# Questions tagged [deflection]

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### Strength of Retangular Steel Tube

I have a retangular steel (A36) tube that is 2x6 inches with a 5/16 inch wall and 11 feet long. Can it center lift a 5000 pound weight attached evenly to its endpoints? How much deflection will ...
1 vote
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### Aluminum tube deflection

We're designing a new start bar for the Harris Hill Ski Jump in Brattleboro, VT. It's the bar the jumper slides out to sit on as he/she awaits the okay to go. Will the tube specs below be sufficient ...
62 views

### Calculating deflection of a cantilever beam using Young's modulus

I have looked at a lot of deflection questions on here and I didn't see anything that quite matched what I needed to know. I am working through some curriculum for students and I am working through ...
• 101
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### Calculate the deflection of a fixed supported beam

I am having a lot of trouble with the below question. Im not really sure how to calculate the deflection of the x coordinate, how do i go about completing this question? Any help would be appreciated ...
13 views

### Finding deflection on a uniform beam with fixed supports ~ Incorrect answer :(

This question has asked us to find the deflection of a beam (in millimeters) if the beam is under a load of: f(x) = 9.46(x+0.82)(9.2288-x) N/M The beam is supported with fixed supports at both ends ...
17 views

### Aluminium tube frame for retractable decking

Good Morning, I am designing a retractable floor in my deck to cover an in-ground hottub. So, the sections that are retractable will be 96" wide and about 48 - 57" long and on top will be ...
50 views

### Which beam deflects and twists more, open section or closed section?

Two beams, one open section (like an I-beam with flanges and web) and the other closed section (like a hollow square section) are cantilevered and have the same overall cross sectional moment of ...
• 1,365
19 views

### Multiple varying cross section beam with distributed load - FBD Method?

Based on the 2 different threads read below : Multiple Varying cross section beam deflection + Multiple varying cross section beam with uniform loads I'm trying to set up a calculation sheet (Excel is ...
75 views

### Need to find beam deflection of a steel tube

So I have a square tube of 40mm, 3mm wall thickness with a length of 1 meter. Both ends are fixed 25mm inwards. Load is 3kg centerpoint. Steel is SJ235. I need to know the deflection of this beam. ...
39 views

### Rigid frame deflection and material selection

I'm building a frame that will receive a point load mid span (likely it won't be but want to design for worse case). The frame is 1.5 x 0.095 square tubing, and it will be skinned with 14ga on one ...
47 views

### Maximum deflection of PSL + steel beam

I'm an amateur structural engineer, and I'm not understanding how to calculate multi-material beam deflection in my particular scenario. I start with a simply supported PSL (wood) beam that is ...
• 101
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### Which Deflection Formula is Correct for Hollow Aluminum Tube, Simply Supported, Uniformly Distributed Load?

Which deflection formula is correct for simply supported hollow aluminum tube with a uniformly distributed load (I've read conflicting answers online): δ = (5 x w x L^3) / (384 x E x I) δ = (5 x w x ...
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27 views

### Searching for geometric modeller to investigate behaviour of beam when deflected

I have the scenario where I wish to model the movement of a simply supported beam under a central point load. I've done some stuff in R Studio to come up with deflection plots and that's fine. In ...
279 views

### Find deflection and reaction force of a beam using Castigliano's energy method

I want to find the reaction force of support A and also find an equation for deflection using Castigliano's energy method for this beam. I know that the reaction force of A is 65.625 N but my solution ...
59 views

### In the context of Beam Deflections If the moment curve has a discontinuity, how do we account for it in the slope and deflection curve?

In reality if we load a beam within the elastic range of the material, it forms a curve that can be represented by a mathematical equation. But if the moment curve has a discontinuity it must mean ...
686 views

### Calculating deflections on an inclined beam

I'm applying a force to a stepped inclined beam (that's what I'm calling it; don't know what the correct technical term would be) in which it's essentially a cantilever with the first section angled ...
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### Cantilever Beam Deflection under Plane strain

I have a university code that calculates the maximum deflection of cantilever beam of length, $L$ subjected to a point load, $P$ on its free end. The software assumes plane strain conditions. I ...
25 views

### Do axial displacement experiments under hydrostatic load scale linearly to any size?

In J. D. Stachiw's book Acrylic plastic viewports for ocean engineering applications [PDF] on page 337 it includes a Figure 7.12 [2] showing the results of applying hydrostatic loads to an acrylic ...
210 views

I am trying to get the: maximum deflection location of maximum deflection deflection at any point For a beam under an arbitrary triangular load (i.e. a, b, c, and w can vary). I tried to solve this ...
1 vote
66 views

### Principle of virtual work "geometric proof"

I spent a full day searching for and trying to understand why in this "proof" of virtual work makes sense. I've come to understand the idea from D'Alambert's principle, but I want to ...
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4k views

### deflection of mild steel hollow tube beam

I am trying to compute the deflection of a hollow tube of mild steel, and my computation seems to give radically different results than a couple of online calculators. Apparently one is in error. The ...
230 views

### Composite Cantilever Beam Analysis

I'm trying to solve this composite cantilever beam for deflection analysis. How should I proceed? I'm not from mechanical background. The connection between the elements is strong enough that the ...
2k views

### What's the best shape (solid of revolution) for a cantilever beam to carry a point load at the free end?

How should you change the diameter/radius (while keeping constant overall volume) of the cross-section along the length of a round cantilever beam so that you minimise deflection with concentrated ...
520 views

### Deflection of Cantilever Beam with Midpoint Spring, Integration and Superposition Methods

How can I get the deflection required below using 1) the Integration and 2) Superposition methods (two ways)? The beam $AB$ is supported by a spring $CD$, which is fixed at $C$ with constant $k$, and ...
• 15
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### How is load bearing capacity of a leg of steel angle calculated?

