Questions tagged [forces]
The forces tag has no usage guidance.
58
questions
2
votes
2
answers
57
views
Could moment be an imaginary concept?
In the figure above, a horizontal singular force is applied to a column from its end point. If we examine the column with the finite element method, we see that there are tensile and compressive ...
0
votes
2
answers
40
views
Axial force of cone on two rollers
I have a technical challenge, where I need to properly evaluate the axial force of the cylinder (D) rolling on two rollers (d).
Data of axial force is needed, because I need to properly design the ...
- 35
0
votes
1
answer
42
views
Harmonic drive motor output bearing specifications and bearing arrangements
I'm not a mechanical engineer, but I've been tasked with designing a system that uses a harmonic drive motor (specifically, a LynxDrive). It must rotate a 200kg mass, which is heavily off-center. It ...
0
votes
0
answers
29
views
Is the equation for the torque required correct?
Hey guys, I am working on a project in which 2 blades kept at an angle is used to cut stem of a plant. Rollers are used to pinch and force the stem towards the intersecting point of the blades. Lets ...
0
votes
0
answers
30
views
How to prevent rotation on axis with torsion springs?
I am trying to model a cupholder sizer for a Honda Odyssey, similar to what the Toyota Camry has (example).
I've got a basic design in Fusion360 using torsion springs. What I'm finding though is that ...
- 101
0
votes
3
answers
50
views
Help understanding why bending moment is integral of shear
I am aware of the basics of Euler-Bernoulli beam theory but there is one thing that I have never understood satisfactorily. Where $M$ is the bending moment, and $V$ the shear force:
$$\frac{dM}{dx}=V\,...
- 111
0
votes
0
answers
15
views
What is the correct equation for McKibben force output calculation?
I found this post, but no matter how many times I try, either in radians or in degrees, the results are simply weird.
My "correctest" result was -179533.
The dimensions are 100mm of length, ...
- 51
0
votes
0
answers
24
views
FInding deflection on a uniform beam with supports ~ Incorrect answer
Hello I am asked to find deflection of beam in millimetres at different points.
The uniform beam is 3.55 meters long with a flexural rigidity of 32269Nm^2
It is under a uniform load of 92N/m and is ...
0
votes
0
answers
41
views
Free body diagram problem: Linkage w/ magnets and friction hinge
I am a bit stumped on a IRL problem, which i simplified in the diagram below:
There are left and right beams (gray) linked together by a friction hinge. The bottom beam (black) is connected to the ...
- 21
1
vote
0
answers
38
views
Optimizing the layer lines of a 3d printed part, based on subjected forces
I was directed here from the 3d printing stackexchange...
For years I have been fortunate to only have had to make 3D prints that don't require a large amount of force on them. But recently (since ...
0
votes
2
answers
61
views
Is it possible to simulate inertial load using brake?
Suppose to have an engine attached to a flywheel, I add power, the flywheel start to rotate and oppose a resistance to motion. More power, more resistance.
I'm wondering if I can simulate this ...
0
votes
1
answer
42
views
When something undergoes angular acceleration (like a bar) how does the distribution of forces look along the bar?
This is something kind of explained with propellers and turbine blades but I'd love some good explanations. Thank you!
0
votes
3
answers
115
views
When a catapult is cocked back, is the energy stored primarily in stretching of the rope, or bending of the wooden frame?
Referring to an onager or catapult like this:
I searched it but couldnt find a good answer. I believe that theoretically it could work either way. Likely its at least a little bit of both, but where ...
Drew♦
- 1,991
2
votes
1
answer
230
views
How do I relate tongue weight to weight x distance?
The specification for car hitches routinely state the tongue weight, but do not specify how far that weight can/should be applied. What am I missing? Shouldn't the maximum bending moment be the one to ...
- 441
0
votes
2
answers
309
views
What Tension Force will make the bolt to pull out of the nut?
I know how to calculate the bolt capacity for tension and shear, also how to check bolt bearing against different elelment such as steel or aluminum.
There is a hanging bolt by which a bar is hanging ...
0
votes
0
answers
17
views
What forces act ona key in a shaft during the work of spur gears?
What forces act on a key in a shaft during the work of spur gears? Are the forces which act on key only from the torque of shaft or also forces from gears mesh and work?
- 1
0
votes
4
answers
60
views
Why does restoring force of a spring vary directly with elongation or compression?
The restoring force is electromagnetic in origin, having to do with atomic/molecular interactions. Both electrostatic as well as magnetic forces vary inversly with the square of distance. $F_{_{EM}}\...
