Final Report BSp

A PROJECT REPORT ON

“DESIGN OF A LIFTING ARRANGEMENT FOR

FABRICATION &ERECTION OF WALKWAYS ON

ROOFTOP OF FOUNDRY SHOP”

PREPARED BY : GUIDED BY :

ARPIT DUBEY (JEC JABALPUR, MP.) Mr.K.K THAKUR

AGM FOUNDRY SHOP

ACKNOWLEDGMENT

Our first experience of project has been successful, we are thankful to the support of

staff of Bhilai Steel Plant with immense gratitude. We wish to acknowledge all of

them. However, we wish to make special mention of the following.

First of all we are thankful to our project guide Mr.K.K.THAKUR under whose

guideline we are able to complete our project. We are wholeheartedly thankful to him

for giving us his valuable time, attention and for providing us a systematic way for

completing our project in time.

We are wholeheartedly thankful to him for giving us his valuable time and

attention and for providing us a systematic way for completing our project in time.

We are also very thankful to Human Resource Department and Foundry and Pattern

Department for giving us the opportunity to conduct this project in Bhilai Steel Plant.

DECLARATION

I hereby declare that the project work entitled " DESIGN OF A

LIFTING ARRANGEMENT FOR FABRICATION &ERECTION OF

WALKWAYS ON ROOFTOP OF FOUNDRY SHOP " is an authentic

record of my own work carried out at the Foundry & Pattern Shop

of Bhilai Steel Plant as requirement of Four Weeks project based

training of B.E INDUSTRIAL &PRODUCTION Engg. Dept., JEC

JABALPUR, MADHYA PRADESH under the guidance of

Mr.K.K.THAKUR, from 01th June 2015 to28th June 2015.

Date:........................ (Signature of Student)

ARPIT DUBEY

CERTIFICATE

This is to certify that Project Report entitled “DESIGN OF A LIFTING

ARRANGEMENT FOR FABRICATION &ERECTION OF WALKWAYS

ON ROOFTOP OF FOUNDRY SHOP” which is submitted by Mr. ARPIT

DUBEY, JEC JABALPUR,MADHYA PRADESH in partial fulfilment of the

requirement for the award of degree B.E. in INDUSTRIAL & PRODUCTION

Engineering to is a record of the candidate’s own work carried out by him/her under

my supervision. The matter embodied in this project is original and has not been

submitted for the award of any other degree.

INDEX

S.NO TOPIC PAGE NO.

1. LIST OF ABBREVIATIONS

USED

8

2. BHILAI STEEL PLANT

9-15

3. HUMAN PROFILE 16

4. FOUNDRY & PATTERN SHOP

17-25

5. PROBLEM SPECIFICATION

26

6. LIFTING SYSTEMS 27

7. MECHANISM USED 28-29

8. VALIDATION OF DESIGN

30-40

1) LIST OF ABBREVIATIONS USED

σt Permissible tensile stress

σc Permissible compressive stress

σb Permissible bending stress

τ Permissible shear stress

b Width

L Length

d0 Outer diameter of pipe

di Inner diameter of pipe

Mb Bending moment

e Eccentricity

P Load applied

Mt Torsional moment

D Diameter of pipe

2)BHILAI STEEL PLANT

INTRODUCTION

Bhilai Steel Plant, located in Bhilai, Chhattisgarh and it is India's only

producer of steel rails, and is a major producer of steel plates and

structural components. It is a symbol of Indo-Soviet techno-economic

collaboration, is one of the first three integrated steel plants set up by

Government of India to build up a sound base for the industrial growth

of the country. The agreement for setting up the plant with capacity of 1

MT of Ingot steel was signed between the Government of U.S.S.R and

India on 2nd February, 1955 and after a short period of 4 years, India

entered the main stream of the steel producers with the commissioning

of its first Blast Furnace on 4th February, 1959 by the President of India,

Dr. Rajendra Prasad. Commissioning of all the units of 1 MT stage was

completed in 1961. A dream came true-the massive rocks from the virgin

terrains of Rajhara Mines(90 km) were converted into valuable iron &

steel.

