Questions tagged [beam]

Questions about the theory and applications of structural elements designed to resist bending.

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2 answers
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Design of transverse reinforcement in a wide beam

Besides satisfying nominal bar provision in the code, is there any special requirement in the provision of transverse reinforcement to ensure that the longitudinal reinforcement is fully effective in ...
Rebar Lor's user avatar
6 votes
2 answers
356 views

How to analyze a bent beam: Stress concentration?

I am analyzing a beam, that has a bend in it. Intuitively and inspecting FEA results using a linear solver, there is a stress concentration at the bend of this I-beam. The part was not a straight I-...
user33108's user avatar
3 votes
1 answer
239 views

Design a beam that is straightened with force on one end

From here, I read that if you have a straight beam, bend it with force at one end, and then create a beam with the resulting curvature, the equal and opposite force won't make a straight beam. What ...
Eyal's user avatar
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2 votes
0 answers
35 views

Shape of a beam that is bowed under compression?

Suppose you have a uniform beam, such as a piece of plywood that is 4 feet long, six inches wide, and half an inch thick. Suppose you cause it to bend by attaching, for example, a string under ...
David Rose's user avatar
2 votes
0 answers
79 views

Thermal Expansion and Stress in a Heated Beam

Consider the case of a beam that is supported in such a way that expansion can occur freely. Suppose that the beam is heated in such a way that the temperature varies with the depth of the beam. Let $...
CrystalTerry's user avatar
2 votes
2 answers
210 views

How to design an enclosure around the load cell (Beam type)?

Hardware and Electronics Used: Arduino UNO, HX711 ADC Load cell amplifier, Load Cell (2Kg); Currently, I am working on a project which requires me to put load cell along with the other circuitry in an ...
Ganesh Hosur's user avatar
2 votes
0 answers
197 views

What is the optimal shape of a beam subject to three point bending?

Assume we have a beam with density $\rho$ that is subject to three-point bending according to the image above. The beam cross section is rectangular with the variable height $H(x)$ and constant width $...
RasmusN's user avatar
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2 votes
0 answers
89 views

Moment Of Inertia Specifications AISC

Is there some regulatory body/inspection that verifies the AISC specified Moment(s) of Inertia for steel I-Beams? So for example, if a mill produces a W8x21 and says hey, it meets the specs, it's 8 ...
Andyz Smith's user avatar
2 votes
1 answer
749 views

Problems with shear force diagram in beam model

I am starting to learn how to use ANSYS APDL. So I don't have much knowledge in the software. I have modelled a cantilever beam (with beam188 elements) and the only load that i have applied was the ...
Marina Vendl Craveiro's user avatar
1 vote
0 answers
46 views

How do I calculate kg/m for 5 boards sitting on 3 beams

I'm new to this, thank you for your patience, I have some wooden boards that each weigh 5.5 kg with dimensions of 120 cm * 60 cm I also have some wooden beams with dimensions of 3 meters length and 10 ...
user2263572's user avatar
1 vote
1 answer
90 views

Beam load - bending design value of southern GC yellow pine for treehouse beam span

I'm looking to build a treehouse and wanting to ensure the support beams can carry a sufficient load over an 11-ft span. Based on page 78 (aka 83) of https://awc.org/wp-content/uploads/2021/12/AWC-...
g491's user avatar
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1 vote
0 answers
81 views

On rectangular section beam properties of plate stiffeners

I am trying to understand the expression of the vertical dynamic stiffness $K_T$ and the rotational dynamic stiffness $K_r$ which appears in this paper where they consider a semi-infinite plate ...
Rann's user avatar
  • 11
1 vote
1 answer
221 views

Comparison of Shear Stress obtained from thin-walled beam theory and Timoshenko beam theory

I am studying the book "Structural Analysis with Applications to Aerospace Structures" by Craig. In Chapter 8 titled "Thin-Walled Beams", the authors derived the governing ...
Ali Baig's user avatar
1 vote
3 answers
136 views

How many support beams/rods needed for a firewood storage cabinet

I am building a firewood storage cabinet which should support around 100-150 kg of firewood. The cabinet is made out of wooden boards (...
ddofborg's user avatar
  • 111
1 vote
1 answer
157 views

Simple cantilever beam deflection - what is the simplest way to add a damper?