0
votes
1
answer
575
views
Calculating forces of TV wall mount with long extended arm. Need help with Physics, torque vs force and anchor requirements
I'm planning to install a wall-mounted TV with a very long arm on a plasterboard wall, although conventional wisdom advises against it. The TV mount is 45cm wide with holes for 6 screws. To address my ...
- 101
0
votes
1
answer
35
views
structural engineering - calculating moment & shear forces for a custom floor mounted hangman's style heavy bag stand?
I own a martial arts facility and I have a few hangman's style (single arm) heavy bag stands that a fabricator friend made for me. These will be used to hang 6' heavybags (100lbs each) attached to a ...
- 1
0
votes
0
answers
43
views
Practical question on force in a molding application
I have a molding machine that is holding a spring loaded mold closed. The mold is basically two blocks of steel, but one half has a slide system that is pushed open by a number of gas springs. Those ...
- 1
1
vote
0
answers
85
views
How to calculate force / torque between permanent magnets
Given two permanent magnets (for instance, made with ferrite or neodymium with shape of: cylinder, disc, toroid, etc), how can I calculate the force / torque between those magnets? Are there any ...
0
votes
1
answer
24
views
Is this axial load or radial load
I am confused by Axial loading mentioned in the figure below. The long black line is a piece of rubber passing over different rollers. And at the point "Axial Load" a weight is attached. The ...
1
vote
1
answer
73
views
Hertz contact pressure formula for cone on a plane
Can anyone please point me to some literature that contains formula for Hertz contact pressure for conical body on a plane? I know that there are general solutions that probably cover also this, but I'...
- 35
0
votes
0
answers
125
views
Find the Angles 1 to 3 so that the Reactional Forces Become Minimal
My question regards the following system:
This system is supposed to be located in a plane, so it is 2-dimensional.
It consists of three rods, which are connected at the ends. Meeting in the hinges $...
2
votes
2
answers
129
views
Passive mechanical element that can act as counterforce for a spring
An elavator is a moving cabin that gravity acts on. On the scales of the typical elevator application (a skyscraper for example), gravity is constant. So the gravitational force can be counteracted by ...
- 163
1
vote
2
answers
147
views
A question on understanding the nature of static equilibrium
In the statics lesson, we do not think about the effects of forces on objects. In other words, we do not assume that an object can break, bend or twist. In the same situation, we can combine different ...
0
votes
1
answer
167
views
Understanding the nature of Force and Moment FBD diagram
Hello, I am Civil engineer Bilgehan Yılmaz.
First of all, I would like to ask a question about basic statics, I modelled my question below. The following forces are applied around a wooden stick with ...
0
votes
1
answer
221
views
Moving internal forces for the sake of stress
I am studying mechanics of materials and I'm confused with determining internal forces for the sake of stresses.
Consider this diagram: (just for visualization. from Beer Johnston book)
when ...
0
votes
2
answers
240
views
How to calculate stiffness to weight ratio of one big tube vs two small tubes (see drawing)?
How does one calculate the stiffness1 of (a) one big diameter tube and (b) two small diameter tubes that are a certain distance apart?
I have made a drawing that illustrates and specifies the question:...
- 23
0
votes
1
answer
277
views
How to calculate force acting on axle from hub motor with known torque?
In some electric bikes, a motor is mounted to the hub of the front wheel. When turned on, this hub motor applies a torque, turning the wheel, reacting against the ground, with a resultant force acting ...
- 103
0
votes
0
answers
49
views
Truss beam like structure strength per height
The second beam is 2x the height of the first one.
Is 1 stronger then 2 to bending force (arrow shows direction, supported on the sides)?
If it does, I'm trying to figure out why, because they both ...
- 115
0
votes
2
answers
108
views
Is a centrifuge force-based levitation system operable in the real world?
In the sci-fi comic Betelgeuse, the artist Leo presents a flying car with an unusual system for levitation and propulsion. The interesting point is that at the end of the comic, there is a page on ...
- 161
0
votes
0
answers
49
views
How to calculate the force required to move this pawl that swings on a pin?
The structure (pawl) is rotating about a pin and is pushed forward by a spring. I want to calculate how much force it requires to push the pawl forward with the spring. Since the spring is only ...
0
votes
1
answer
45
views
Torque created at bottom left corner due to torque in centre of 2D box
If I have a 2D box with uniform mass of width $w$ and height $h$. I apply a torque $\tau_O$ to the centre of the box, labeled $O$. The box has a fixed point $A$ at the bottom left around which it may ...