In the initial phase the plant had to face many teething problems, mostly

unknown to the workforce at the time, but by meticulous efforts and team

spirit, these problems were surmounted and the rated capacity production

was achieved only within a year of integrated operation of the plant.

Thereafter, the plant was expanded to 2.5 MT capacity per year, and then

to 4 MT of crude steel per year, with Soviet assistance.

All the units of the plant have been laid out in sequential formation

according to technological inter-relationship so as to ensure

uninterrupted flow of in-process materials like Coke, Sinter, Molten Iron,

Hot Ingots, as well as disposal of metallurgical wastages and slag etc.,

minimizing the length of various inter-plant communications, utilities

and services.

BSP is the sole manufacturer of rails and producer of the widest and

heaviest plates in India. Bhilai specializes in the high strength UTS 90

rails, high tensile and boiler quality plates, TMT bars, and electrode

quality wire rods. It is a major exporter of steel products with over 70%

of total exports from the Steel Authority of India Limited being from

Bhilai. The distinction of being the first integrated steel plant with all

major production units and marketable products covered under ISO

9002 Quality Certification belongs to BSP. This includes manufacture of

blast furnace coke and coal chemicals, production of hot metal and pig

iron, steel making through twin hearth and basic oxygen processes,

manufacture of steel slabs and blooms by continuous casting, and

production of hot rolled steel blooms, billets and rails, structural, plates,

steel sections and wire rods.

The plant's Quality Assurance System has subsequently been awarded

ISO 9001:2000. Not content with the Quality Assurance system for

production processes, Bhilai has one in for ISO 14001 certification for its

Environment Management System and its Dalli Mines(96 km). Besides

environment-friendly technology like Coal Dust Injection System in the

Blast Furnaces, de-dusting units and electrostatic precipitators in other

units, BSP has continued a vigorous afforestation drive, planting trees

each year averaging an impressive 1000 trees per day in the steel

township and mines.

A leader in terms of profitability, productivity and energy conservation,

BSP has maintained growth despite recent difficult market conditions.

Bhilai is the only steel plant to have been awarded the Prime Minister's

Trophy for the best integrated steel plant in the country eleven times.

Bhilai Steel Plant, today, is a panorama of sky-scraping chimneys and

blazing furnaces as a modern integrated steel plant, working round the

clock, to produce steel for the nation. Bhilai has its own captive mines

spread over 10929.80 acres. We get our iron ore from Rajhara group of

mines, 90 kms south-west of Bhilai. Limestone requirements are met by

Nandini mines, 25 kms north of Bhilai and dolomite comes from Hirri in

Bilaspur district, 150 kms east of the plant. To meet the future

requirement of iron ore, another mining site Rowghat, situated about 100

km south of Rajhara, is being developed; as the ore reserves at Rajhara

are depleting.

Bhilai expanded its production capacity in two phases - first to 2.5 MT

which was completed on Sept. 1, 1967 and then on to 4 MT which was

completed in the year 1988. The plant now consists of ten coke oven

batteries. Six of them are 4.4 metres tall. The 7 metre tall fully

automated Batteries No 9 & 10 are among the most modern in India of

Bhilai's seven blast furnaces, three are of 1033 cu. metre capacity each,

three of 1719 cu. metre and one is 2350 cu. metre capacity. 2.8 MT Hot

Metals can be made from each blast furnaces per year. Most of them

have been modernised incorporating state-of-the-art technology.