I am looking at a simple cantilever beam deflection: I understand the general expression for deflection/force would be: $$y_s = \frac{Fx_s^3}{3EI}$$ $$F_p = \frac{3y_sEI}{x_s^3}$$ If you were going ...
mike's user avatar
  • 161
1 vote
2 answers
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 ...
Kjell Stoelinga's user avatar
1 vote
0 answers
110 views

Pin connection on beam - FEA analysis

I am establishing a MatLab FEA code for determining the stiffness of a structure. Diagram of the structure is added below. I have established a code for determining the stiffness of the structure, but ...
Frederik Christensen's user avatar
1 vote
0 answers
63 views

Rotational bending in Timoshenko beam theory

The Wikipedia article on Timoshenko beam theory says: The model takes into account shear deformation and rotational bending effects, I am familiar with shear deformation, but what is meant by "...
S. Rotos's user avatar
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1 vote
0 answers
251 views

Simple beam deflection of cantilever beam

Recently I had need to prove the beam deflection equation for a simple cantilever beam with a point load at the end. The equation would be in reference to the Euler-Bernoulli theory taught in most ...
SteamTunnelBob's user avatar
1 vote
0 answers
1k views

Derivation of Bimetallic Strip Stress in Roark's Formulas

I am trying to understand some analytic expressions given in the handbook Roark's Formulas for Stress and Strain for bimetallic strip stresses. Namely, Roark's Formulas give the formulas $$\text{...
user19001's user avatar
1 vote
0 answers
420 views

How to add Beam cross section properties to imported mesh in Ansys?

Ansys Workbench 17.1 I have a mesh that was imported from Abaqus into Ansys but the beam cross section data is missing. As a result the structural model omits the beam elements. How do I access the ...
DrBwts's user avatar
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0 answers
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Equivalent spring of beam supported by springs

My professor gave us yesterday a problem to calculate the equivalent spring of the system shown in the attached figure. The problem: a cantilever beam supported by two springs $k_1$ and $k_2$ located ...
Thales's user avatar
  • 126
1 vote
0 answers
543 views

How can I use the bending stiffness of corrugated cardboard to determine maximum stacking heights of pallets loaded with glass bottles?

I am doing a project at the moment which involves improving the packaging operation at work. Right now I am looking at ways to improve packaging selection based on engineering principles, rather than ...
Phizzy's user avatar
  • 206
1 vote
1 answer
213 views

Beam stiffness matrix with sliding end release in arbitrary angle

I know how to get the stiffness matrix of a beam with any type of end releases (hinges and rollers) by applying Guyan reduction (static condensation) to the beam stiffness matrix in local axes. ...
cesss's user avatar
  • 121
1 vote
0 answers
230 views

Distribution of shear stress in beam bending

Beer, Johnston, and DeWolf's Mechanics of Materials includes the following image of the distribution of shear stresses in a bending beam: (Axes and load vector carried forward from Fig 6.1 in the text ...
ericksonla's user avatar
0 votes
0 answers
17 views

Why don't we calculate buckling in composite beams?

I have a frame, it consists of steel beams and my flooring is a composite deck. It consists of composite beams that are hinged to my steel frame beams. Composite beams do not transfer moments. Now, ...
Bilgehan Yılmaz's user avatar
0 votes
1 answer
29 views

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 ...
Lollipop 's user avatar
0 votes
0 answers
17 views

FInding deflection on a uniform beam with supports ~ Incorrect answer

Hello I am asked to find deflection of beam in millimetres at different points. The uniform beam is 3.55 meters long with a flexural rigidity of 32269Nm^2 It is under a uniform load of 92N/m and is ...
reira osaki's user avatar
0 votes
0 answers
9 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 ...
reira osaki's user avatar
0 votes
0 answers
33 views

How can I mount this plate on a Steel Beam?

As mentioned in the question, I am looking for a method to attach this mounting bracket to the flange of a steel beam that permits effortless removal and remounting without permanent fixation.
tesla's user avatar
  • 1
0 votes
0 answers
13 views

How to suppress longitudinal stress waves in a beam in FEA

When simulating a bending beam in FEA mimicking the textbook model and approach, unwanted stress waves appear. How to suppress longitudinal stress waves in a beam in FEA? To add friction/damping?
feynman's user avatar
  • 101
0 votes
0 answers
31 views

Is there explicit expersion for the natural frequency of a cantilever timoshenko beam?

