Engineering Stack Exchange
Engineering Stack Exchange

Most Popular

more tags
1500 questions
4
votes
1 answer

How to compare two ANSYS mechanical APDL databases? (.db or .dbb files)

I am new to using ANSYS. I use the student version. Is there a way to find what is the difference between two .db or .dbb files? I have two files say a.db and b.db, which are supposed to be the same exact model for a simple beam structure with one…
Nasser
  • 141
  • 3
4
votes
3 answers

Why would a column expand before accepting load through a narrow thunk?

Here's a column top which holds a driveway overbridge. The column is a reinforced concrete cylinder with an inverse truncated cone on top - so it expands sideways at its top. The column top holds some narrow thunk and that thunk holds the driveway…
sharptooth
  • 2,099
  • 17
  • 27
4
votes
3 answers

Why does paper under pressure become brittle?

In this popular YouTube video, a man attempts to fold a piece of paper more than seven times using a hydraulic press. After the seventh fold was applied pressure from the press, the man shows the audience that the paper became brittle, and breaks…
user01101001
  • 41
  • 1
4
votes
3 answers

Deflection of thin plate with 1 free edge and deflection > thickness

I have an thin uniform rectangular steel plate supported on 3 sides and free on one, and supporting a uniform load. I'm trying to determine what thickness of plate I need to keep deflection below a given value, but the deflection may not be "small"…
Stilez
  • 571
  • 6
  • 18
4
votes
2 answers

Viscosity of select species at atmospheric pressure for very large temperatures?

I'm dealing with hot combustion products flowing through heat exchangers and I'd like to perform some calculations regarding the flow properties (velocity, temperature, pressure and density) as it passes trough the heat exchanger. I've a 1D model…
André Almeida
  • 83
  • 5
4
votes
2 answers

6082 Aluminium softened by brazing. How to harden?

I've started playing around with brazing pieces of extruded aluminium sections to join them together for strong joins as an alternative to bolting them. The pieces are made of 6082-T6 aluminium alloy. I've found that the heating needed to braze…
Jodes
  • 1,304
  • 1
  • 12
  • 34
4
votes
1 answer

Foundation Excavation: How much larger than the RCC footing?

I am trying to estimate the volume of excavation needed for the foundations of a structure from the drawings provided. The drawings clearly give the dimensions of the RC / cement footing but I suppose the actual excavation will need to be larger…
curious_cat
  • 432
  • 3
  • 10
4
votes
1 answer

Why are drill bits always slightly undersized?

I have found that drill bits are always slightly undersized. For example, 10mm bits tend to be more like 9.8mm diameter. And in aluminium, the hole ends up being about 9.9mm. The same seems to be the case for conical stepped drill bits I've found it…
Jodes
  • 1,304
  • 1
  • 12
  • 34
4
votes
1 answer

Computer psu to directly power usb port

I'm not an engineer, but I build custom audio equipment and systems as a hobby. My question to you is: from a computer power supply (PSU) which converts AC power into DC of various voltages (12 V-5 V) would it be possible to power a Bluetooth…
user6236
  • 41
  • 1
4
votes
2 answers

How does one calculate degrees of freedom in a reactor with parallel reactions?

Some time ago, I was going through some exercises and I came across a odd question, for which my atomic species degrees of freedom did not match my degrees of freedom using molecular species. I showed my lecturer and he couldn't see why this was the…
Ender Delat
  • 143
  • 1
  • 5
4
votes
1 answer

Heat pump driven by a Stirling engine that requires no external work

I was considering some theoretical limits on transferring heat from one system at to another to another. It is well known that if you have two systems at temperatures $T_1$ and $T_2$, respectively, with $T_2> T_1$ then you need to provide work to…
Count Iblis
  • 141
  • 4
4
votes
3 answers

Why are the processes called "Precipitation Hardening" and "Solid Solution Strenghtening"?

Does precipitation hardening really only make the material harder while Solid Solution strengthening makes it stronger altogether (thus increasing the area under the stress-strain-curve edit: excuse the mistake here: the area under the stress-strain…
zero
  • 201
  • 2
  • 5
4
votes
2 answers

Tensile strength to weight conversion

I read in a documentation to some adhezive: the tensile strength is 13 N/mm2. How many kilograms can the 10x10mm bonding hold? I tried to calculate it by the following: $$\begin{align} F &= m/g \\ \therefore m &= Fg \end{align}$$ the strength is in…
kobame
  • 245
  • 3
  • 6
4
votes
2 answers

Estimate the grain size after grain growth

An uncold-worked brass specimen of average grain size 0.009 mm is heated to 600 degrees Celsius for 1000s, what is the average grain size based on this graph? How to tackle this problem? I don't know if I am using the graph correctly. My approach…
strateeg32
  • 517
  • 2
  • 13
  • 21
4
votes
3 answers

Can Fast Fourier Transform be used to monitor for fault vibrations in a hard disk?

We want to monitor hard disks for present problems or pending failure. Can the Fast Fourier Transform (FFT) of a given hard disk in question, then, be compared with a reference FFT for a perfectly working one, and then conclude hard disk may be…
Doug Null
  • 275
  • 1
  • 6
1 2 3
…
99 100