Steel is made through 4 twin hearth furnaces in Steel Melting Shop I as

well as through LD Convertor -continuous Casting route in SMS II. Steel

grades conforming to various national and international specifications

are produced in both the melting shops. Production of cleaner steel is

ensured by flame enrichment and oxygen blowing in SMS I while

secondary refining in Vacuum Arc Degassing ensures homogenous steel

chemistry in SMS II. Also in SMS II is a 130 T capacity RH (Ruhshati

Heraus) Degassing Unit, installed mainly to remove hydrogen from rail

steel and Ladle Furnace to meet present and future requirements of

quality steel. Bhilai is capable of providing the cleanest and finest grades

of steel.

The rolling mill complex consists of the Blooming & Billet Mill, Rail &

Structural Mill, Merchant Mill, Wire Rod Mill and also a most modern

Plate Mill. While input to the BBM and subsequently to Merchant Mill

and Wire Rod Mill comes from the Twin Hearth Furnaces, the Rail &

Structural Mill and Plate mill roll long and flat products respectively from

continuously cast blooms and slabs only. The total length of rails rolled

at Bhilai so far is sufficient to encircle the globe more than 9.9 times.

To back this up, we have the Ore Handling Plant, three Sintering Plants –

of which one is most modern, two captive Power Plants with a generating

capacity of 110 MW, two Oxygen Plants, Engineering Shops, Machine

Shops and a host of other supporting agencies giving Bhilai a lot of self-

sufficiency in fulfilling the rigorous demands of an integrated steel plant.

Power Plant No.2 of 74 MW capacity has been divested to a 50:50

SAIL/NTPC joint venture company.

The Annual Production Plan for 2015-2016 includes, 5570000 T of Hot

Metal Pig Iron 5300000 T Total Crude Steel 4700000 T Total Saleable

Steel

The plant has undertaken massive modernization and expansion plan to

produce 7.5 MT of hot metal after the setting up of SMS III which is

under construction currently.

Bhilai Steel Plant-SAIL used to spent 2% of their net profit for the

development of nearby places. 136 Villages in 16km periphery ofBhilai

Steel Plant is covered by BSP for construction of schools, roads, parks,

teaching/training aids, etc. The net profit of BSP-SAIL for the year 2013-

2014 was 2084 Crores.

BSP makes longest rails in the world which is having a length of 260

metres. Now Research is going on developing of rails with 520 metres

length.

A leader in terms of profitability, productivity and energy conservation,

BSP has maintained growth despite recent difficult market conditions. A

significant reason for BSP's performance is adherence to quality

management systems in different fields: Bhilai has become the first

public sector organization to have been awarded all the four

certifications of ISO 9001 for quality, ISO 14001 for, environmental

management system for plants and mines, OHSAS 18000 for safety and

health and SA 8000 for social accountability.

3) HUMAN PROFILE

More than the machinery and processes, it is the men i.e. the engineers,

technicians, skilled and unskilled workers behind them that constitute

the flesh and blood of this steel plant. Bhilai at present has 3729

executive and 23118 non-executive persons to run this pulsating giant.

The culture which has today become the hallmark of Bhilai is a result

oriented approach to work. It is their effective and co-operative working

relationship nurtured in a spirit of dedication and enthusiasm that has

shaped Bhilai's image today.

Adjoining the plant, a modern township - Bhilai Nagar, having the

spaciousness of a village and the cleanliness of a modern town is spread

– over in 17 self sufficient sectors with schools, markets, parks and other

facilities. Free Medical aid is given to all the employees and their

dependents through a network of health centres, dispensaries and

hospitals. Medical facilities are extended to retired employees & their

spouses also. The Education Department runs a number of higher

secondary, middle, primary, and pre-primary schools in Bhilai and also in

the mines townships at Rajhara, Nandini and Hirri.

4)FOUNDRY & PATTERN SHOP

Introduction: There are many shops in the Bhilai Steel Plant which supports the basic

process carried out for the manufacture of steel and its products. One of

them is the Foundry & Pattern Shop. A Foundry is a factory that

produces metal castings. It is a place of making moulds, cores and

manufacturing metal castings also fettling/finishing of castings and sand

reclamation is done economically and carefully. Metals are cast into

shapes by melting them into a liquid, pouring the metal in a mould, and

removing the mould material or casting after the metal has solidified as it

cools. The most common metals processed are aluminium and cast iron.

