Recent content by ehabmozart

My question here is regarding fracture of materials. I have problems in understanding some concepts. Now, for static loading, there is a property called KIC (fracture toughness). By equating our stress from the static load to this KIC, we get the maximum length of the crack which does not...

Oh yes, that's true and I totally understand each screenshot. It just a convention. Back to our discussion, can you explain to me the second last attachment and the existence of the 3D triangle and the effect of ACME thread having an angle alpha on the drawing. Moreover, how does this relate to...

Now for the previous post (where I attach the image) Check how alpha influences the calculations. Intact, I'll show you another screenshot of where F acts exactly according to my book. Can you see the attached picture. Where does F act? I can;t still visualize it. Fill me up with your...

I forgot to attach the screenshot :S

Allright.. I think that was a valuable point. Now my question regarding the 3D image of the triangle. I attached a screenshot from a youtube vid which shows the 3D triangle of an ACME thread. Now, this is just mind blowing. How did he get the alpha and more precisely if it was a square what...

I'll explain what exactly do I mean. Now there is an a force from up (let us say the weight of the car). This exerts the F which points downward as shown in the picture. Fine. Now, we are after the torque required to raise the car up. Yes? Fine. So what have the done is calculating the P...

. Well, i thought stress is the force/area. I still don't get your point here. Now the F/2 doubt is solved. Thanks. My question here is let's say there is car at the top which exerts F. How when we draw the right triangle, we speak about the torque to raise F. The triangle represents one turn of...

Sir, I OWE YOU BIG TIME.. Your reply was just like a Christmas gift. Thanks a lot. Check this link. I was about to post it. It has the visualization as well but yours is way better now. Check it out "http://www.cadcamengineering.net/pitch-diameter-lead-or-helix-angle-and-percent-of-threads/". I...

Thanks a lot to both of the replies. Mmmm.. Well, for the first reply. Can you be more precise here?? I mean how can I think 'perpendicular'... For the second reply.. If i wrap a right triangle around the pencil. Fine. Now I unwrap it and the surface of the paper is the ramp. Where did the...

Hello So at the moment, I am reading through Shigley's Mechanical Engineering Design book. I've come, at, last, to the first application chapter. Screws, Fastners.. etc. Since I lack experience, what I am trying right now is to visualize every single diagram in this chapter and...

Thanks a lot stockzahn once more for replying. I just appreciate this long and elaborate reply, which shows your professionalism in helping. This is a virtue. Back to your reply. Well, I gave it a bit of thought and would like to share it with you. Some agree with your points and the other...

First of all, stockzahn, I thank you for your effort and time to look at my question and reply. I highly appreciate it. Moving to your reply, I get the first part until the sentence "now there is a problem...". I definitely understand that strain and area deformation are interchangeable due to...

Hey there! While reading my mechanical design book, I had hard time to understand a particular paragraph if anyone could help. Attached to this post are two figures. 2-6 a and b. The first one is pretty simple to understand; the engineering normal stress strain curve...

Why does or how does combustion of fuel and air in a combustion chamber in a brayton cycle is idealized by a CONSTANT pressure. I remember that in a diesel cycle, it was idealized by constant pressure because as P increases by ignition but the volume increase offsets this increase. However, in...

Your approach just misses the friction component which acts against the relative motion of box/wall (i.e. downwards).. Therefore the equation will be F(push)sin45 - mu*N - mg = 0 ; where mu is coefficient of friction and N= F(push) cos 45 ...