Can you show me the calculation? Is there anybody else who has solved it but has the same issue with the solution?

Where do you think self-weight stress should act?

The uniform load case is what we discussed in the class as well as in the book — look at Figure 10.2 for example; none of the stresses were concentrated.

As the mean stress in increasing from Zero to 10 then the number of cycles the component can sustain should decrease but

by calculation the calculation, the cycles are coming out to be greater than for zero mean stress… and also for negatine mean stress the cycles are coming out to be lesser than for zero mean stress… plz. check

How to consider self weight stress and at which point? How to take uniform load into consideration as in book fracture toughness relation only

for concentrated force has been given??

sir, this means that the shape of the balloon dos not matter, it can be circular, elliptical or rectangular or anything else…

If you want, you can make the balloon rectangular!

sir, that is there but the expansion of balloons cannot be completely determined by just two quantities? how to determine their area, is it done by approximation?

Dear Karan,

The ranges are so that you would plot baloons — as you might have noticed from so many property plots that we used in the class as well as from your textbook!

Sir, in the problem sheet 13, some of the values have been mentioned in ranges. how do we define the variation in between the ranges and hence plot them?

In case of weight gain, the oxide film is adhered to the surface of material.Depending upon the quality of adherence the weight gain is linear or parabolic.

But in case of weight loss, oxide film get detached from the surface and new surace is exposed for oxidation.Thus the oxidation takes place at constant rate to give linear weight loss.

Sir, in the ch-17 of ashby book on pg-389 weight loss rate is shown only as a linear function of time, but the weight gain is shown as both linear and parabolic function… why is it so?

sir,

if the presentation is based on the same paper and all the figures that have been used in the paper are to be used till then we have to use the image courtsey for each figure???

Dear Anirudh,

Yes; every figure, graph and data should be attributed unless they are from you or your own research. This is not just for our presentation; in any presentation, if there are no attributions, the audience will assume that they are your own. So, it is better in all presentations you make, to note the attributions properly.

Guru

Sir,

if i am giving presentation on a single research paper then what i am supposed to write (image courtsey) under the figure taken from the same paper?

sir,

we want to minimize the power loss but by using hybrid cables with core of copper, we are increasing the resistivity twice as coppper cable cable only..which inturn increases the power loss.. Is it minimises the power loss along providing the strength ?

Dear Aniruddh,

I looked through the formula; I think the expression for the saturation magnetisation given in the book is not correct; I believe there should be no mu0 in the expression.

Guru

Sir,

The unit of Ms is coming out to be Wb/m^2 after solving problem but as per the book, it should come out to be A/m.. plz check that

Dear Karan,

Why is that? You are given diffusivity; you know how much of distance should the heat be conducted; given these two data, isn't it straightforward to find the time needed?

Guru

Sir, so then how to continue with the problem, still it is difficult to move further…

Dear Karan,

I agree; it should be metre^{2} per second; I guess the book mistakenly gives the units of alpha, expansion coefficient for a, the thermal diffusivity.

Guru