However, other metals such as bronze, steel, magnesium, copper, tin, and

zinc, are also used to produce castings in foundries.

Foundry & Pattern shop is an important Engineering Shop, set up to meet

the requirement of various ferrous and non-ferrous castings and cast

blanks required for the plant and other Engineering Shops especially

machine shops, for manufacture of spares. It comprises two major parts,

the Pattern Shop and the Foundry Shop.

PATTERN SHOPThe pattern shop is designed to produce patterns for foundry needs. The

annual output is rated at 220 Cu. meters. The shop works in G shift. It is

equipped with modern set of working machine tools. Handling of heavy

patterns at the shop and storage is carried out by overhead travelling

crane operated from floor level. The patterns are painted according to a

code, ticked, labelled and stored, to enable the patterns to be issued to

foundry as and when required, according to a well-laid out procedure.

The pattern storage room is protected against any fire hazards.

FOUNDRY SHOP

The foundry shop is laid out in five bays, each of length 270 meters.

Various

types of castings and their usage is as follows :

Iron Castings : ( Capacity 79000 T/year)

i) Spare parts for machines / equipments.

ii) Ingot moulds.

iii) Bottom Stools.

Steel Castings : ( Capacity 6500 T/ year)

i) Spare parts for machines / equipments.

ii) Twin hearth-charging boxes.

iii) Skull cracker balls.

iv) Spares for Mould bogie.

v) Ladle covers for SMS, Lip ring for CCS.

vi) Pig casting moulds.

vii) Alloy steel Ingots.

Non - Ferrous Castings : ( Capacity 515 T/ Year)

i) Bushings, slide blocks for machines/ equipments.

ii) Monkey for BF & Hollow shaft for SMS.

iii) L.N. body & covers.

iv) Al. Cubes & Al. Shots for SMS-I & SMS-II.

Main Sections of Foundry Shop :

1) Charging and Moulding Material Store : The charging and

moulding material storage is designed to hold 15 days supply of all raw

material used in foundry. The storage bay is served by overhead

travelling cranes with removable magnets. With the help of electric grabs,

all the raw materials are stored in bins & bunkers.

2) Sand Preparation Section :

In this section, preparation of moulding sands and core sand mixture for

all types of castings is done. The raw silica sand is received from

Sambalpur and Allahabad. Quartzite sand is supplied by Crushing Plant.

The new sand, if wet, is dried in a rotary dryer in which sand is heated to

200-250 deg.C. The dried sand is fed in the feeding hoppers, over the

sand mixers of 20 cu.m/hr capacity. In the sand mixer; various moulding

materials like fire clay, bentonite, molasses, saw dust etc. are added and

mixed. The sand so prepared is distributed by the system of conveyor

belts throughout the cast-iron, steel and core section. 130 T of mixed sand

is produced by sand mixers for preparing different types of sand mixtures

for core section (about 5 T per day).

3) Iron Foundry :

The Iron foundry can be divided in to the following sub-sections.

i) Cast Iron section.

ii) Mixer section

iii) Moulding section

iv) Ingot Moulds

v) Mould drying chambers.

The estimated annual requirement of the metal is about 1,00,000 tons and

the

daily requirements is 270 tons. The moulding section prepares moulds for

all types of castings required under the schedule or special work requiring

upto 30 tons liquid metal. The Ingot Mould section produces the Ingot

Moulds required by the plant. Each Ingot Mould weights 8.8. T or 9.3 T

and the daily production of Ingot Moulds are 17 nos. on average. Ingot

Moulds are rammed on two 30 tones jolting machines in the Ingot Mould

section.

