hi i am putting some interview questions
GE
1.Is stress depends on material property?
ans : stress is defined as resistance force offered by the material per unit area.
3.there is a cantilever beam if i heat the beam to certain temp, how much stress is developed in that body.
Ans: there is no stress developed in the body, because we are allowing the beam freely to expand , stress is defined as resistance offered by the body per unit area, here there is no resistance force offered so there is no stress.
4. how many natural frequencies and mode shapes can beam has? why?
Ans:n number of mode shapes and n number natural frequencies, reason: the continuous system can be represented by n number of spring mass systems.
5.what is the difference between linear and non linear vibrations?
Ans: if initial conditions of any system is very high then we treat it as nonlinear vibrations. for ex: take simple pendulum if we give more excitation to the pendulum u will observe the oscillations and rotaions over. take example of turbelence of fluids with high velocity initially, hurricanes....etc
6.what are the modes of fracture mechanics?
Ans: 1.mode1: force applying normal to the plane
mode2: shear force
mode3: out of plane shear.
7.Difference between fatigue and dynamics load
Ans : fatigue and dynamics loads are different
fatigue: repeated cyclic loading like reversal bending,twisting---etc
dynamic loads: force varies with time.i.e transient loads like wind loads---etc
8.what is the S-N curve
Ans :stress versus no of cycles
9. what is there on y axis of the S-N curve
Ans : reversal stress,S-N curve constructed based on reversal stress applied over number of cycles.
10. if we have an extra line in S-N curve what it represents??
Ans: 1.For another material for application of reversal stress
2. for different r ratios of same material r=sigma min/sigma max
11.what is rain flow counting??
Ans: refer any site