Suppose a section of steel angle is used to support a structural beam, which would otherwise have no available bearing, as in the following sketch. Assuming that appropriate connection/fixing on the ...
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1 vote
580 views

### Castigliano's theorem for deflection

Consider a prismatic bar fixed at one end and acted upon by a force P at the other. According to Castigliano's theorem we can determine the deflection of point A by partially differentiating the total ...
1k views

### Calculate shear and deflection for simply supported beam on different support height (like a staircase)?

I’m trying to calculate the beam deflection for an inclined beam. It’s only connected to floors (and not walls). The beam is a monorail, and I want to test different shapes (tubes and I-beams). Plenty ...
• 101
111 views

### Ways to stiffen a HSS profile?

I have an issue with a post that’s deflecting a little bit too much. Picture a 10 foot HSS c-channel section, used vertically as a post. Web/flange 4.5 x 1.75 @ 3/16 thick. Clients (friends) insisted ...
1 vote
448 views

### Utilizing symmetry in statics problem

I am given the structure below, and supposed to find the forces occuring in $A, F, E, D, C$ and $B$. The task hints of using symmetry, as several forces are equal in magnitude. Supposedly, $A=B$, and ...
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5k views

### How much deflection can/should I accept with Aluminum Extrusions?

I plan building things with aluminum extrusions. On this website I can calculate the deflection depending on the profile length and load. https://8020.net/deflection-calculator I.e. if I select a 20/...
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### How to determine beam deflection with this unusual configuration (diagram attached)

So I've got a support system shown here in the attached image. Comparing configuration "A" to "B" it seems intuitive that "A" could support a larger load. The stubs are ...
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1 vote
169 views

### How does the stiffness of semicircular beams connected in series increases?

I am working to reduce the deflection in a cantilever/ dive board at work.$300 mm(L) \times 30mm(B) \times 2 mm(H)$, i.e. it's a rectangular cross section currently. I can't change the material, or ...
117 views

### Calculating the load on the end of a beam

We ordered a really nice light for our dinner table and ordered a special "lightswing" seperatly. The light that we ordered however is heavier than the 'lightswing' is rated for. Please see ...
653 views

### Deflection of a fixed-fixed pvc pipe under self weight

I would like to start by saying I am not an engineer, so I apologize if this question seems simpleminded. I am making a manual tarp reel from pvc pipe, and I am trying to decided whether to use ...
1 vote
2k views

### Multiple varying cross section beam with uniform loads

I have the following cantilever beam problem where I need to find the deflection of the tip at P. I tried to compute the deflection of the beam using Castignliano' s theorem as described in this ...
614 views

### Large deflection of a non prismatic cantilever beam under distributed load

Here's what I got trying to calculate the large deflection of a cantilever beam with two different cross sections under a uniformly distributed load: From the figure, the shear force is:  V(s) = q(...
788 views

### How can I find deflection in a member that doesn't have a constant area moment of inertia?

I'm trying to calculate the maximum deflection in a simply supported member with a uniformly distributed load. The trouble is this member does not have a constant area moment of inertia. I've drawn a ...
164 views

### simply supported beam with a midspan load

First off non-engineer apologies, A plate of 5251 Aluminium is used to support the load of a centrally seated human I estimate a load of 1 kilonewton. The beam measures a length of 1000mm, 100mm wide. ...
• 101
219 views

### Deflection of a cantilever beam composed of separate (not bonded) planks Uniform load

This is related to this question It is the case of a simple cantilever beam having a uniform rectangular cross-section. cantilever beam composed of separate planks - taken from The question in the ...
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### Deflection of a rectangular plate simply supported (transverse load)

I am looking for the formula allowing to calculate the deflection of a rectangular plate with a "transverse loading in its center" (maybe the kind of loading will be more clear with this picture : I ...
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1k views

### Sign convention for deflection and slope of beam?

What is the sign convention for deflection and slope of a beam as shown in the diagram below? When I derive the formula using Euler-Bernoulli for deflection and slope myself, I end up with - ...
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479 views

### Calculate deflection of a beam with an arbitrary shape

I have a beam with rectangular cross section, but rather an strange shape in the length wise direction as seen below: So I have taken out the symmetry part of it: And it actually has some nice ...
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730 views

### How to determine the deflection of a wire mesh under wind load?

I am trying to extend a metal wire mesh over a large distance, while tensioning it to limit the deflection of the mesh due to the wind as much as possible. After doing some research I came across ...
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482 views

### Flexure Deflection - Both ends fixed (one translation free)

I have a flexure problem. One of its ends is fixed to a frame (say F1) which is stationary (no rotation & no translation) and the other end is also fixed to another frame (say F2) which can move ...
179 views

### Deflection In Multistory Structure

When analysing and designing a structure for the serviceability limit state the deflections of each beam must be found. When considering a multistory rigid jointed structure (as below) and applying ...
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### What plastic material is best for a snap-fit design?

I'm designing a plastic holder that will secure a metal part with snaps. Which plastic will be able to take multiple removals and re-insertions without getting weaker (bent out of shape) over time? [...
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1 vote
135 views

### How to calculate load on roller to create given deflection?

I am trying to calculate what loading on a fixed roller will create a predetermined maximum deflection. I ran some calculations, but the values I'm getting are significantly lower than I would expect. ...
148 views

### How to size a rectangular steel tube to hold certain weight?

I would like to build a shelf (1m width and 0.5m depth) using only four rectangular steel tubes on for legs. Each legs are at the end of the rectangular tube. I would like to put 500kg on the tubes, ...
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### How to calculate the deflection of beam that is reinforced through formula?

Example an aluminium tube reinforced with steel tube inside. 100*50*2mm thick aluminium with 80*40*3mm MS tube
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