Torsion Definition and 237 Threads

Hi, Is there anything like adjustable torsion spring, even if it is non-helical spring based (such as say hydraulic or pneumatic). As in you can change their stiffness/spring rate? I know that there are so many videos on adjustable springs on garage doors but I think all they do is adjust...

Since the first day I learned the torsion I keep having the question how a nonvanishing torsion is likely to occur because based on the definition formula of the torsion, it looks like the torsion always vanishes. I have come back to think about this question a couple of times after my first...

In the presence of torsion, is it correct to say that the metric doesn't give rise to a unique connection? So, if we were using, say ECKS theory, which unlike GR includes torsion, in order to find the connection, we'd need not only the metric, but a specification of the torsion. My thinking is...

Hi, I am a bit confused. So I have a shaft with a step on both sides so it gets really large in the middle. I am trying to model torsion on the rotor of a BLDC motor with FEA (or by hand calculations). If I apply a moment on the sides and fix the faces at the end of the shaft I get 1 result...

I am NOT a physics major and clueless to figure out the strength of a custom spring I need to be made. I was hoping someone could help me, either with figuring it out, or turning me to someone/site that may be able to help. Here's the sitch': The spring is for a center kick-stand on a bicycle...

Hi all, In this article, page 7 - 3 there is a drawing of a Cylinder suffering Torsion. In the next page it says: ftp://www.bauwesen.fh-muenchen.de/Bauwesen/Konrad/Baustatik_1/Festigkeitslehre/kap07.pdf γ⋅dx = r⋅dϑ From my observations i come to tan γ=s/x ; tan ϑ=s/r ; therefore x⋅tan γ =...

I would like to know what makes a trebuchet better than a torsion catapult. I know that a trebuchet is more accurate and energy efficient but I am confused on why this is. I would be very interested to know all the details involved in both medieval devices.

Homework Statement Two axels of steel are connected with gears. Both axels have the same diameter (d) and length (1000mm). Diameter of gear B is 150 mm and diameter of gear C is 450 mm. Gear D is stationary. A torque of 100 Nm is applied to gear A.Maximum allowed shearstress in the axels are...

The orange thing is a gear being turned by a motor, which is intended to move the frame the shaft is fixed to. I realize the applied torque is going to create support reactions, but I can't quite figure out how to calculate the needed material strength so that the frame won't shear. All helps...

Urs Schreiber submitted a new PF Insights post 11d Gravity From Just the Torsion Constraint Continue reading the Original PF Insights Post.

I am trying to design a drive shaft that breaks when i apply a specific torque to protect fro over torquing. I made a few samples, and now i am trying to compare the results to my equations. My problem is, none of the equations seem to match the actual results. Your help would be appreciated: I...

Homework Statement A clock balance wheel has a period of oscillation of 0.250 s. The wheel is constructed so that its mass of 10.0 g is concentrated around a rim of radius 0.600 cm. a) What is the wheels moment of inertia? kg m^2 b) What is the torsion constant of the attached spring? N m /...

Good evening. I've got stuck in this question from my book of Mechanics of Materials by Beer and Johnston about torsion. The allowable shearing stress is 15 ksi in the 1.5-in.-diameter steel rod AB and 8 ksi in the 1.8-in.-diameter brass rod BC. Neglecting the effect of stress concentrations...

How do I find torsion constant (Kt) of a spring which is bent, as shown in the image below

hi, I looked up torsion tensor derivation on 2 different books, and encountered 2 different situations, so my mind has been confused. For the first image, I could totally understand how torsion tensor was derived, but for the second image although there are similar things, I can not make a...

Hi can anyone help me with this question on inertial forces in gears? Cheers Ali :)

why change of volume in pure torsion is zero? if you consider stress in plane with degree of 45 there is normal stress normal stress can lead to change of volume

So I've been studying advanced linear algebra and have started learning about modules. However, I am having a hard time understanding the difference between a zero divisor and a torsion elements. The definitions seem extremely similar. Can someone offer a good definition of each and an...

Dear All is the torsion always equal zero in supergravity? Thank you

Hi; I've been doing some research for my master's on gauge theory in the language of fiber bundles, and something occurred to me. Both GR and the Standard Model (SM) can be described in terms of connections (potentials) and curvatures (field strengths), but there's this generalization of GR...

The drive shaft of a truck undergoing acceleration twists a small amount. That twist defines a helicity. If you just know the rotation of a drive shaft you can not tell which way power flows but if given rotation and the twist of the shaft that can determine the direction of power flow? Thanks!

If the torsion of the straight line is undefined what happens with the information about the torsion? It is known (https://en.wikipedia.org/wiki/Quantum_no-deleting_theorem, http://van.physics.illinois.edu/qa/listing.php?id=24045) that the information conserved in a system can be nor created...

Homework Statement Given the period (T) and the moment of inertia (I), find the Torsion constant (K) T= 1.32s I= 0.0383 kgm^2 Homework Equations The Attempt at a Solution The answer is K=0.8678, I'm not really sure how to get the answer, but I think it has to do with the units.

Homework Statement Homework Equations T=(GJ/L)Φ G=modulus of rigidity J=polar moment of inertia L= length Φ=twist angle (rad) Direct shear = Force/Area Torsional Shear = Tr/J, where T is the torque and r is the radius from the center. The Attempt at a Solution G=11e6 KSI J=(π/16)d^4, where...

I've started f(T) theory but I have a simple question like something that i couldn't see straightforwardly. In Teleparallel theories one has the torsion scalar: And if you take the product you should obtain But there seems to be the terms like . How does this one vanish? because we know...

Would it be possible to write the torsion tensor in terms of the metric? I know that a symmetric Christoffel Symbol can be written in terms of the partial derivatives of the metric. This definition of the christoffel symbols does not apply if they are not symmetric. Is it possible to write a...