- 1
0
votes
1
answer
101
views
How to calculate the mechanical advantage of torque reaction arms (or balanced articulated arms)?
So, I was trying to figure out how to figure out how much force I would need to apply to these articulated arms in order to make them extend or "contract", but I can't figure out.
I tried ...
- 51
-1
votes
1
answer
54
views
What is the name of the type of diagram that displays all the forces that act on a moving bicycle so that it stays in balance and does not fall?
If I were to draw a diagram the system of forces acting on a bicycle at high speed in order to demonstrate that the bicycle does not fall over, what is tat type of diagram called?
0
votes
1
answer
54
views
Calculating forces on cables
I have to calculate the pull forces of Fab and Fac.
I have used extended Pythagoras to find the length of AC and AB but I have no idea how to calculate the forces. I also tried to use cartesian ...
- 3
1
vote
1
answer
265
views
How to calculate the volume of a partially submerged horizontal cylinder and the center of buoyancy?
I was wondering how it was possible to calculate the volume of partially submerged horizontal cylinders and the center of buoyancy considering that these horizontal cylinders are just the supporting ...
- 11
0
votes
0
answers
35
views
Preventing u- tube effect on a fluid
Say you have two cylinders, one fixed bigger outer cylinder and the other is free (lets say a straw with a tapered end 1/3 from the bottom. As you push the straw into the medium (fairly dense viscous ...
- 1
0
votes
1
answer
29
views
Why Do the Fingers in Mechanical Pencils Fly Out?
In this video(https://www.kidzsearch.com/kidztube/watch.php?vid=65fbcb9ca), at timestamp 0:27, it says that in mechanical pencils, the fingers have a taper in them that results in them flying out ...
0
votes
1
answer
91
views
Distributing force over multiple springs evenly
I am trying to build a big push button in the shape of a rectangle. I have 4 springs at each corner (below the plate), but the problem is, that because of button's size, if I press down on one of the ...
- 1
0
votes
0
answers
422
views
Calculation of Cutting forces (tangential , feed and normal) in CNC Milling Process
I am doing my fyp project on 5 axis cnc milling machine.I need to calculate forces on each axis as mentioned in the below picture
I first calculated spindle power from https://www.machiningdoctor.com/...
0
votes
1
answer
240
views
Finding hoop stress in a half-cylinder
I have a half cylinder which is significantly thick but not very long. In the half cylinder, a force $F_{app}$ is being applied over a certain area as shown in the figure below:
I have to find the ...
- 13
0
votes
1
answer
119
views
Angle of attack for torque calculation from buoyancy force
To calculate the torque caused by the buoyancy force I need the length and the angle but what angle should I use? Should I use the angle of from the center at the bottom of the angle from the center ...
- 7
0
votes
0
answers
222
views
Do automatic quick release mechanisms exist?
I'm imagining something like a cable tie that would automatically release after a certain amount of tension was applied.
I guess a very basic way to do it would be to use different diameter strings ...
- 101
0
votes
1
answer
50
views
center of mass of rotating rod system
I have a system with a rot connected to a motor and I need to determine the center of mass to calculate the moment caused by gravitation.
To illustrate:
I am uncertain about how to do this, is it a ...
- 51
1
vote
2
answers
324
views
Dynamic forces in Simulink
I have the equation of motion:
$a = \frac{1}{m} \left( F_1 - F_2 -F_{fric} \right)$
where a is the acceleration and m is the mass of an object. $F_{fric}$ is the friction calculated as:
$F_{fric} = B \...
- 51
0
votes
1
answer
53
views
Movement caused by buoyancy
I have a rod that can rotate about a point, the rotation is caused by the buoyancy of 3 balls connected to the rod as in the picture:
I need to calculate the angle at different heights and the ...
- 51
1
vote
2
answers
1k
views
Calculate compressive stress in shaft/key surface from torque
When designing shaft keys we calculate compressive stress in hub/shaft/key and compare it with allowable stress. The usual formula is
$$p = \cfrac{F}{A} = \cfrac{\cfrac{M}{R}}{L_e \cdot t}$$
where $p$ ...
- 13
2
votes
1
answer
151
views
What is the force required to puncture through a sheet of foil against an anvil?
A hardened steel contour with a sharp edge presses against plastic foil which lies on top of a hardened steel anvil plate. What would be the force required to punch through the foil?
I am familiar ...
