Beams Definition and 274 Threads

  1. S

    Simply supported beams bending moment

    I don't know how to do the following question, The beam shown is under the action of a uniformily distributed load w of 2 kN/m between the supports and a point load of 2 kN at the end point. Determine the bending moment in kNm at point A situated 3 m to the right of the left support. Round off...
  2. marcus

    19 March LHC gets 3.5 TeV in both beams, a first.

    http://www.math.columbia.edu/~woit/wordpress/?p=2819 ==quote== High Energy Beams at the LHC At 5:23 am in Geneva this morning, for the first time the two LHC beams were ramped up to high energy, the 3.5 TeV/beam that they plan to run at for the next two years. These are the highest energy (per...
  3. L

    Measuring Laser Beam Intensity: Techniques and Equipment

    Can anyone tell how the intensity of lasers beams is measured. What equipment is used. Any relevant equations?
  4. M

    Solid Mechanics: Cantilever Beams & Loads on Neutral Axis

    Hi, In a cantilever beam with a load on the free end, at a point on the neutral axis, will the normal stresses (due to bending stress and axial stress) be zero? Or am i wrong? And if i was to draw a Mohr circle for that point at the neutral axis, would the center of the circle be the origin? I...
  5. M

    When 2 particle beams meet head on

    When 2 particle beams meet head on, more energy is avaliable than when the particle beam is directed at a fixed target. Why is this? My textbook gives an explanation which I don't understand, involving rest mass energy. Any alternate explanation or explaining the one given will be great...
  6. D

    Find Ratio of d/b for Minimum Stress in Beams & Bending

    find the ratio of d/b such that the largest stress in the beam will be minimum i know that the maximum stress is σmax=Ymax\frac{M}{I} and i know that for a rectangle I=bh3/12 now in the question i am asked to find the ration of the (diameter of the log)/(the width of the rectangle) such...
  7. A

    General Questions About sizing Structural Beams.

    General Questions About "sizing" Structural Beams. Hello Guys. I would like to know where I can find high quality info on which types of beams to use for certain applications. Say, for example, a 100 foot span which is supposed to hold 100 tons at the center, or cantilever, and so on. I know...
  8. M

    Ideal destructive interference of two beams - Where is the energy?

    Two perfectly coherent laser beams point at two different positions on a screen. The energy transmitted by each of the beams is dissipated at the screen - it's either reflected (and thus visible to an observer) or becomes a potential energy of some sort. Now both beams are pointed at a single...
  9. Vanadium 50

    LHC Re-establishes Circulating Beams at CERN

    Last night the LHC re-established circulating beams. CERN has issued a http://press.web.cern.ch/press/PressReleases/Releases2009/PR16.09E.html" .
  10. J

    Finding Reactions In Simply Supported Beams

    Homework Statement Hope you can access this link for question http://s353.photobucket.com/albums/r387/james_nikko/?action=view&current=img002.jpg Supports are at 1.5m and 4.5m Homework Equations The Attempt at a Solution Ok so i have attempted the problem using the following (5x1.5) + (5x3)...
  11. M

    Deflection of Beams - Rearrange formula

    Deflection of Beams - Rearrange formula [URGENT] Homework Statement Deflection for a simply supported beam... I calculated the deflection of it to be 9.72mm downwards, but there is a support 6mm from the original position and need to calculate the force on the support... The original...
  12. P

    CM energy for different mass/energy beams

    Dear Particle Physicist, I'm unable to find an equation for the CM energy to use for when colliding beams have different masses and energies, for example the HERA colliding electron beams with proton beams. If you know a website, and can write the equation I'd be grateful. Thanks in advance
  13. M

    Mechanics of materials ques / stresses in beams

    Homework Statement refer to attachment Homework Equations The Attempt at a Solution I am completely confused at where to start can someone get me going in the right direction here as to one of the answers.
  14. S

    How Much Bending Moment Can a Plyweb Beam With Timber Flanges Carry?

    Calculate the maximum B.M the symmetrical section can carry Plyweb with timber flanges (50x100 c.s.a) The maximum stress = 1.0N/mm^2 The structure is essentially an I beam with dimensions as follows. The central beam has a width of 25 and height of 500. The four flanges which...
  15. A

    Particle beams in space rockets

    I'm currently working on a new paper on how to increase the efficiency of space rockets (both in performance speed and power). Getting the idea from a simple CRT (Cathode ray tube) and how the beams make an object move in the tube; I came up with this idea to use the same thing in a typical...
  16. E

    Calculating Reaction Forces and Maximum Bending Stress in Simply Supported Beams

    simply supported beams? [b]1. Can anybody help me? please. This seems like I have gone completely off track. A simply supported beam of length 6m supports a vertical point load of 45kN a distance of 4m from one end. If the maximum allowable bending stress is 120MPa: (there were 4 previous...
  17. L

    Question involving load on beams

    Hey, so there are three loads on a beam the units they are is in pounds (i.e. 7200pounds is one of the loads). There are two cases each for which I need to calculate reactions and draw bending moments and a sheer force diagram. The PDF attachment contains the information in more detail help...
  18. J

    How far from the entrance will the beams of the different isotope ions end up?