Hey guys. It's been a long time since I've done anything beyond a simple shear stress calculation, so have what will hopefully be a basic question. I've found similar examples but not ones I was confident I could apply to mine. As per the dodgey paint sketch I've made below, I have this...

http://www.upload.ee/image/4760492/DSC_0002.JPG Homework Statement I have given angle of twist, diameter, uniform load, and length of the beam. I need to find the G.The load gives me some trouble and i don't know if i should solve it by using integration or? :) Homework EquationsThe Attempt...

Homework Statement Actually I have two doubs, the first one is Why in the solution of this problem, in the sumatory of moments in C, Force 2=10?? If in the sumatory of moments in F, Force 2 is 416.7 N. Actually I calculate with 416.7 N, and T in C = 100 N. The other doubt is with the sign...

Homework Statement In the Cavendish experiment, the two small balls have mass m each and are connected by a light rigid rod with length L. The two large balls have mass M each and are separated by the same distance L. The torsion constant of the torsion wire is κ. b) Put the large balls a small...

I'm looking at 2 sources. One has it defined as ##T^{c}_{ab}=-\Gamma^{c}_{ab}+\Gamma^{c}_{ba}## And the other has ##T^{c}_{ab}=\Gamma^{c}_{ab}-\Gamma^{c}_{ba}## ##T## the torsion tensor and ##\Gamma^{c}_{ab}## the connection. Or is it more that different texts use different conventions? Thanks.

Hello lol first post . so I've done an experiment in determining the modulus of rigidity for a bar of an unknown material (torsion experiment). I have been asked to analyse the results, which I still have no idea what that means and find the material with the G value that i have. I've been...

I am having difficulties writing my damped oscillations lab report. We were asked to write a short essay on eddy currents (creation,direction advantage and disadvantage) and their relationship with torsion pendulums. Also,we have to explain if the copper wheel in the torsion pendulum could be...

Homework Statement if a vertical string hangs with mass M attached to its end and is twisted by angle (theta) then what will be the tension in the string 2. relevant equations T= mg torque= torsional constant x angular displacement 3. attempt to solution i am not able to start with...

Hello I am creating a torsional testing rig for a Formula Sae car, the front of the car will be pivoted about the center on a beam with the loading off to one side. In the design I need to calculate the deflection of the beam in order to determine which material and what profile of metal will...

Homework Statement A hollow pipe has an inner diameter of 80 mm and an outer diameter of 100 mm. If its end is tightened using a torque wrench using 80 N forces, determine the maximum and minimum shear stress in the material. Where are they located? Note: In the diagram of the picture, the...

I'm building a wall mounted cabinet, with a fold down door. It is for my grandson's slot car track, in his bedroom. The door is 3x7 feet and weighs approximately 40 lbs. It is mounted length wise, on the wall. I think I need tension or torsion gas springs, which pull instead of push. I don't...

I have a heavy door that I am adding torsion springs too in order to make it easier for a human to open. -The door weighs 460lbs. -It is hinged on one side by two heavy duty hinges and uses a thrust bearing in each hinge with a friction coef. of .008 -the effective radius of the thrust bearing...

Hello, I read in an article that in GR it is possible to use a connection with torsion to model ponctual particle with spin. The connection can be decomposed in a curvatue part and a torsion part. In an other part, we know that the invariance under pointcarré group imply conservation of spin of...

Hello I am a Junior Structural engineer and need to know how St Venant's torsion constant is calculated. It appears in structural steel tables, but without knowing how to calculate it, I cannot find its value for non-standard steel sections. Please, can somebody help. Regards Derryck

Hello! This might be a seriously obvious question but... if I were to wind up a torsion spring, such as the type found in a clock movement, and then not release it, how long could that energy stay stored? Presumably it depends on the material used but could it hold it's energy for...

Homework Statement I'm trying to find a relationship between spring and torsion constants for an experiment but am not sure what it is and am struggling to find it. Homework Equations Torque = Torsion Constant * Angle of Twist Force = Spring Constant * Extension Shear Modulus...

Hi, I'd really like to understand How a torsion balance works and exactly how You can use math to derive the Coulombs law. Is thre a good - realtively easy to understand - video or do someone have some good notes explaining exactly how it works? I'd really appreicate it.

how can we understand torsion of curve is in the direction of normal unit vector en?

Homework Statement The Attempt at a Solution http://imgur.com/3ZfjPxM.png So if you look at my attempt, I integrated the strain energy density function and at the end everything cancels out. Does anyone know what I did wrong?

I am struggling to make sense out some things. Hopefully someone can help or at least offer some different point of view. Let's examine a differential curve parameterized by arc length that maps some interval into an oriented surface (lets call it N(s)). The surface has a unit normal field...

"2nd tangential angle" and torsion When I derive dθ/ds I get the curvature k of a curve. But exist too the torsion τ of a curve and I think that exist some angle that when derivate wrt arc length s results in the torsion τ. So, is possible to define such angle...

I am trying to understand how to tackle torsion of bars that are non-circular and two-material composites. I understand the process of finding the torsion constant for non-circular sections but I am not sure how the warping function changes across a material interface. For example, if I have...

Hello I'm a student and I have project making a harvesting tool which need barrel cam I need force to cut trunk of coconut tree (I don't know it in english, what I mean is the hard part of coconut leaf) I'm a bit confuse here from Robert L Norton book Cam Design and Manufacturing...

I want to use a rectangular cross section to act as a torsion spring that can be adjusted. The idea is that the adjustment would be made via rotating the rectangular cross section about it's center at an angle theta. I've used parallel axis theorem before, but I don't think that is applicable...