All Questions
11
questions
0
votes
0
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20
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Determine moment and shear stress door
Determine shear stress and moment of bolt:
Internal Height of Door = 198.2 cm
Internal Width of Door = 89.9 cm
Thickness Door = 3.9 cm
Weight Door = 45.76 kg or448.9 N
Elasticity = 9.8 GPa or N/mm2
...
- 1
0
votes
2
answers
84
views
Failing engine A-Mount (bad design by the automotive manufacturer?)
I currently own a Tata Nexon Petrol car (in India) where I have seen (on facebook, Telegram, WhatsApp owner groups and youtube) that the A-Mount on the engine has suffered multiple failures for some ...
- 101
0
votes
1
answer
48
views
Why the size of top and bottom rollers is different in three point bend test?
In a short beam shear testing of polymers, the configuration is such that the top (loading) roller is bigger than the bottom (support) rollers. Why is this the case, and what happens when the size of ...
- 1
2
votes
1
answer
50
views
How is the assumption that stress and strain are elastic everywhere is valid for STRESS-LIFE method for fatigue life calculation?
Stress life method is generally employed for high-cycle fatigue (HCF) applications. while HCF region is approximated by $\sigma=a(N)^b$ which gives a linear graph on log-log scale, for steels it ...
- 41
1
vote
1
answer
50
views
Stability of 3D-printed mask after sterilisation
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6797553/
https://www.hatchbox3d.com/collections/pla
We are 3D printing masks that need to be used by medical staff treating COVID19 patients.
The first ...
- 111
5
votes
2
answers
9k
views
Calculating shaft diameter
I'm designing a circular shaft that's going to carry a spread radial load of about 200kg and also transmit a 160Nm torque. I'm not very familiar with materials but what I'm guessing I'll be able to ...
- 193
4
votes
2
answers
706
views
How to determine tensile strength while the normalised tensile strength is known?
I try to design a shaft with yet unknown diameter, i know the distribution of forces and stresses (shear, torsion and normal) in/ along the shaft. I need just one more parameter nl. the tensile ...
user14407
2
votes
1
answer
99
views
"The monofilament wire has a tensile strength of 18 kg" What does this mean?
I am used to strength being measured in units of stress, such as pounds per square inch, or Pascals.
I am assuming what the author is trying to say is, "this filament will break when holding 18 kg," ...
- 131
0
votes
2
answers
213
views
mean fatigue strength
In context of machine design, what is mean fatigue strength? (as I am thinking I am mixing it up with midrange strength)
In my class we deal a lot with steels and this is a low strength steel, but I ...
10
votes
4
answers
28k
views
Why does the stress-strain curve decrease?
This is a stress-strain diagram
I have noticed that the curve decreases between points C & D and between E & F.
Why does that happen? I expected the curve to always increase since the ...
- 471
0
votes
1
answer
9k
views
Maximum compressive force for pipe vs solid cylinder
If I have a pipe with external radius R and internal radius r. Maximum compressive force will be given by the same formula Fmax=σS as for cylinder or different? where $S = πR^{2}-πr^{2}$, and σ is ...
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