The Ingot Mould section produces the Ingot Moulds required by the

plant. Each Ingot Mould weights 8.8. T or 9.3 T and the daily production

of Ingot Moulds are 17 nos. on average. Ingot Moulds are rammed on two

30 tones jolting machines in the Ingot Mould section.

Top box is prepared for using at top of Ingot Mould for pouring. The

mould drying chambers are used for drying the moulds in the chamber

type drying ovens at the temperature of 300-350 degree cel. There are 6

drying ovens. The 4 drying ovens are of 130 Cu.m. capacity and the other

2 of 60 cu.m. capacity for drying small castings. These ovens have been

provided with an arrangement for the re-circulation of the products of

combustion. Coke oven gas is used for heating purpose.

Moulding of Bottom Stools in Cast Iron section :

Apart from rammed moulds with bottom chills, "Chill bottom stools"

mouldings are done by chill mould i.e. in the C.I. section. A better type of

bottom stools are known as "Chill bottom Stools"- these give more life,

and are of better quality.

The 30 ton jolting machine in the CI section: At present this is being used

for making self core of charging boxes.

The Iron foundry is serviced by overhead travelling cranes (75 T, 50 T,

30 T) and cantilever cranes (5T). This section of the foundry is also

equipped with ladle preheating burners. For the inter bay transfer of

materials (castings, moulding boxes, containers etc.) there are 4 transfer

cars of 50T capacity each.

4) Steel Foundry

This section is located in line with the Iron casting section. It is divided

into the following sub-sections:

I) Steel Melting Section

II) Moulding Section.

The steel melting section is provided with two 5 T direct arc furnaces

with 3-

phase supply. Melting and moulding section operate in 3 shifts on parallel

schedule. The furnaces are lined with mangnesite on the silica bricks on

the roof, Water cooling is provided at electrode holders, roofing,

economisers, door frame and tap hole arc. To charge the furnace its roof

is lifted and shell is rolled out. A pointer attached to the body of the

furnace indicates the amount of forward fill during the slagging and

tapping time. 3 nos of 300 mm diameter electrodes passing through the

roof, supply the electrical energy to the furnace. Transformer capacity is

28 KVA. Heat time varies from 2-2.30 hrs. for plain carbon steel and 3 -3

1/2 hrs. for alloys steels. Castings around 10 T. are made by running the

furnaces simultaneously.

The moulding section operates in 3 shifts. Preparation of moulds is

carried out on the foundry floor as well as, for moulding the PCMS (pig

castings moulds), in boxes. Two 2.5 T moulding machines are also

provided in this section. There are two cranes one of 30 T. one of 15 T

and one cantilever crane of 15 T capacity. The mould drying is carried

out in mould drying chamber of 60 cu. meters capacity located in this

section. Some moulds are also dried in bigger ovens in IM section. The

section is provided with two 50 T. transfer cars to bring charge materials

and to despatch castings to fettling section.

5) Non - Ferrous foundry

The Non-ferrous foundry is meant to produce liners, bearings, slide

blocks, bushes and other small castings of different types from brass and

bronze. Besides 1 Ton Induction furnace two indirect arc electric furnaces

are for melting nonferrous metals. These are of 0.5 Ton capacity and are

scheduled to produces 515 Tonnes of nonferrous metal. The furnace is of

cylindrical shape having two electrodes. The furnace is rocking type lined

with high alumina fire blocks. Moulds are dried in 11 cu.m. oven.

Aluminium Shots and Cubes section consists of 3 Al. melting and

pouring units and 3 melting crucibles for Al. Cube making.

6) Fettling section :

This section is equipped with the following equipment

I) Knock-Out Machine :

After solidification of the metal in the mould, the moulds are placed on

the 20 T knockout machine for the separation of mould box, sand and the

casting. From the knock-out machine., the casting is removed and if

necessary washed in the hydraulic chamber.

II) Hydro cleaning chambers : 2 nos.

The hydro cleaning chamber is equipped with central rotating table and

jet of

water operating on high pressure of 150 atm. When the casting is placed

on the table with the water jets hitting the casting, all sand is removed.

