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Sunday, 9 August 2020

PROBLEM 1.1

          A rod 300 cm long and of diameter 4.0 cm is subjected to an axial pull of 20 KN. If the modulus of Elasticity of the material of the rod is 4.0 x 105 N/mm2; Determine:
(i) The Stress, 
(ii) The Strain, and 
(iii) The Elongation of the rod.

Sol:
Given,  Length of the rod, L = 300 cm,
              Diameter,               D = 4.0 cm = 40 mm, 
              Area,                       A = (Ï€/4) D2 = (Ï€/4) 40 = 400 Ï€ mm2
              Axial pull,              P = 20 KN = 20,000 N
             Modulus of Elasticity, E  = 4.0 x 105 N/mm2

(i) The Stress (σ) is given by equation as
                         Ïƒ = P/A = 20,000/400 Ï€  = 15.92 N/mm2 
                 
(ii) Using the equation, the strain is obtained as 
                         E = σ/e
Strain              e = σ/E = 15.92 / 4.0 x 105 = 0.0000398

(iii) Elongation is obtained by using equation as
                          e = dL/L
Elongation,     dL = e x L  = 0.0000398 x 300 = 0.01194 cm
                   
              
Credits: Books.google.co.in
                Scribd.com

RELATION BETWEEN STRESS AND STRAIN

FOR ONE-DIMENSIONAL STRESS SYSTEM:
          The relationship between stress and strain for one directional stress (i.e., Normal stress in one direction only) is given by Hook's Law. This law states that when a material is loaded within elastic limit, the developed normal stress is proportional to the strain produced. This means that the ratio of the normal stress to the corresponding strain is a constant within the elastic limit. This constant is represented by E and is known as Modulus of Elasticity or Young’s modulus of Elasticity.

FOR TWO-DIMENSIONAL STRESS SYSTEM:
          Before going to learn about Two dimensional stress system, we have to know about Longitudinal strain, Lateral strain and Poison's ratio. 
1. Longitudinal Strain:
          When a body is subjected to an axial tensile load, then there is an increase in length of the body. But at the same time there is a decrease in other dimensions of the body at right angles to the line of action of the load applied. Thus the body having axial deformation and also deformation at right angles to the line of action of the applied load (i.e., Lateral deformation).
          The ratio of axial deformation to the original length of the body is known as Longitudinal strain (Linear). The Longitudinal strain is also defined as the deformation of the body per unit length in the direction of applied load.    
2. Lateral Strain:
          The strain which is produced right angles to the direction of applied load is known as Lateral strain.   

          Let us take an example, A rectangular bar of length 'L', breadth 'B' and depth 'D' is subjected to an axial tensile load 'P' as shown in below fig., . The length of the bar will increase while applying load, the breadth and the depth will decrease.

Let     Î´l = Increase in length
          δb = Decrease in breadth and, 
          δd = Decrease in depth.

Then Longitudinal strain = 
and Lateral strain =

Note: 
1. If longitudinal stain is tensile, the lateral strain will be compressive, vice-versa,
2. Hence for every longitudinal strain in the direction of the load applied is accompanied by lateral strain of the opposite kind in all directions perpendicular to the load.

3. Poisson's Ratio:
          When the material is subjected to stress within the elastic limit, The ratio of lateral strain to longitudinal strain is a constant. This ratio is called Poisson's ratio and it is denoted by a symbol 'μ(MU).

Mathematically, 

as lateral strain is opposite in sign to longitudinal strain, hence algebraically, lateral strain is written as,  

4. Relation between Stress and Strain:
          Consider a two dimensional figure ABCD, subjected to two mutually perpendicular stresses 


Credits: books.google.co.in
                scribd.com

URBAN LOCAL BODIES

Overview of Urban Local Bodies:

          Municipal governance in India has existed since 1687 with the formation of Madras Municipal Corporation, and then Calcutta and Bombay Municipal Corporation in 1726. In 1882 the viceroy of India Lord Ripon (Who is known as the Father of Local Self Government) passed a resolution of local self-government which laid the democratic forms of municipal governance in India.

          Urban Local Bodies (ULB's) in Andhra Pradesh are traditionally mandated to undertake certain basic functions like Water supply, Sewerage & Septage, Roads, Drains, Street Lighting, Parks and Burial Grounds. The Twelfth Schedule of Constitution (Article 243 W) provides an illustrative list of Eighteen functions, that may be entrusted to the municipalities.
          After the advent of constitution 74th Amendment Act (CAA), 1992, the functional domain of urban local bodies has been expanded to include development programs along with traditional civic functions.  Due to Globalization, Liberalization and more critically, the urban explosion has increased the volume of services to be delivered by the urban local bodies.

