20
votes
Is it structurally sound to cut an I beam to a T on one end?
While not an ideal situation, it is common enough that this type of cut/reduction of the beam as it comes to its support actually has a name. This is more often referred to as a coped or dapped steel ...
- 1,241
20
votes
Aluminum weight saving
I believe it has less to do with strength and more to do with stiffness. A rod of aluminum of the same length and weight as a a steel rod will be just as strong (force required to break) but have ...
- 5,629
17
votes
Is it structurally sound to cut an I beam to a T on one end?
This is a textbook example of what not to do.
We don't get into stress concentration at the cut off of the corner of the beam, or the fact that the two very different stiffnesses of the beams are a ...
- 22.8k
11
votes
Accepted
What happens from B to C in this stress strain diagram of mild steel?
One point of note is that the yield region is not as cleanly defined as BCD is in the image (although most books have it that way).
In reality the yield region looks like
The following image is one ...
- 24.3k
10
votes
Accepted
How does the strength of a square tube depend on the side size?
Flexural capacity is based on the stress at the extreme fiber (the point farthest vertically from the neutral axis).
$$\sigma = \frac{My}{I}$$
Or, rearranging
$$M = \sigma \frac{I}{y} = \sigma S$$
...
- 2,760
9
votes
Aluminum weight saving
TL;DR: Materials perform differently under different loading conditions. Some applications are more suited for steel others for aluminium
I will try to give another more general perspective/approach, ...
- 24.3k
8
votes
Accepted
How to strengthen an I beam
If your beam design is governed by yielding in bending (not lateral-torsional buckling/plate buckling, etc) then you need to increase the second moment of area (I) to increase the bending capacity.
...
- 2,651
8
votes
Can I weaken a coil spring consisting of spring steel?
You could try a bath of concentrated acid. As long as you could maintain circulation so the concentration was fairly constant, a spring presents a very uniform cross-section and should be dissolved at ...
- 91
8
votes
Is it structurally sound to cut an I beam to a T on one end?
If the white beam on the left is adequate, the one on the right is much bigger than it needs to be, so hacking a piece out of it might not matter.
In general this idea is a horrible example of ...
- 12.6k
7
votes
Is it structurally sound to cut an I beam to a T on one end?
TL;DR: Since we can't see how the beam is supported on the other end, its not clear whether its structurally safe. Still, I don't believe this configuration can transfer safely any substantial ...
- 24.3k
7
votes
Is there a maximum life for things made out of stainless steel or cast iron?
Strictly speaking, very few metals are "stable" in terms of the laws of thermodynamics. True chemical stability is when the atoms are in their lowest energy state. For most metallic elements,...
- 191
6
votes
What thickness of aluminium sheet do I need to achieve the same strength of a 1/8" steel sheet?
Using your plate as boat hull implies a complex load profile probably involving compression, shear and bending, possibly even torsion.
In such cases, it is effectively impossible to give a simple ...
- 13.1k
6
votes
Aluminum weight saving
Sometimes the strength isn't required, so size for size, aluminium is lighter.
e.g. bicycles often use aluminium screws to hold the bottle cage to the frame. The size of the screw is set to be ...
- 7,771
5
votes
Accepted
Steel Structure connection pin or fixed
Pinned connection in structural context doesn't mean free rotation/zero moment. Pinned connection means much bigger rotations and much lower strength compared to the connected members. According to ...
- 347
5
votes
Accepted
Why are steel I-beams mostly symmetrical?
Academically, I believe you are correct in that you could potentially optimize an I-beam to have a higher failure-load to mass ratio. You would have to play with the area moment of inertia equations ...
- 8,285
5
votes
Accepted
Spring degradation in hand grip trainer
for a properly-designed (right materials, right size, right manufacture) spring of that type, the applied stresses are far too small to cause any plastic deformation (permanent bending) at all. ...
- 15.3k
5
votes
Which post would be stronger?
The incorrect posts are weaker as it is the dimension perpendicular to the fence which is critical. It sounds like you have a breach of contract here so you should ask them to replace with the ...
- 7,771
5
votes
What happens from B to C in this stress strain diagram of mild steel?
Point "C" is the "offset yield point" or "proof stress" as described below.
The yield strength or yield stress is a material property and is the stress corresponding to ...
- 8,232
5
votes
Accepted
Can electric furnaces be used for steel production from ore?
It's almost certainly true that an electric arc furnace isn't adequate for steel production, at least not by itself.
It depends on what phase of steel making you care about though. An electric arc ...
- 550
4
votes
Are British Universal Beams and Columns cut according to imperial or SI measurements?
There is a misnomer in the question in that the beams are not cut to section at all, and not measured with any sort of ruler during manufacture. The sections are rolled on a hot rolling mill where ...
- 632
4
votes
How can the alloying materials of recycled steels be separated?
First the scrap is separated at the source ; for example cast iron generally only contains Si and Mn. High vapor pressure elements boil off or collected in the flux/slag : eg, Zn, Pb, Sn, Bi, An ,,,,...
- 6,182
4
votes
Accepted
Steel : is Damascus steel still relevant compared to modern alloys?
Damascus and Samari blades are artisan made , so have variations. They were a very clever way to make medium carbon steel before the science was understood. They are a combination for wrought iron ( ...
- 6,182
4
votes
What's the difference between tempering and aging?
Although the time and temperatures may be the same, different things are happening. Tempering generally reduces hardness/strength, but improves toughness. Aging martensite is done for a group of ...
- 6,182
4
votes
Accepted
What are the design difference of a steel tank that would withstand 136atm inside and 1atm ambient compared to 1atm inside and 136atm ambient?
It's the difference between holding up a weight by by hanging it from a cable vs. putting it on top of a column.
A tank that starts out round (ideally, if it starts out spherical) and is pressurized ...
- 2,767
4
votes
Can I weaken a coil spring consisting of spring steel?
By "strength" do you mean stiffness/modulus? The modulus does not change with tensile or yield strengths. Make it with wire of 1/2 the diameter for 1/2 the modulus. Acid will hydrogen stress crack ...
- 6,182
4
votes
Accepted
Could a bolt this size actually be used on a project?
From my location it appears the image is broken, however I can assume with my imagination and the comments it’s a pretty big bolt.
Exceptionally large bolts are surprisingly not that uncommon. They ...
- 729
4
votes
Is it structurally sound to cut an I beam to a T on one end?
The lower flanges resists a downward bending force that puts tensile stress on the lower flanges. Removing a short section of the lower flange lowers its bending strength but because of the very short ...
- 6,182
4
votes
Is it possible to determine how the steel was made, having its microstructure (for example, to distinguish forging from rolled products)?
Steels are usually considered "as cast" or wrought. The microphotograph is overetched and either high magnification or coarse grained , likely had a heat-treatment. Cast or wrought would be ...
- 6,182
4
votes
Accepted
Exactly what makes steel-concrete composite beam better than pure steel?
Some other answer have touched upon this, but I think it needs to be made explicit:
Your mistake is in thinking that civil engineering is about making the lightest structure possible. It's not. ...
- 13.1k
4
votes
Aluminum weight saving
When Zeppelins were designed, only non-sparking materials were allowed for them so the hydrogen gas that invariably seeps from the gas bags would not find an ignition source. Steel did not qualify.
...
- 163
Only top scored, non community-wiki answers of a minimum length are eligible