    Homework Statement There are three main isotopes of carbon, with the following atomic masses: Atomic Masses 12^C 1.99 x 10^-26 kg 13^C 2.16 x 10^-26 kg 14^C 2.33 x 10^-26 kg The atoms of carbon are singly ionized and enter a mass spectrometer with magnetic field strength B = 0.200 T at...
  19. ZapperZ

    Accelerator and Beams - Tools for Discovery and Innovation

    The Division of Physics of Beams of the American Physical Society (APS) has produced this wonderful brochure titled "http://www.aps.org/units/dpb/upload/brochure.pdf" ". It essentially describe what a particle accelerator is, and more importantly, what it is used for. The main purpose here is...
  20. J

    Question:Parallel capacitors and electric beams

    An electron beam is send perpendicular onto an electric field between two capacitor plates. The electrons got their kinetic engergi by being accelerated through a potential difference V. The potential difference between the capacitor plates are also V. The distance between the plates is d, and...
  21. J

    How do I calculate radial stress in a u-shaped t-beam with varying thickness?

    I have a u-shaped t-beam, and I am trying to calculate the radial stress where \theta=0 degrees. I have calculated \sigma\theta_{} but I am unclear on how to treat the varying thickness of the cross-section when integrating with respect to radius.
  22. A

    What is the Deflection of a Simply-Supported Beam?

    Homework Statement Deflection of simply-supported beam problem. Please see the attached image of an example problem from a textbook: http://img14.imageshack.us/img14/619/hearnbeamproblem.png I have absolutely no idea why A = - (wL^3)/24 and why 0 = (wL^4)/12 - (wL^4)/24 +AL is used in...
  23. C

    How Is the Deflection Formula for a Simply Supported Beam Derived?

    Hi,:smile: I am only new to this forum so any feedback would be greatly appreciated. I am wondering if anyone could help me derive the formula for a simply supported beam with a uniformly distributed load. I understand that it is done using integration but I fail to understand the steps...
  24. A

    Composite beams and young's modulus

    Homework Statement "A polymer, with Young’s modulus 2GPa and yield stress 50MPa, is reinforced by uniaxially aligned glass fibres which have Young’s modulus 70GPa and fracture at 1400MPa. The volume fraction of fibres is 40%. (a) Calculate Young’s modulus for the composite in the...
  25. R

    Young's double slit experiment beams

    Homework Statement In a Young's double slit experiment, a pair of slits is encased in a rectangular block of glass (n=1.52), and glass block is surrounded by air, as shown below. The glass block is illuminated by coherent light (k = 660 nm) from a laser, as shown. The beam enters the block at...
  26. P

    Help with Solid Mechanics Assignment: Stress, Deflection, Beams, Macaulay's

    i have an assignment due this thursday, it has 9 questions, i was able to solve five of them. but for some reason i missed most of the classes in second term so i don't understand anything about the last four questions. the questions are: Question 1: A beam is simply supported and loaded...
  27. C

    Superposition of two laser beams

    I want to superpose two laser beams to create the beat frequency. I design the system to be like this . Two laser beams come from A and B meet at the center of the PBS, so that two laser beams going out to C and D. I tune the laser beams A and B such that the laser output at C and D...
  28. B

    Bending of Beams - Deflection - Stress - Strain

    Homework Statement A beam of lengh is supported in a clamp system. distance between clamp is 1m. Loads applied at 250mm and 750mm. strain gauge fitted at 175mm with 100ohm resistance. Weight is applied at points a and b. Homework Equations Dont know? The Attempt at a Solution I...
  29. S

    Is there a weapon that beams particles like a taser?

    My friend insists she is being "hit" with something that causes her pain. She has no diseases that would cause the pain. At first I thought she imagining things but after further investigation, there are reasons to believe her. She said she saw three different persons have a baton or wand which...
  30. P

    Two coherent beams crossing each other's path; what will be the effect?

    A laser beam is split into two beams. After traveling some distance they cross each other's path. I was just wondering this crossing will have any effect on the beam properties or not. More basically, if two coherent beams one heading north and the other heading east cross each other at origin...
  31. T

    How Far Can Chris Walk on a Cantilevered Beam Without Tipping?

    Homework Statement Chris and Robin use a 3m, 40kg, plank to span 2m over a river. The plank is set up with 1.0m on the bank and Robin is standing so that her centre of mass is 0.2m from the end. The diagram attached shows Chris (50kg) walking out on the plank. Robin has a mass of 80kg...
  32. J

    Possible to make 2 beams of light cancel?

