Beam Definition and 1000 Threads

Is anyone familiar with the Roark's text that can clarify some terms for me? I am trying to clarify what Roark is referring to in the above mentioned text in the section on short beams (in the 5th edition 7.10 and in the 7th edition 8.10). Throughout the text, he uses the terms "span" and...

http://www.personal.psu.edu/kar5230/blogs/kyles_professional_portfolio/How%20to%20Design%20a%20Singly%20Reinforced%20Concrete%20Beam.pdf I'm stuck with a formula above. It says that to calculate for Moment of a beam... use the formula Mu= w L^2 / 8 now given w = 1000 lb/ft, L=20...

Homework Statement The maximum depth of Lake Baikal, in Russia, is 1780.7 m, making it the world’s deepest freshwater lake. If a beam of light with an angle of incidence of 59.42o enters the water from the air, what is the horizontal distance between the point where the light enters the...

Homework Statement The Attempt at a Solution So I noticed the units of w_0 were in N. In other words to find the moment I would have to integrate 100∫01 x2+1-2x dx. However I ended up with the wrong answer. The correct answer requires that I integrate 100∫01 x2+1-2x x dx...

Homework Statement As shown, a roller at point A and a pin at point B support a uniform beam that has a mass 25.0 kg . The beam is subjected to the forces f1 = 50.0N and f2= 79.0N . The dimensions are l1= 0.750m and l2= 2.30m . (Figure 2) What are the magnitudes and of the reaction forces...

Homework Statement Find the maximum deflection in the beam. E=205Gpa Beam breadth = 195mm UDL on beam: 40 Bar Homework Equations I have useed the method of superposition to try and solve it. Is this the best way? It has been suggested that finding the displacement by integration would...

Homework Statement Hi i have been doing some hand calculations, for an assignment, I have an unsymmetrical L-section beam and trying to find out the natural frequencies for the beam, axial and torsion. I have attached the formulae i have and what i have worked out for the areas of the...

How do I find reaction for loading condition shown in image. I have no idea how to tackle this type of problem. Please help. http://img6.imageshack.us/img6/725/partilaudl.jpg Uploaded with ImageShack.us

Hi friends. Does any of you knows anything about the beam line design tools ? I mean which program could be used to drow an electron beam line of a free electron laser from the gun to the dump ? Each device have to be indicated by name and with some other properties. The diagram must be...

Okay, I have the following scenerio (attached picture). The inputs for path b and c are two photons. both photons aren't entangled with each other - they're entangled to other photons. Before the beam splitter there is a wave plate that converts the photon into the 45/135 basis. So what we...

If I have a wide beam, parallel to the x axis, with its COM at the origin, then I want it to curve about the y axis, what would the elements of the strain tensor be? I have come to the conlusion that the beam would, for example,contract above x-axis and expand below it. But I don't know how...

Hi Guys, Do you know of any short formula to calculate bending moment of the beam on the attached image? I need to know the force at which this beam will start bending.

Are there any labs or private companies that can run particle beam simulations for a fee? If there are, any suggestions how to find them? thanks..

I'm doing some work on my house at the moment, and have had a design produced by a structural engineer for a steel I-beam to span a newly made (4 meter) opening in a brick wall. They've given me a design (see the attached picture for my interpretation) for the bearing of the I-beam which I...

Problem and Solution (albeit to a beam of different length L) provided in attachments. Hi, I have been able to follow the provided solution to get the moment equations and understand the x1 and x2 positional references etc. I also understand that integrating the moment equations provides the...

The attached question shows a simply supported beam with a UDL of 30kN/m and has a rigid arm underneath with a load. This question was a research one but unfortunately I have had no luck. I thought that this could be solved by doing moments for the arm but am unsure on whether that would...

Homework Statement Calculate the deflection of an electron beam as it passes between the plates of a CRT tube. In the picture, the parallel plates create an electric field, with the positive plate on top and the negative plate on bottom, causing the electron's path to be deflected upwards as...

Hi all. Let's say I want to reproduce the support conditions for a beam. The easiest one I could think of is fixed end. Like I hammer an end of the beam into the wall. This represents fixed boundary condition. Likewise can anyone point out how to reproduce Simply supported end condition in...

Hello For my dynamics I had been going through some examples and verifying them using Staad Pro. However, I been having issues with some of the examples as some do not show the full detail of calculation description. The one example been having problem with is where you must calculate the...

This is for a deck: Which beam is stronger? A) a beam with cross-section dimensions 4"x10" and 8' long B) a beam with cross-section dimensions 4"x12" and 12' long Both beams are same material and are both simply supported at the ends. Same load type (either concentrated or distributed...

It’s clear that bending moment for a curve beam is less than straight one And you can attribute this to moment of inertia, but there is something i don’t understand Which is if i have straight beam with small moment of inertia or huge moment of inertia simple supported beam), the moment will...

what is meant by the term "beam spill"? in the context of a beam of particles from an accelerator?

Hello. Lets say we have 2 small holes (1&2) which makes tiny light beam from the Sun's light. (similar to laser beam) ......1|......|2... (Sun) -> >-------------------------------------|dg|-----{order 0}-------(Earth) ......1|......|2... |dg| is diffraction grating perpendicular to the light...

My main question is why we derive the structure matrix for a beam like the attached first picture; we assume the beam on the left on point B has no deflection? While i check this by computer analsysis program and it has an effect. Please explain in details The second question is the...

I am just curious, for nuclear power plant or nuclear weapon/detonation, how to create a beam of neutron that's energetic enough to go inside the U-235 atom and trigger the chain reactions? What was the most conventional or the oldest way to create this beam of neutrons in lab back in the...

