Snubber Development I-Advanced Physics-Project Presentation, Slides of Physics

Download Snubber Development I-Advanced Physics-Project Presentation and more Slides Physics in PDF only on Docsity!

Contents

2

Introduction

Strategy

Operation of Mechanical Snubber

1

4

7 Summary and Conclusions

2 Snubber Development

3 Types of Snubber

5 Modification of the Test Rig

6 Designing of the Main Components

Snubber Development

 Snubbers traces its history back to 1955-1960 when focus were given to the fact that to utilize the huge amount of energy with in fissile elements for peaceful purposes

 There is a tremendous amount of heat with in the core of nuclear reactor

 To remove this heat and make possible the safe operation of the plant pumps having 96000 gallons per minute discharge are used

 Due to this high discharge vibration are produced in the primary loop, Shock loads are also induced as a result of earth quack

 So in order to protect the equipments from these tremendous amount disturbing forces snubber were developed 4

Snubber Modes of Operation

5

In the active mode of snubber mechanism is engaged and the snubber limits the acceleration to a low threshold value

2 Modes of

Operation

In the passive mode motion caused by thermal loads ,and the resisting mechanism is disengaged and the snubber offers very low resistance

Passive Mode

Active Mode

Mechanical Snubber Operation

7

Exploded View of Mechanical

Initial Model of Test Rig

10

Working Cycle

11

Modified Model of Test Rig

13

Exploded View of the Test Rig

14

Designing of Hydraulic Cylinder

16

Results Table for Different Diameters

Sr No: (mm) (^) (mm)

σ r

(KPa)

σ t

(KPa)

σ L

(KPa)

Fracture Pressure (KPa)

F.S

3 88.9^ 58.42^ 683.43^ -279.57^ 201.93^ 520.55^^14

22

Do Di

The results for the cylinder shown in the 3rd^ row is selected because

 Maximum Fracture Pressure  Availability in Market  Low Cost

Tresca Failure Theory

 According to Tresca Failure Theory

 = Effective Stresses

 = Stress in Axial Direction

 = Bending Stresses

 = Shear Stresses

 = Material (Cast Iron) Yield Strength=130 MPa

By putting the values we get Factor of Safety

FS= 10

Since it is greater than 1 so the design is safe

29

2 2 2 y eff x^ y^ x^ y^ xy

S σ = σ +σ +σ σ +3×τ FS



σeff σx σy xy Sy

Thickness of Cylinder Cover Plate

 The thickness of the cylinder head is calculated by

Where

 t = Thickness of the Cylinder Plate  Do = Diameter of the cylinder rod  D = Outer diameter of the cylinder  F = Load transmitted by the cylinder  = Tensile Stresses in the material

30

o t

0.67 D F t 3 1 D

     

    

t

6

t 3 1

t 0.0350 m

t 35 mm