Discover the maximum safe air pressure, Mechanical Engineering

Assignment Help:

Discover the maximum safe air pressure:

A cylindrical compressed air drum is equal to 2 m in diameter along plates 12.5 mm thick. The efficiencies of the longitudinal (ηl) and circumferential (ηc) joints are equal to 85% & 45% respectively. If in the plating the tensile stress is to be limited to 100 MN/m2, discover the maximum safe air pressure.

Solution

The efficiency of the joint effect the stresses induced. For a seamless shell (with no joints), efficiency is equal to 100%. While the efficiency of joint is less than 100%, the stresses are enhanced accordingly.

Therefore, if η is the efficiency of a joint in the longitudinal direction, affecting the hoop stress, then the stress shall be given as,

σ h  =    pd/ (4t ×ηI)

Here, the diameter d = 2 m = 2000 mm.

Thickness, t = 12.5 mm.

Limiting tensile stress = 100 MN/m2 = 100 N/mm2.

Letting the circumferential joint which influences the longitudinal stress,

Pd/ (4t × ηl) = 100

p × 2000 / (4 × 12.5 × 0.45) = 100

 p = 1.125 N/mm2

Likewise, considering the longitudinal joint which influences the hoop stresses,

pd / (2t × ηc) = 100

p × 2000 / (2 × 12.5 × 0.85) = 100

p = 1.063 N/mm2

Evidently, safe pressure is governed through hoop stress.

Therefore, maximum safe air pressure = 1.063 N/mm2.


Related Discussions:- Discover the maximum safe air pressure

Advantages of resistance welding, Advantages of resistance welding   ...

Advantages of resistance welding   1. Resistance welding is very fast compared to arc welding. 2. Almost any combination of metals can be resistance welded provided necessa

Evaluate the stress in the bolt, (a) A steel bolt 650 mm 2 cross-sectional...

(a) A steel bolt 650 mm 2 cross-sectional area passes centrally through a copper tube to 1200mm 2 cross-sectional area. The tube is 500mm long and closed by rigid washers, which

What do you mean by centrifugal casting, What do you mean by centrifugal ca...

What do you mean by centrifugal casting ? How are the centrifugal method classified ?

What do you mean by synchromesh device, What do you mean by synchromesh dev...

What do you mean by synchromesh device ? explain the basic working of a synchromesh gear box.

Evaluate the work done by the gas during the expansion, (a) What do you und...

(a) What do you understand by the following : (i) Open System (ii) Closed System (iii) Concept of ‘Work' (b) 0.014 m 3 gas at a pressure of 2070 KPa expends to a pressure of

Kinetics, Kinetics: Define Kinetics. What is plane motion? Sol: ...

Kinetics: Define Kinetics. What is plane motion? Sol: Kinetics is that branch of mechanics, which deals with force system that produces acceleration and resulting motio

Governor, spring combined gravity governor

spring combined gravity governor

Determine the topological information of b-rep, Topological information of ...

Topological information of b-rep It provide the relationships among vertices, edges and faces similar to that used in a wire-frame model. In addition to connectivity, topologi

Fracture mechanics, difference between stress intensity factor and stress c...

difference between stress intensity factor and stress concentration factor

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd