Beam Definition and 1000 Threads

Homework Statement Hi, I'm trying to figure out how to calculate the stresses in my beam. The cross section varies (shown in the picture), and I don't know how I'm supposed to think to find the maximum stress. I appreciate tips or links to learn how to do it. Thanks. Sorry if the picture is...

here "c" is the speed of light , i have a question in my mind and i have no answer for it , if two light beams are moving in opposite directions then their relative speed is simply c using the law of velocities addition in case of special relativity but what if those two light beams are moving...

According to the textbook, "In this case, you (A) and Jackie (B) no longer agree about her speed _relative_ to the speed of the light beam. She'll see the light beam pass by her at the speed of light, c, but you'll see it going only 0.1c faster than she is going." Illustration here, under "The...

Hi guys, how do I design the haunch for the cantilever beam? The slab area is relatively small, with 125thk ( 4.39m x 1190m ). I've looked through everywhere but I can't find on how to design the haunch. I'm using BS 8110. Thanks.

Hi guys; I have an analytical solution for the deformation of a beam due to a couple with moments C_1 and C_2 with boundary conditions y=0 and x=±(L/2) where L≡length of the beam. The derivation from the Bernoulli-Euler equation is below: \begin{align*}...

The question is: How do I find all the reactions? I haven't worked with a similar problem before, so I'm kinda confused. Hope someone will help! Thanks from now.

Homework Statement In this question , I don't understand why the KBC is 4EI / L ...Homework EquationsThe Attempt at a Solution I was told that for the far end pinned or roller supported , the K = 3EI / L , so shouldn't the KBC = 3EI / L.. Is the author wrong ? In the 3rd photo , we can see...

Hi guys, I have a set of 2-D data in excel, an X and Y column. The X column ranges from ±200 and the Y column is a Gaussian distribution ranging from about 6 to 12. In total there are about 500 data points. I need to normalize the data so that the Y column values have endpoints at 0 for X=±200...

Homework Statement I don't understand how the diagram of M/EI of conjugate beam drawn , can someone explain about it ? According to conjugate beam theorem , Homework EquationsThe Attempt at a Solution i know that the M/EI represent the w(x) , which is force per unit length of the beam . I...

I have a red 650nm and <5mW LASER pointer, but the beam is not very coherent. Actually, when I point to a wall at an approximately 300 meters away, the red point gets very large (about a meter in diameter). I wonder how a LASER could act like this?

Homework Statement http://cereference.com/book/structural-analysis/influence-lines-beams In the example , i don't understand the moment in the part of beyond AC . I don't understand why we don't have to consider the momenty due to unit virtual load in the part beyond AC , just like what we did...

Homework Statement why at C . the shear force V change from -0.5 to 0.5 ? We wantg to determine the shear force at different location , and a unit force is applied at arbitary location ( measured from A) ... Homework EquationsThe Attempt at a Solution IMO , there's no upwards force of 1...

Using : Ansys Workbench 16 Educational I want to build simple frame and simulate stress state and deformation when that frame is lifted. I have constructed my geometry in Design Modeler using line body's. My lifting cable has circular cross section with diameter of 10 mm. My frame has square...

Homework Statement For the circled part , i don't understand why it's 4 and 6 . I know that it's about distribute the moment according to the ratio that we have determined earlier . Homework EquationsThe Attempt at a Solution For 4 , shouldn't it be 240*0.4 = 96 ? For 6 , shouldn't it be...

Homework Statement In the first photo , i was told that the fixed end moment is zero when the far end is pinned or roller supported . Why in the example in the second and third photo( both end are fixed) , the angle is zero ? Homework EquationsThe Attempt at a Solution I think it's wrong ...

Homework Statement [/B] A thin, uniform, 3.8kg bar, 80cm long has two 2.5 kg balls glued on at either end. It is supported horizontally by a thin, horizontal, frictionless axle passing through its centers and perpendicular to the bar. Suddenly the right hand ball becomes detached and falls off...

Homework Statement why we need to consider 2 conditions , the beam curve downwards ( as in 11-3) and beam curve upwards ( as in 11-4) ? What's the difference between 2 cases ? I notice that in both cases , the author assume clockwise as positive here are the 3 consecutive pages of notes...

Homework Statement In the link at 12:35 , the author show the equation of the displacement of the beam without explaining , can someone try to explain why we need to use 3 Φ , 2EI / L , 2θa and 2θB ? I have no idea at all . Homework EquationsThe Attempt at a Solution

Homework Statement For the moment about B ' , why there is extra θA L behind ? 2. Homework Equations The Attempt at a Solution is that wrong ? I think there should be no θA L behind in the equation of moment about B '

Hello, My name is Molly. I am looking for help with Basic Engineering Calculations and how to understand them. This is not homework and certainly not for anything dangerous or anything I am building. I simply have developed a fascination for the subject and a strong desire to understand the...

Does anyone have an open source code or know how to code propagation of multi gaussian beams through multiple interfaces using the ABCD matrix approach? And this is using ultrasound and not optics. Please let me know if anyone can help out in this

Homework Statement We all know that $$\tau = VQ/ It $$ how to determine the shear stress at **G** ? I'm having problem of finding Ay centroid if the solid that i found earlier is y = 98.5mm There's a dashed line from G to the bottom . It's making me confused . for Q , should i consider the...

Homework Statement The laser beam is not a point source. It is known that it has a rectangular shape with a divergence of 30 mrad x 1 mrad. I would like to know how large my laser lobe will be at a distance of 250 mm from the laser source. Homework Equations I think you can use trigonometri...

I have an application where I am trying to figure out the shock load being applied to a metal pin (load cell). It is a cylindrical load cell which is supported at either end, and compressed in the middle. There is a slight gap between the end supports and the section compressed in the middle...

so I understand that it balances both sides of the scale but why does it have to be horizontal? in other balancing systems the beams do not have to be horizontal but in this system they do. I know it has to do with torque but can't seem to understand how the balance can be close to the right...

Hello, I have this model that required to be pressed vertically 1mm. I successfully displaced 1mm vertically with 30N of force. Unluckily, Von mises stress goes way beyond the yield strength. However, the strain is below the yield strain of 5%. I do not understand how ductile/flexible material...

I've often read that beam-powered propulsion is the only basic interstellar propulsion concept without physics problems. To me, that doesn't seem far from the truth. However, for a long time I've felt that the biggest obstacle to overcome is the beam divergence problem. Most of the concepts I've...

Hey guys, I've been reading my strength of materials textbook and its pretty much like a reviewer that contain several problems and short descriptions of their concepts. There's this formula that computes the maximum moment for two moving loads and its: [PL-(Psmall)(d)]^2/4PL where P= Psmall...

Homework Statement why the author said that by inspection , the maximum slope occur at D ? How do we know that ? He didnt show the working and explanation . Homework EquationsThe Attempt at a Solution If I consider the maximum slope to occur at a point after 2m from A , then i will take...

Take the case where the electron-beam is oscillating between two parallel metal plates, there will be alternating potential developed between the plates as metal tries to negate all external electric fields. My query is, (1) How to calculate the potential developed and possible way to simulate...

Hi So the problem I have is I want to get the equation of motion of a vibrating beam under a nonlinear "Point" force. The equation would be like this for a distributed load (Which is not the case) But I want the load to be at a point at x=L So I have to options. Add an impulse dirac function...

Homework Statement i'm not sure how to calculate the shear stress at point F and point G . I know that shear stress has formula of $$ \tau = VQ/It $$ The maximum shear force that i calculated earlier is V = 205kN , Ixx = 2.1x10^-4 for Q at $$\tau$$ at F , i have...

Homework Statement From the solution , it's clear that the top part of the beam undergo tension , while the lower part undergo compression . Homework EquationsThe Attempt at a Solution But , i don't understand why it is so . When the moment is applied in the horizontal axis , the structure...

Homework Statement i know this question can't be done(since the location of point where the tau 1 and tau2 are measured are unknown) , but i want just want to check whether my concept is correct or not . we know that the shear stress has formula of $$\tau = VQ / It$$ , the question want the...