Two such chambers are provided in this section.

III) Milling Machines : 2 nos.

For machining the bottom of Ingot Moulds, two mould milling machines

have been provided. Each machine has provision of mounting two ingots

at a time for continuous milling.

7) Cranes :

There are in all 24 E.O.T cranes, including the crane in the new bay

(towards SMS stripper yard)

Additional facility of 4 mt. stage :

1. The Open DE bay in the existing shop has been covered over a length

of 71 meters from column row 20 to 32 in order to provide additional

space for

production of steel castings. A small sand preparation unit, a drying oven

of

capacity 100 cu. m. and a paint mixer have been installed in this area.

2. A fully covered new bay measuring 12 x 168 m with 10 T EOT crane

has been constructed towards steel melting shop's stripper yard for storing

moulding tackles and moulding materials. This bay connecting with the

existing AB bay by extending the 50 T transfer car line form BC Bay.

3. 1 Ton capacity induction furnaces 2 nos. installed in Non-ferrous

section, for non-ferrous & alloy cast iron melting : commissioned in Dec.

1995.

4.4 Critical Equipments in Foundry Shop in BSP:

Name of the Equipment Capacity Location

Hot Metal Mixture 2 in no.100 tonnes capacity

each

It is in Metal Mixer Section.

Electric Arc Furnace (Steel formation)

2 in no.Inception capacity 5

tonnes each.

Electric Arc Furnaces Section.

Dual Induction Furnace 1 tonne capacity It is in non-ferrous section.

Continuous Sand Mixer 2 in no. &30 T/hr of sand mixing capacity.It can lift 9 tonnes of re-cleaned or dry sand into

Hopper.

It is in Sand mixer section

4.5Types of Hazards present in Foundry & Pattern Shop:

Type EFFECT

Physical Heat, Noise, Dust, Fumes

Chemical CO (gas exposure), Chronic gas

General Fall of material, Pressed between objects, Hit by objects, Foreign particle in eyes, Slip & Fall, Muscular-Skeletal Disorder, Fall from height

Electrical Flash over, Electrical shock

5. PROBLEM SPECIFICATION

In this project , our aim is to design a lifting system which will be able to

lift objects to the rooftop of the foundry shop. The max load to be lifted is

almost 40 kg and taken the factor of safety as 2.The design of the lifting

system is to be made in a CAD software and then analyzed to see whether

the stresses are within the limits so as to make the arrangement safe i.e.,

to prove theoretically with the help of mathematical formulae and

concepts of design of machine elements that the lifting system has

minimum defects and has the required strength to lift the weight.

Moreover, the lifting system must be able to move the object towards the

worker for his/her safety.

6) LIFTING SYSTEMS PRINCIPLE

Lifting systems are required in almost every shop in Bhilai Steel Plant.

They are used to carry heavy loads from one place to another. From

simple pulley mechanisms to large overhead cranes, there is a need of

lifting systems in foundry and pattern shop to move ingot moulds as well

as other products from one place to another. On the rooftop of foundry

shop, a walkway is built on which the worker can stay till the completion

of task. This walkway provides safety to the worker while working on

rooftop of this shop and reduces accidents. Hence, in the foundry shop, a

lifting system was required which can lift the loads easily but also at the

same time can providing object directly to the worker on the walkways.

Also ,many design considerations have to be kept in mind while

designing lifting system such as stresses on roof, truss members, position

of winch, etc.

Many different types of heavy lifting equipment are available in the

marketplace, including forklifts, winches, hoists, cranes, and vacuum

lifts. Each machine uses a unique mechanism to manipulate a large and

heavy object; some devices move the item up and down or side to side, as

well as a combination of both movements. Normally, a business will

purchase or lease heavy lifting equipment based on the specific industry's

needs.