Is it ok to use anodized aluminum with anolok (dark brown) finish to terminate laser beams? Most use black anodized aluminum, but can the former be used instead?

Homework Statement Calculate stress in a curved beam and compare with FEA model. Homework Equations Stress = (M*(r-rn))/(Aer) The Attempt at a Solution I used the above formula, which is repeated in many textbooks and reputable engineering websites, to calculate stress in a...

Homework Statement As shown in the attachment, a free body diagram (FBD) must be drawn Homework Equations sum of horizontal force = 0 sum of vertical force = 0 The Attempt at a Solution 1. Forces F1 and F2 appear exactly as they are in the FBD 2. At point A, there is an outward horizontal...

A 1 Gev/nucleon ion beam strikes typical matter ... In this thread: https://www.physicsforums.com/showthread.php?t=622502 the key to figuring out what will happen would seem well modeled by any study or analysis of a 1 Gev/nucleon ion beam striking matter (e.g. a baseball). The density...

Is it possible to split a single light beam into two beams of opposite circular polarization? A properly oriented calcite crystal will separate a unpolarized beam into two beams, one vertically polarized and one horizontally polarized. Other polarizers pass just one polarization and absorb...

Homework Statement A beam has a solid square cross section of 100mm and is simply supported by two supports 3m apart. Calculate the dead load that can be safely supported when applied to the middle of the beam. Homework Equations Solid square cross section of beam: 100mm Material...

Hello everyone, I have a question regarding the moment and deflection calculation of this handrail beam that I have. I am attaching a picture to give you guys a look at what I am working with. The hand railing is 4" x 4" and it is not attached half way, its just resting on that beam, it...

Most of the applications requiring small diameter laser spots are generated by focusing of laser light and that has a theoretical diffraction limited minimum diameter equal to the wavelength. Does anyone know what is the smallest fully collimated beam (small divergence say single digit milli...

In the tank building industry some pressure vessels use curved pieces of flat bar, welded to the tank, to protect nozzles in the event that the tank rolls. I'm trying to determine how thick the flat bar should be for a given length so that it won't bend too much and allow a nozzle to be damaged...

If we consider two laser beams with identical 3 level energy level schemes except that the metastable state for one has a lifetime of 1μs and the other, 100μs. Which will give the brighter (more intense) beam? I gather that, since all things are identical up to the metastable state, the...

Hello Phys Forum I’m trying to solve a dynamic problem that involves a cantilever beam fixed onto a support that experiences a time history load on the free end of the beam as shown below: / / /--------------------------------[] / / Cross section Beam is rectangular beam with 1m width and...

Just want to ask if the moment diagram of Cantilever beam with fixed end at left is the same as with fixed end at right. What I mean is that they are just mirrored ? Thanks

Homework Statement a cantilever beam 5 m long with a mass of 100 N/m carries a concentrated load of 1000 N at its free end. The end of the beam is inserted into a wall 0.5 m thick. What are the reaction on the beam. Homework Equations The Attempt at a Solution My problem is I...

Are there any structural engineers here or know the stuff. I'd like to know this. Can structural engineers design long span beam for example 12 meters reinforced concrete beam that is as good as standard 6 meter beam in seismic performance or are 6 meter beams always better compared to 12...

This is just for fun so don't take it too seriously... So I've read about particle beam weapons and as far as I understand its simply a concentrated beam of particles ie electrons emitted towards an object. I'm pretty sure I'm missing a big piece here when I say it (it just sound too easy) but...

Homework Statement A beam has a solid square cross section of 100mm and is simply supported by two supports 3m apart. Calculate the dead load that can be safely supported when applied to the middle of the beam. Homework Equations Dead Load= volume * weight of material The...

So I am trying to figure out how I can calculate the deflection and ultimate bending moment capacity of a hollow tube beam when the hollow portion is not concentric. A regular concentric tube is easy enough but this has me out of my depth. I assume that it will no longer be symetric in its...

Consider a light beam has a mechanism,say by some unknown virtual particles like tachyon or etc(like we use light beam to observe other things)...Or some mechanism to observe other light beam,then will the other beam of light move at speed of light for it too.? And also taking relativity...

Hi All, Protons repel each other and in order to make them collide in the LHC huge amounts of energy have to be put in place, my question is; if we launch a beam of electrons transversal to the beam of protons and right in the collision point of the protons, would not this increase the energy...

I just want to know the relationship between beam depth and column size. I know there is a relationship. But in uniform loading, do they increase beam depth or column size? or rather.. would increasing beam depth and keeping column constant be able to handle more load? or should the beam depth...

Hello everyone, I am an undergraduate student studying lasers. I have hard time to comprehend why does the beam diffract upon leaving the laser, does it have something to do with the wavefront being limited in size? Can you explain why does the following formula exists and how is it derived...

Homework Statement Dense No 1 grade of Douglas Fir-Larch, 6x12 is to be used as a simple beam spanning 10 feet with a 2 feet overhang. The beam has the loading shown in the sketch I've attached. Determine the maximum value of the concentrated load "P" to maintain the structural integrity...

Hi, I'm looking for a parameter or a design guideline that could say weather or not the classical bending theory can be applied to certain beam under certain load. I'm making my dissertation about some work on cantilever beam and it's first natural frequency, so in order to model correctly...

Hi there, first post on these forums. I have a seemingly simply question about beam bending. We (mechanical engineers) are all very familiar with the standard beam bending scenario. The beams are always shown being loaded perpendicular to the neutral axis, regardless of the type of support...

I've been reading through my mechanics of materials textbook recently, notably in regard to the section on the deflection of beams. The well regarded Euler-Bernoulli beam theory relates the radius of curvature for the beam to the internal bending moment and flexural rigidity. However the theory...