STRUCTURAL ANALYSIS OF A BRAKE DISC

ByA. Pravalika (12N31A2101)

Vedprakash Arya (12N31A2105)B. Ravi Kumar(12N31A2106)B. Prudhvi Raj (12N31A2110)

Under the guidance ofMr. SHAILESH BABU

Asst. ProfessorDepartment of Aeronautical Engineering, MRCET.

ABSTRACTThe present investigation is aimed to study the given disc

brake rotor of its stability and rigidity, for this structural analysis is carried out on a given disc brake rotor. In this project the specified dimensions of the disc brake are taken for modeling in the software ANSYS. Static analysis was carried out on the disc brake considering the significant support structures with respective of disc. In analysis part, the finite element of portion of the disc is created, appropriate boundary conditions are applied, material properties are given and loads are applied as per its design. The resultant deformation and stresses obtained are reported and discussed.

INTRODUCTION

❑ The disc brake is a device used for slowing or stopping the

rotation of the wheel.

❑ A brake is usually made of cast iron or ceramic composites

include Carbon, Aluminium, Kevlar and Silica.

BRAKING REQUIRMENTS❑ The brakes must be strong enough to stop the vehicle with in

a minimum distance.

❑ The brakes must have well anti fade characteristics i.e. their

effectiveness should not decrease with constant prolonged

application.

“The principle used is the applied force (pressure) acts on

the brake pads, which comes into contact with the moving disc.

At this point of time due to friction the relative motion is

constrained.”

PRINCIPLE

WORKING

When the brakes are applied, hydraulically actuated

pistons move the friction pads in to contact with the disc,

applying equal and opposite forces.

DISC BRAKE COMPONENTS

APPLICATIONS

❑ MOTORCYCLES

❑ Bicycles

❑ Cars

❑ OTHER VEHICLES

ADVANTAGES

❑ Good braking at both low and high speeds

❑ Light weight

❑ Anti-skid protection

❑ Simple installation

DISADVANTAGES

❑ It is expensive compare to drum brake.

❑ If any air remains in disk brake system, it can cause accident as the brake will not work effectively.

❑ Disk brake assembly has more moving parts and much complex than drum brake.

PROCEDUREDisc Brake has been modelled with the help of

ANSYS v16.0 software. The Orthographic and Solid

Model of Disc Brake is shown in the figures. The following

is the list of steps that are used to create the required

model.

CONSIDERATIONSFollowing Considerations are done for our

project.

❑ Young’s modulus=2x105N/m2

❑ Poissions ratio=0.3

❑ Pressure=500N/m2

❑ Density=7800Kg/m3

Model generation❑ STEP 1: From the Main menu select Preferences. Select

structural and press OK.

❑ STEP 2: From the main menu select Pre-processor.

Element type → Add / edit/Delete → Add →SOLID-10 node

187 → Apply → Close.

Material properties → material models → Structural →

Linear → Elastic → Isotropic–

Young’s Modulus = 2x105N/m2.

Poissions ratio = 0.3;

Density =7800Kg/m3.

❑ STEP 3: From the main menu select Pre-

processor.

Modelling → Create→ Key points → In Active

CS→ enter following points→ Apply→ for last

key point value press Ok.

S. No. Key point

1 (0,0,0)

2 (30,0,0)

3 (30,-12,0)

4 (70,0,0)

5 (58,-12,0)

6 (58,-60,0)

7 (70,-36,0)

8 (131,-36,0)

9 (131,-60,0)

10 (0,-10,0)

Fig. Table for keypoints.

❑ STEP 4: From the main menu select Pre-processor.

Modelling: Create → lines → Straight lines → Select two

points through which a line has to be created similarly

create lines through the points

2-4, 4-7, 7-8, 8-9, 6-5, 5-3, 3-2.

❑ STEP 5: From the main menu select Pre-processor.

Fig. Initial modelling

Modelling: Create → Areas → Arbitrary → by lines → select all lines → apply → OK

❑ STEP 6: From the main menu select Pre-processor.Modelling: Operate → Extrude →About axis → Arc length in degrees=360;

Fig. Disc Brake model

MESHING OF THE MODELMeshing is done on the Disc Brake for easy solving and accurate results in ANSYS.

❑ Meshing the Geometry. From themain menu select Pre-processor.

Meshing → mesh tool→ element attributes-global→mesh-volumes→ mesh. Select all volumes→ Click OK.

Fig. Meshed model

APPLYING BOUNDARY CONDITIONS❑ STEP 1: Defining loads at the Areas.

Solution → Define Loads → Apply→Structural

→Displacement→ On Areas Left circle area –ALL DOF

arrested.

❑ STEP 2: Solution → Define

loads → Apply →Structural

→Pressure→On Areas

Fig. Arresting disc

Select the area where shaft is to be placed – Apply pressure = 500 N/m2.

❑ Solution: Solution → Solve → Current LS → OK → Solution is done → close.

Fig. Applying loads at inner area.

RESULTS

Fig. Von Mises stresses. Fig. Nodal solution of a disc brake in X direction

Fig.Nodal solution of a disc brake in Y direction

Fig.Nodal solution of a disc brake in Z direction

OBTAINED VALUESS. N.  VALUES NODAL SOLUTION ABOUT AXIS PRINCIPLE STRESSES

 X  Y  Z  1st  2nd  3rd

 1 DMX (m)  .1667 .101E-05 .101E-05 .101E-05  .101E-05 .101E-05

 2  SMN (N/m2) -510.01 -1097.03  -3048.67 -219.652 -337.84 -3057.05

 3  SMX (N/m2)  781016 885.312  4722.35 4797.16  758.736 38.2384

S. N.  VALUES  VOLUME CONTOURS SHEAR STRESSES

 XY XZ  YZ

1  DMX (m) 0.101E-05 .101E-05  .101E-05  .101E-05

2 SMN (N/m2)  4.90814  -2236.598 -3836.48  -258.463

3 SMX (N/m2)  2209.91  274.497 3703.08  230.23

Table: 1

Table: 2

CONCLUSION❑ The inner area of the disc where shaft is to be placed will be

affected more than any other part of the disc.

❑ On analysing the defections and stresses obtained as a result of given pressure.

❑ The Cast iron disc which is considered here can withstand for this pressure.

❑ Thus the further experiment can be conducted with addition of pressure and can be analysed.

FUTURE SCOPE❑ Since the brake disk design is safe based on the strength and

rigidity criteria. But the stresses observed in the results are not adequate with the practical scenarios.

❑ To improve the performance of the disc brake, material and design, modifications can be made on structural design. Also, a model with ventilated area which can withstand both structural and thermal variations, is suggested.

…THANK YOU…