7) MECHANISM USED

In our project, a lifting mechanism was required which can lift the load

and automatically transfer the load to the worker. Hence, a rotating lifting

mechanism was designed. The main components of this system are:

1. Plates

2. Channels

3. Pipes

4. Pulleys

5. Bearing housing

6. Cantilever channel

7. Angles

8. Wire ropes

9. Winch

A vertical plate is welded to the truss members so as to provide

support on both ends. On it, angles are welded. 3 channels, each of

[-section and of equal dimensions are used and are permanently

fixed to the vertical plate by means of welds or through rivets.

Angles provide support to these channels since they are very long.

On these channels, a horizontal plate is permanently fixed which

acts as a base or foundation to the pipes. 2 pipes are used, both are

hollow through which rope goes downwards and is connected to the

winch. One pipe is movable while the other is fixed to the plate.

Bearings are mounted between the 2 pipes which offer rotational

movement to outer arm. A cantilever channel of [-section is attachd

to the outer pipe and both of these work as a single unit. Pulleys are

mounted on the cantilever channel on both ends through which rope

is passed. Finally ,through pulleys, rope is connected to a winch

which provides necessary power for lifting loads. This also provides

safety from power cuts during lifting and avoids accidents. A

schematic diagram of this complete assembly is shown below:

Hence, the above mentioned design was proposed.

8) VALIDATING THE DESIGN

The material selected is mild steel 30C8 (Syt = 400 N/mm2)

a) Checking stresses on base plate

i. Compressive stress

Taking into account factor of safety

Load acting on plate (P) = 80 kg

P = 80*9.81 = 784.8 ~ 800N

Area of cross section (A) = l*b

(500 * 666)mm2 – (π*1002/4)mm2

A = 325146.02 mm2

Since hollow pipes are also mounted on the base plate which also induces

compressive stresses on plate.

Load due to each hollow cylinder =780.22 N

Net load acting on plate = 800 + (2*780.22)

P = 2360.44 N

Therefore, compressive stress = P/A

2360.44/325146.02 = 0.0073N/mm2

The design is safe.

ii) Bending stress

Bending moment acting on plate (Mb) = P*e

Mb = 800 * 250 N-mm = 200000 N-mm

Distance from neutral axis = 12/2 = 6mm

Moment of inertia of plate about horizontal axis passing through its

C.O.G = 666*123/12 mm4 = 95904 mm4

Bending stress = Mby/I N/mm2

=1000000*6/95904

=12.512 N/mm2

The bending stress is within the limits. Hence, the design is safe.

b) Stress on vertical plate

i) Crushing failure

load (P) = 800 N

compressive stress = P/(b*t) N/mm2

= 800/(666 *8)N/mm

0,.15 N/mm2

c) Checking failure on pulleys

i) Crushing stress on pulley by pin

Shear stress = P/{b(d0-d)/2)} N/mm2

b= width of pulley = 30 mm

d0 = outer diameter of pulley = 100 mm

d = Inner diameter of pulley = 20 mm

Therefore, τ = 800/{20 *(100-20/2)} N/mm2

τ= 1 N/mm2

But permissible shear stress (τmax) = 0.5 * Syt/fos

τmax = 0.5 *400 = 200 N/mm2

Hence, the design is safe.

ii) Shear stress on pin by pulley

Area under shear = 2*(π*d2/4) N/mm2

τ = 800/(π*202/4) N/mm2

τ = 1.278 N/mm2

Hence, design is safe.

iii) Crushing stress on pin by pulley

By formula,

Crushing stress = force/projected area

=800/(20 *32.44) N/mm2

Crushing stress = 1.233N/mm2

The design is safe.