Homework Statement Is it possible to find the VA , VB and VC without ' breaking ' the beam into 2 parts ? Homework EquationsThe Attempt at a Solution Here's my working , i gt Moment about A = 10(1) -VB(2) -VC(4) +5(3)(4 + (3/2) ) = 0 Hence , 92.5-2VB -4VC= 0 moment about B = VA(2) -10-VC(2)...

Homework Statement in the first photo , it's stated that the dy/dx at center = 0 , however , in the second photo (website) , it's stated that the dy/dx at the boundary = 0 ,which is correct ? I'm confused now http://www.geom.uiuc.edu/education/calc-init/static-beam/support.html Homework...

Homework Statement As in the diagram Homework EquationsThe Attempt at a Solution For part a ) , my ans is EI(d2y/dx2) = - Px For part b) , my ans is EI(dy/dx) = -P(x^2)/2 +c1 EIy = -P(x^3)/6 +c1x +c2 at x= 0 , y = 0 , so c2 = 0 , at x = 0 , dy/dx = 0 , so c1 = 0 , so , EIy = -P(x^3)/6 ...

Homework Statement for shear flow at D , the Q = Ay , i tried another method , i gt 30000 , instead of 29750, why the ans is different from 29750? why can't i use this method( i break the shaded area into 3 parts ( as shown in figure) Homework EquationsThe Attempt at a Solution Q = Ay =...

I have read that infinite time dilation goes hand in hand with infinite length contraction for photons. AKA "photons do not experience time", or from a photons perspective, it takes no time to arrive at its destination. What if you were floating in space with a laser pointer, and you pointed...

Hi, this is my first forum post - sorry if I'm in the wrong place, or I've done something wrong! Homework Statement Here goes: There is a beam of 0.5m length hinged to a wall at a right angle with 200N mass at the end of the beam. This is supported by a wire T at angle 30°. The question asks...

Homework Statement Assume a Gaussian laser beam ( 1064 nm wavelength) having an FWHM-diameter(intensity) of 5 mm. By transmission through a thin nonlinear crystal, a new wave is generated that is proportional to the square of the incoming field (and therefore radiates at twice the frequency, or...

Homework Statement In the example , I suspect the selected A (area) is wrong... From the notes , A' is the area of top (or bottom ) portion of the member cross sectional area . But , in the example , we could see that the selected area is located to the right of the point where shear stress is...

Hello PF, I am trying to analyze a a beam, connected to another beam at one side at multiple locations (bad quality drawing below). The top side of the beam extends further and sit on another beam, while the shorter lower side is directly connected to another beam. They are all bolted...

Homework Statement In this notes , why the shear force used is the 19.5kN ? Why not 6.5kN ? From what i know , the formula of shear stress is tau = VQ/ It , where V is the shear force ... There are two values of V in this question , why the larger one (19.5kN ) is chosen ?Homework EquationsThe...

Homework Statement I have an evenly distributed load with overhang and symmetry. I want to express the reaction loads as a function of support distances. I did the the 3 support problem with integrating a load structure and redundant and solving for the center reaction to find the outter...

A cantilever beam at low frequency behaves like an underdamped 1 DOF mass/spring/damper system. We are trying to find the roots of the Characteristic equation which are lambda1,2 = -dampingRatio x wnatural /sqrt(1-dampingRatio) Relevant formulas and given values: damping ratio = c/2sqrt(m/k)...

If I shine a laser beam through a calcite crystal, the beam is split in two, as shown below. Are the photons in the split beams in an entangled state?

Homework Statement Why we need to replace the 10kip load at 2ft from D to D ? Homework EquationsThe Attempt at a Solution IMO it's wrong ... There's no need to do that .

Consider the case in which an incoming particle collides with stationary target particle producing new particles through the interaction. For example, $$e^{-}+e^{+}\rightarrow X+\bar{X}$$ My question is, why in general do the particles produced in such an interaction propagate outwards are...

Can a beam of light be objectively in a specific photon number state (Fock state), let's say ##|2\rangle##? Or is it (the specification of the state) detector/observer dependent? I.e. we can only say that a beam of light is in a Fock state, but which exactly is detector dependent (detection time...