week 6

Question 1

what are the 5 modes of loading?

Answer 1

compression
tension
shear
torsion
bending

Question 2

what are the meaning/action of the compression, tension, shear torsion and bending

Answer 2

compression: pressing, pushing
tension : pulling
shear : sliding
torsion : twisting
bending : tension and compression

Question 3

what is fatigue?

Answer 3

failure of material when under cycle load.

Question 4

what does fatigue depend on to then end up a material failure?

Answer 4

depends on time, how long the cycle lasts, and how many cycles the material has been under load.

Question 5

what are the 4 characteristics of fatigue and meanings

Answer 5

progressive : fatigue process takes place of time
localisation : fatigue starts in the local area (not the whole material)
cracking : cracks from in areas where can’t withstand applied stress
fracture : last stage when the material fails

Question 6

what are the 6 design features which contribute to fatigue failure

Answer 6

sharp corners
surface roughness
notches
pre-existing cracks
temperature
stress

Question 7

what kind of pattern does cycle loading have on a graph

Answer 7

a random and complex pattern

Question 8

what equation is used to find out fatigue life

Answer 8

Basquin equation

Question 9

progressive

Answer 9

fatgiue process takes place of time

Question 10

localisation

Answer 10

fatgue starts in local area (not the whole material)