7.3Material:Aluminium Metal Matrix Stress 7.2Material:Carbon Steel Stress Total Deformation Total Deformation Maximum Strain

9 8. THERMAL ANALYSIS RESULTS FOR DRUM BRAKE Temperature 90 c 8.2 Material: Carbon Steel Temperature Distribution Convection 22deg Heat Flux 8.1 Material: Aluminium Alloy Temperature Distribution 8.3 Material: Aluminium Metal Matrix TemperatureDistribution Heat Flux Heat Flux

10 9. THERMAL ANALYSIS RESULTS FOR DRUM BRAKE PAD Temperature 90 c 9.2 Material: Carbon Steel Temperature Distribution Heat Flux Convection 22 deg 9.3 Material: Aluminium Metal Matrix Temperature Distribution 9.1 Material: Aluminium Alloy Temperature Distribution Heat Flux Heat Flux

11 RESULT TABLE Results for Drum Brake For comparisons of the results obtained From the static analysis result tables it is concluded that 42CrMo4 show least stress and least deformation & strain value on same static load condition. Results for Brake Pad From the Modal analysis result tables it is concluded that 42CrMo4 shows Less deformation results for given frequency. Hence for both Structural and Modal Analysis 42CrMo4 (Special Alloy Steel) it is best suitable material for connecting rod. CONCLUSION Modeling and analysis of drum brakes and drum brake pads is done.

12 Modeling of drum brake and drum brake pads are done in solid works 2016 design software. Thus both files are saved as igs to import into ansys workbench Structural and thermal analysis is carried on drum brake and drum brake pads in ansys workbench First structural analysis of pressure of 1.5 Mpa is applied with three different materials such as aluminum alloy, Carbon Steel, aluminum Metal matrix. Maximum stress, deformation, strain, Temperature and Heat flux are found and tabulated. Next steady state thermal analysis of drum brake with three different materials aluminum alloy, Carbon Steel, aluminum Metal matrix at 90 0 c temperature and 22 0 c ambient temperature of convection is applied Temperature distribution and total heat flux are obtained and tabulated. Thus the stress, strain, shear stress and total deformations values are obtained and tabulated. From result we can conclude that beside general material, aluminum metal matrix (ks1275) which is economically less cost and less weight ratio gives nearly same stress and deformation value in static analysis and giving good thermal distribution value so it can also use as the material for drum brake beside general materials. Thus the modeling and analysis of drum brake is done with different materials at different boundary conditions. REFERENCES [1]. Anup Kumar and R. saharish. Structural and Thermal Analysis of Brake Drum. Middle East Journal of Scientific Research Vol20. (8). IDOSI Publication. Pp [2]. Brake Drum. Available at en.wikipedia.org/wiki/drum_brake. Cited March [3]. Frank Kreith. Mechanical Engineerimg Handle Book. Boca Raton: CRC Press LLC. Pp [4]. Daniel Dannelley, John Baker, Clark K. Midkeff, Robert P. Taylor, Keith A. Woodburry. Enhancement of Extended Surface Heat Transfer Using Fractal-like Geometry. Department of mechanical Engineering, Graduate School of the University of Alabama. Pp [5]. Fred Puhn. Brake Handbook. 2rd edition.hp Books Pp4, [6]. Giri N.K. Automobile Technology. Sixth edition (reprint). Khanna Publisher. Pp [7]. James Carvill. Mechanical Engineer s Data Handbook. First Edition. Butterworth Heinemann Publication. Pp [8]. Karim Nice. How Drum Brakes Works. Available at 1.htm. cited March 2015 [9]. Kicreyco Brake Drum Catalog. Kic Holding IncPp Available at Cited April 2015.

13 [10]. Narang G.B.S. Automobile Engineering. First Edition. Kahanna Publisher. Pp [11]. PrabalTalukdar Design of Heat Sink (1-3). Thermal System simulation (2-0-2), Department of mechanical Engineering, IIT Delhi. AUTHORS 1.DVSRBM SUBRAMANYAM Associate Professor of Mechanical Engineering, College name:nalanda institute of engineeringand technology,village:kantepudi Mandal:sattenpalli, Dist:guntur A.P, India,Pin: L.SRAVANI Department ofmechanical Engineering, College name:nalanda institute of engineeringand technology, Village:kantepudi Mandal:sattenpalli, Dist:guntur A.P, India,Pin: id: