Calculate the critical crack length, Mechanical Engineering

Assignment Help:

Calculate the critical crack length:

A wide plate of mild steel is subjected to uniform tensile load causing a stress of 100 MPa. Calculate the critical crack length in the centre of plate which when reached will cause the plate to fracture, if fracture toughness of mild steel is 1340 N / mm2

Solution

The crack will become unstable in the centre of the plate, i.e. the fracture will occur when the crack has attained a critical length (say ac) under given stress ? which remains constant. At this moment KI → KIC.

KI for a large plate with central crack of length 2a is by Eq.

1433_Calculate the critical crack length.png

and hence

211_Calculate the critical crack length1.png

or        

629_Calculate the critical crack length2.png

∴          2ac = 114.3 mm

[This example explains how the knowledge of fracture toughness of material and KI of a crack can be used to calculate the length of a crack which must not be permitted to exist. If the cause of crack extension may not be controlled, the only thing left to designer is to calculate critical length in advance. Then the crack length would have to be monitored throughout the life of the structure and as soon as it approaches the critical value, the structure should be discarded to avoid sudden fracture or other measures be taken by which either KI is reduced to KIC is improved.]


Related Discussions:- Calculate the critical crack length

Example of shear force and bending moment diagram, Example of Shear force a...

Example of Shear force and bending moment diagram: Q: Draw the Shear Force and bending moment diagram for the simply supported beam loaded as shown in the figure given belo

What are the role of roads in design of a plant, Q. What are the role of Ro...

Q. What are the role of Roads in design of a plant? Roads are an important part of the design of a plant, as they provide access and separation during normal operation as well

Desing, what is the maximum principle stress

what is the maximum principle stress

QFD chart and engineering specifications, Deliverables: A QFD chart, sh...

Deliverables: A QFD chart, showing the relationships between the customer requirements and the engineering specifications. (Refer to the Ullman QFD chart posted on My

I-Section, An unsymmetrical I-Section as shown in figure below. If maximum ...

An unsymmetrical I-Section as shown in figure below. If maximum bending stress is not extend more than 40MPa in the section than find out the moment which it can bear

Steam, what is dry ness fraction?

what is dry ness fraction?

Cost of processing the payroll, The processing of payroll for the 10,000 wo...

The processing of payroll for the 10,000 workers in a large rm can either be done using 1 hour of computer time (signed by K) and no clerks or with 10 hours of clerical time (sign

Special tool and cleaning of part general service tips , Special Tool: Use...

Special Tool: Use special tools wherever applicable. Special tools are designed to dismantle or assemble a specific part or assemblies without causing damage to them. Cleaning

Section modulus, Section modulus: Define the Section modulus. What d...

Section modulus: Define the Section modulus. What do you mean by torsional section modulus or polar modulus?  The moment of inertia of plane about the axis perpendicula

Describe about carbon steel, Q. Describe about Carbon Steel? Steel havi...

Q. Describe about Carbon Steel? Steel having no specified minimum quantity for any alloying element (other than commonly accepted amounts of manganese, silicon, and copper) and

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