d) Channel

i)Crushing failure

Since there are 3 channels

Total load acting on channel (P)= 780.22+307.73 N = 1087.95 N

For 1 channel

Projected area = 500*60

Crushing stress = 1087.95/(500*60*3) N/mm2 = 0.0121 N/mm2

ii) Bending stress on channel

load (P) = 800 N

distance (s) = (6000-250) mm

Bending moment(Mb) = P*s

Mb = 800*5750 N-mm

Moment of inertia (I) = 10102683.33 mm4

Distance from neutral axis (y) = 125/2 mm = 62.5 mm

Bending stress = (Mb*y/I) N/mm2

=28.46 N/mm2

The design is safe.

e) INNER PIPE

i) Checking for shear stress

Projected area = π(d12-d2

2)/4 mm2

Shear stress (τ) = P/A

τ = 0.283 N/mm2

ii) Checking for torsional stresses

Moment of horizontal force P about pipe = 800*1000 = 800000 N-mm

Polar moment of inertia of pipe (J) = π*{(d1)4-(d2)4}/32

J = 2899285.71 mm4

By formula, torsional shear stress = Mt*r/J N/mm2

Torsional stress = 800000*57.5/2899285.71 N/mm2

=15.87 N/mm2

Since the stresses are within limits, hence our design is safe

f) Outer pipe

Inner diameter (D) = 100 mm

Outer diameter (D0)= 115 mm

Area under shear (A) = π*(1152 -1002)/4 mm2

Shear force acting on outer pipe = 800 N

Shear stress (τ) = 800/{π(1152-1002)} N/mm2

τ = 0.3157 N/mm2

Since the stresses are within limits, the design is safe.

g) Design of cantilever arm

i) Bending stress

The moment of inertia of the [-section is calculated and is found to be

10102683.33 mm4

Distance of load P from the point of contact between cantilever arm and

hollow pipe (e) = (1250-57.5) = 1192.5 mm

Load (P) = 800 N

Bending moment acting on arm (Mb) = P*e

800*1192.5 N-mm = 954000 N-mm

Distance from neutral axis (y) = 125/2 = 62.5 mm

Bending stress on arm = Mb*y/I N/mm2

954000*62.5/10102683.33

5.902 N/mm2

The design is safe.

HENCE , A CONCLUSION CAN BE DRAWN FROM THE ABOVE ANALYSIS

S.NO PARTS DIMENSIONS (mm) VALIDATION

RESULT1 VERTICAL

PLATE

750*750*8 DESIGN IS SAFE

2 BASE PLATE 666*500*12 DESIGN IS SAFE

3 CHANNEL 6000*125*60 DESIGN IS SAFE

4 INNER PIPE D0 = 100, Di = 80 DESIGN IS SAFE

5 OUTER PIPE Do = 115, Di = 100 DESIGN IS SAFE

6 PULLEY 1 D0= 100, Di = 20, b =32.44 DESIGN IS SAFE

7 PULLEY 2 D0= 100, Di = 20, b =32.44 DESIGN IS SAFE

8 CANTILEVER

ARM

1250*125*60 DESIGN IS SAFE

9 BEARING

HOUSING 1

AS PER AVAILABLE IN

SHOP

DESIGN IS SAFE

10 BEARING

HOUSING 2

AS PER AVAILABLE IN

SHOP

DESIGN IS SAFE

PROPOSED MODIFICATIONS

In order to improve the working condition and efficiency of the lifting

system, a stiffener can be provided on the cantilever arm so as to provide

strength as well as to reduce the risk of failure due to bending. Since the

cantilever arm is very long, it produces a large moment which consequently

produces high bending stresses in the section. To avoid this, a stiffener can

be provided which will act as a support to the arm. Thus, with this

modification, the shear stresses acting on the contact region between the

arm and the hollow section will also be reduced as well. The stiffener can

be welded to the lower portion of the cantilever arm so that it will not cause

any kind of discomfort to the worker.

REFERENCES

Design of Machine Elements - V.B.Bhandari Manufacturing Technology – R.K. Rajput Work Study - ILO www.wikipedia.org www.sail.co.in http://www.custompartnet.com/quick-tool/weight-calculator

Final Report BSp

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