CATEGORIES OF ULB’S :
          In Andhra pradesh ULS’s are divided into Six grades based on Annual Income and Population.
Grade
Annual Income
Selection Grade
Rs. 8 crores and above
Special Grade
Rs. 6 crores to Rs. 8 crores
First Grade
Rs. 4 crores to Rs. 6 crores
Second Grade
Rs. 2 crores to Rs. 4 crores
Third Grade
Rs. 1 crore to Rs. 2 crores
Nagar Panchayats
Below Rs. 1 crore

Functions of Urban Local Bodies:
          As per the provisions of the Municipality Acts & Corporation Acts, the Urban Local Bodies are entrusted broadly with the following functions.

1) Public health, sanitation, conservancy and solid waste management.
2) Provision of water supply, drainage and sewerage.
3) Construction and maintenance of roads, drains, culverts and bridges.
4) Provision of street lighting.
5) Urban poverty alleviation programs.
6) Slum improvement and up gradation.
7) Provision of public parks and play grounds.
8) Construction and maintenance of public markets, slaughter houses.
9) Urban planning including town planning.
10) Regulation of land use and construction of buildings.
11) Maintenance of secondary and elementary schools.
12) Urban development programs.
13) Vital Statistics including Registration of Births and Deaths.
14) Maintenance of burial grounds.

Sections in Urban Local Bodies:

S.NO
Section
Broad functions
1.
Administration
To look after general administration, including school administration and council meetings.
2.
Revenue
To assess and collect various taxes and non-taxes and collection of rents from municipal properties.
3.
Accounts
To maintain accounts, prepare annual accounts, budget, and attend to audit of accounts.
4.
Public Health and Sanitation
To look after sanitation, public health and solid waste management including medical and maternity services.
5.
Engineering
To look after water supply and sewerage, public works like roads, drains, buildings, parks and play grounds, street lighting
6.
Town Planning
To regulate town planning activities including land uses, layouts, building constructions and encroachments.
7. 
Urban Poverty Alleviation (UPA)
To look after urban poverty alleviation programs.


Credits: https://en.wikipedia.org/wiki/Municipal_governance_in_India
                cdma.ap.gov.in

Ward Energy Secretary -- Roles & Responsibilities

Role:-
 To assist the AEE / AE (Civil / Electrical) in Power supply and Street Lighting.
 He is store in-charge for O&M related materials for Street Lighting and Power Bore wells

 Responsibilities:-
} Maintenance of street lighting and power bore well motors.
} Electro-mechanical works of water supply in the ward
} Erection of new electrical poles
} Maintain diary for daily work done
} Any other duties entrusted by the higher authorities from time to time 



Ward Amenities Secretary -- Roles & Responsibilities

Role:-
To assist the AEE / AE in all engineering works.

Responsibilities:-
Delivery services to the door step of the public.
Investigate and prepare estimates for all engineering works and maintenance works.
Responsible to AEE / AE for all tasks.
Supervise all engineering works and maintenance.
Execution of Water Supply Distribution lines.
Construction of individual toilets to households.
Monitor daily water supply & arrest leakages.
Responsible to provide HSC's (House Hold Connections) to all the households.
Respond to the citizen charter, Puraseva and all Grievance and with in SLA (Service Level Agreement).
Maintenance of WTP & SS Tanks.
Preparation of estimate as per Standard specifications of APDSS.
Maintenance of quantity and quality of all engineering works, as per the standards.

Preparation and Maintenance
 of records,
 M. Books,
 safe custody of measurement books,  preparation of estimates,
 work bills,
 work slips, deviation statement including price adjustment.

Attend to all complaints / Grievances received in Spandana (or) from any platform.
Redressal of RTI Act.
Should follow the protocol.

Checking and Supervision all Engineering Works

 curing on CC roads, Drains, buildings and bridges works,
 checking of measuring boxes,
 screening of materials, cement mix, sizes of materials,
 quality of materials, quality of work (plumb, levels, corners etc.),
 clearance of site.

 Checking quality of water duly conducting

 the Residual Chlorine tests and
 microbiological e-coli tests with H2S vials etc.,


Desilting of major drains before onset of monsoons.
Maintenance of parks and traffic islands.
Maintenance of burial grounds and community toilets.
He is responsible for maintenance of culverts and bridges.
Maintenance of bore wells and power bore wells.
Survey of works & Submision of reports.
Any other duties entrusted by the higher authorities from time to time



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