All Questions
12
questions
0
votes
1
answer
158
views
How much force is acting on the screws I used?
Years ago I built a vertical rack to store long lengths of wood. The rack was built using 2x4" pine scrap. Imagine a typical wall assembly with a single top and bottom "plate" (2x4) ...
- 1
0
votes
1
answer
109
views
In Column Bucking strength of 24' 3"x3" Hollow Aluminum Tube with .125" Wall thickness
I am designing a Gin Pole to lift a 500# load. The pole will be hollow Aluminum tube 24'x3"x3" and .125" wall thickness pinned at both ends. The pole will be at a 45 degree with the ...
0
votes
1
answer
42
views
Aluminium tubing strength - size/thickness v length for supporting its own weight
I want to make a simple fruit picker for a tall fig tree. Most of the fruit is lost as it drops when ripe and explodes on impact with the ground below. That or the birds get to it before we do!
So ...
- 1
-1
votes
2
answers
90
views
Is ultimate tensile strength is constant for a material?
Is ultimate tensile strength is constant for a material? I have performed a tensile test of a frame tube and I made the dumbbell for tensile test.
The test specimen (A) has a thickness 2mm while test ...
- 57
2
votes
2
answers
213
views
Homogeneous materials and direction dependence of properties
A homogeneous material is a material which has a uniform composition throughout.
What do we mean when we say "uniform composition"?
I have learnt about pure substances in Thermodynamics ...
- 859
1
vote
3
answers
55
views
Why we needed to relate internal resistive forces with area (stress)?
When we load a body, say a prismatic bar, axially, internal resistive forces are developed within it to oppose the elongation or compression. What was the need of relating these internal resistive ...
- 859
0
votes
1
answer
157
views
Determining max shear stress
So I understand that shear stress can be either in the the form of transverse or torsional or both at the same time. And normal stress is due to the moment or a force normal to the surface. My ...
- 33
-1
votes
2
answers
146
views
Pressure vessel wall dimensions
I am trying to design a small cooling setup which has two parts: the compressed air vessel and the turbines. My understanding is that the compressed air, upon being released, passes through the ...
- 98
0
votes
3
answers
86
views
Economical difference with high-pressure vessel design pressures for fixed volume
Suppose space is not an issue and I need a fixed volume of compressed air (for storage), say 1m³. Is it more economical to manufacture a thick-walled vessel but with a smaller volume or a thin-walled ...
- 98
3
votes
1
answer
2k
views
Shear strength polymers
I was looking for some shear strength properties of common polymers/plastics.... I have not found any usefull information yet. I know polymers aren't that linear elastic, but I expected to find some ...
- 31
1
vote
2
answers
194
views
Trying to shed some weight on my design, any thoughts?
I am trying to design a lifting mechanism and I would love some insight/opinions as to how I can shed some weight off it.
The current weight I have for my mechanism is 187.5kg, however, this is ...
- 321
3
votes
1
answer
77
views
Contact stress of bearing surfaces
I am searching for information on how finite element code (abaqus /ansys) could be used to model the contact stress behaviour between 2 bearing surfaces?
The key point is that there is an additional ...
- 207