    Last night, I was doing some really cool stuff with light interference, like the double split experiment and such. so, then i started wondering, is it possible to make 2 beams of light from different sources cancel each other out? [see attachment (gray are represents steam or something to make...
  33. L

    Calculating Deflection and Shear Flow in Riveted Beams

    Homework Statement A beam loaded by a central point load deflects a quantity, e.g. d. If an identical beam is laid on top of the first beam and the same loading is applied the deflection drops to d/2. In this loading situation the ends of the beam are not aligned. When the beams are joined...
  34. P

    So structural beams are used pretty much everywhere right?

    like everyday homes and highway bridges and almost every other building right? just making sure... I mean, I've never actually seen an everyday home being built and you can't see them just by standing inside the house.
  35. W

    High-Energy Beams: Finding W & Z Bosons

    I read on http://cern-discoveries.web.cern.ch/cern-discoveries/Courier/HeavyLight/Heavylight.html that to find the W and Z bosons they used beams with 270 GeV of energy per beam. But the W and Z bosons have a mass of about 80/90 GeV, how come so high-energy beams was needed?
  36. J

    Arches or Beams: Why Arches Hold More Weight on Pasta Bridges

    Why do pasta bridges made with arches or triangular peaks hold more weight than those made with a flat beam? Assume the weight is attached to the base or deck of the bridge.
  37. R

    Why Are 1.2m and 0.45m Unnecessary for Determining Force F?

    In the attached diagram, if the beam was not undergoing any rotation would this be because the couple C1's forces are being canceled by the x components of the forces F and -F and also because the y components of the forces F and -F are canceling each other out? So if C1 was known and the F...
  38. J

    Two oposite beams and earth and rocket again

    I am sure this question in some form gets posted here all the time again and again, but I somehow can not find it in the form I would recognize, so my appologies for probably posting it again. So one of the classics: Two light beams - A and B get launched from Earth to the opposite directions...
  39. P

    Help for project looking into the amount of load's beams can take

    Hi guys I was wondering if you could help me out with designing a project. I am looking into how much load different beams can take. How should I weigh down the beam? Should I put load on top of it or hang it from the bottom, or something else? If on top, should I just load it all directly on...
  40. E

    How To Apply Reciprical Theorem To Beams

    I am trying to learn and figure our the reciprical theorem when applied to beans and the deflection on a beam when a load is applied. The beam would be x long, say 10m and would have a weight/load applied at 5m, or dead center. There would be point A (Dead Center) point B (Half way between...
  41. E

    Using Reciprical Theorem With Beams

    I am trying to learn and figure our the reciprical theorem when applied to beans and the deflection on a beam when a load is applied. The beam would be x long, say 10m and would have a weight/load applied at 5m, or dead center. There would be point A (Dead Center) point B (Half way between...
  42. E

    How Does the Reciprocal Theorem Apply to Beam Deflection?

    I am trying to learn and figure our the reciprical theorem when applied to beans and the deflection on a beam when a load is applied. The beam would be x long, say 10m and would have a weight/load applied at 5m, or dead center. There would be point A (Dead Center) point B (Half way between...
  43. F

    Calculating Torque T & Q for I-Beams & Torsion

    You have two parallel I-beams. A trolley with 4 wheels runs on top, and carries a total load of say 10kN. How would you evaluate the torsion? angle theta = TL/GK where (for an I beam) K = [2bt^3 + (d - 2t)(thickness of web)^3] / 3 and t = thickness of flange But, how would you calculate...
  44. P

    What happens when two light beams collide ?

    Iam very new to this forum. I just had this doubt for the last week. pardon me if this is a silly one. the doubt is : what happens when two light beams traveling in perpendicular directions collide ? collide in the sense i mean what happens at their intersection point ? what i have...
  45. Q

    Hollow sphere or sphere with beams

    A friend and I debated what is the 'stronger' structure: a hollow (fluid filled) metal sphere or a metal sphere with one or more metal cross beams that span the sphere diagonally given that the same quantity of material is used in both. By 'stronger' I mean the resistance to compressional forces...
  46. W

    Calculate Min Drum Diameter for Copper Strip 4mm Thick, max Stress 332MN/m2

    Homework Statement 3. Calculate the minimum diameter of drum on which copper strip 4mm thick may be wound if the maximum bending stress is not to exceed 332MN/m2. Assume E = 95 GN/m2 σ /(yxE)=r Homework Equations The Attempt at a Solution would this work if so i make it...
  47. F

    Statics- beams internal effects i dont get it

    Homework Statement this is a picture of an example from the book. I am going off of it to solve a problem that will be on my test tomorrow. i can figure out how to calculate the shear force and moment of each section (though i don't fully understand it), but I am just not getting how they...
  48. M

    Shear Forces and Bending Moments in Beams

    Homework Statement (Q) A beam 4m long is supported at the left hand side by a hinge support and on the right by a roller support. It is under a non-uniform load intensity throughout by a load intensity given by: w = 25Cos(pi x/8)kN/m. Write equations for the shear force and the bending...
  49. S

    Temporal overlap of light beams

    Let's assume I can generate two individual light beams, one centered at a wavelength of 800nm (visible) and the other at 3450 nm (infrared). Obviously the visible light has a higher frequency than the infrared light. Since all EM waves travel at the speed of light, how can one achieve...
  50. R

    Castigliano's Theorem on Curved Beams

    Homework Statement You have a semi-circular cantilever with a point radial load at its free end. i.e load acting down from top of semi circle, with bottom attached to something. Calculate the equations for the horizontal and vertical deflections taking into account both bending moments...
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