Determine the number of cycles - crack propagation, Mechanical Engineering

Determine the number of cycles - crack propagation:

The plate of above Example  contained a crack of 50 mm length in the centre before it was subjected to cyclic stress. Determine the number of cycles the plate would undergo when final fracture occurs.smax = 100 MPa, smin = 30 MPa and law of crack propagation for material of plate is

         da  / dN  = 10-8 (Δ K I )2.25 mm/cycle


The half crack length at which fracture will occur was calculated as ac = 57.17 mm.

924_Determine the number of cycles.png

553_Determine the number of cycles1.png

∴          Δ K I =  K I max  - K I min

1315_Determine the number of cycles2.png

Using this value of Δ KI in law of fatigue crack propagation, i.e. the plate is likely to fracture under smax = 100 MPa,smin = 30 MPa if plate contains a central crack of 50 mm length, after 1048 cycles.

1764_Determine the number of cycles3.png

da / dN  = 10-8 (124)2.25 (a)2.25 / 2

= 0.51´10- 3 (a)1.125

Posted Date: 1/22/2013 2:06:43 AM | Location : United States

Related Discussions:- Determine the number of cycles - crack propagation, Assignment Help, Ask Question on Determine the number of cycles - crack propagation, Get Answer, Expert's Help, Determine the number of cycles - crack propagation Discussions

Write discussion on Determine the number of cycles - crack propagation
Your posts are moderated
Related Questions
SHAF T IN PARALLEL: SHAF T IN PARALLEL: The shaft are in parallel when the driving torque is applied at the junction of shafts and resisting torque is at other ends of

assumptions made in deriving a bending formula

Feeler Gauge: It is used to measure minor clearances. Feeler gauges come in set of a few blades of different thickness as shown in Figure. It is used to measure the spark plug gap

Q. Plant layout and equipment spacing? Layout refers to the location of plants (and process/power units within the plants and associated utilities (or balance of plant)) as wel

Branches of mechanics: Mechanics is basically divided in to two parts Static's and Dynamics, Dynamics is further divided in kinematics and kinetics Statics: It deals with

Q Describe about Push-pull welds? - A push-pull system employs transformers with an electrically reversed polarity arrangement wherein two transformers complement each o

Q. Briefly explain Model scale design? Knowledge of dynamic similarity conditions enables evaluation of model scales. Almost alI the problems related to river hydraulics are ab

Longitudinal strain produced - hollow cast iron cylinder: A hollow cast iron cylinder 4 m long, 300 mm is the outer diameter, and thickness of metal 50 mm is subjected to cen

Q. What is Slush moulding? Slush moulding is an excellent method for producing open-end objects. It is an inverse process of dipping, in which the inside of the mould is coated

Centrifugal Filter and Screen Filter Cleaning :   Oil may contain impurities. Since the oil passes through all the engine parts, the impurities may harm the parts and cause imprope