I am trying to find a closed form solution for the natural frequency of cantilever Timoshenko beam. In mechanical vibration (Rao, 5th edition) he outlined the details to include the Effects of Rotary ...
AlFagera's user avatar
  • 113
0 votes
0 answers
13 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 ...
RGDOC's user avatar
  • 1
0 votes
0 answers
38 views

How much weight can aluminum square tube support?

I'm building a bed platform in a campervan and trying to determine what type of aluminum tube to buy. I'm thinking to purchase 6061-T6511 aluminum Square Tube with 1.5" width, 1.5" height ...
Cory Crowley's user avatar
0 votes
0 answers
20 views

Sign convention in link

If we take the moment about A from the $F_{BC}$ will make the body want to rotate counter clock wise but If we take it from the point C it will make the body rotate clock wise whats the mistake?
Youssef Mohamed's user avatar
0 votes
0 answers
34 views

Uniform Direction for Line Directions

Despite several similar questions and my efforts, there is still no solution so far. Presently, ANSYS gives Directions to Lines on its own which are flipped even for two collinear lines. As a results ...
Rehan Khan's user avatar
0 votes
1 answer
31 views

Need to Align Line Directions Normals Along Specific Coord in APDL

In Preprocessor of APDL, I have built areas which are meshed with shell element and lines meshed with beam elements. I have assigned Sections to Beam elements but when I view them their cross sections ...
Rehan Khan's user avatar
0 votes
0 answers
19 views

Mass Brick Settling Causing Excess Load On Center Beam

I live in a 115+ YO building and recently had my kitchen remodelled. During this the subfloor was replaced (old 1x6s in bad shape). I noticed a significant bow in the joists with the central steel ...
Michael33's user avatar
0 votes
2 answers
55 views

Is bending stress over round thin-walled tube cross section linear?

It is thin walled because roughly d=200mm and t=6mm of a carbon fiber wrapped tube. The question is, if the bending stress $\sigma$ over the cross-section (in y-direction) is linear or not. It is ...
Xenox's user avatar
  • 103
0 votes
1 answer
39 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. ...
Jooch's user avatar
  • 1
0 votes
0 answers
47 views

Setting direction vectors for Lines in ANSYS APDL

I am using beam elements to mesh lines with "pre-meshed" shell areas. Problem is that the ANSYS sets Line Direction vectors on its own. This results in Cross sections assignment flipped from ...
Rehan Khan's user avatar
0 votes
0 answers
60 views

Can someone help me with solving this beam problem using Rayleigh Ritz Method, my trial function is not working

The question is there is a two element beam joined together. The first element is 5m long and the other is 4m long. At the outer nodes there are roller supports and at the middle point where two ...
Aanamol Shrestha's user avatar
0 votes
2 answers
131 views

Shear Force in Inclined Beam

Suppose I have an inclined beam with a UDL applied vertically downwards, will the shear force act normal to the beam, or vertically?
Govnah's user avatar
  • 1
0 votes
0 answers
9 views

Justification for choice of beam stiffness at pinned far-end member

I’m reading off an example provided by the ICE structural analysis book, specifically example 4.7 (moment distribution method) I dont seem to understand why the stiffness from member D-C is 4EI/L ...
EduartR's user avatar
0 votes
1 answer
52 views

Beam deflection for FEA model validation

I'm trying to validate an FE model that I'm using by comparing to a simplified analytical solution to the problem. The part I'm analyzing is a lug that is constrained on one end and has a point load ...
Enzo 's user avatar
0 votes
1 answer
11 views

Mechanics of Materials Method for Curved Beam with Different Centers

The common curved beam theory covered is the Winkler method (e.g. in Johnston and Beer, or Boresi and Schmidt). As can be seen by reading any derivation, this method applies to beams with a common ...
Poisson Aerohead's user avatar
0 votes
1 answer
35 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 ...
TheKid760's user avatar
0 votes
0 answers
39 views

The Effect of Accelerometer Position on Modal Analysis of a Cantilever

We have obtained the first two vibration modal frequencies of a composite cantilever (33 gm). We placed the accelerometer (3.4 gm) near the fixed end and the two frequencies were F1=30 Hz and F2 = 256 ...
Rehan Khan's user avatar
0 votes
0 answers
21 views

Ratio of length to baseplate bolt pattern to assume that a joint is pinned

I have a truss tower that is attached to a hoist arm by a baseplate. The truss tower is 80ft long and the bolt pattern of the baseplate is a 1ftx1ft square. Is it valid to assume that the joint ...
Nachiket Adhvaryu's user avatar
0 votes
0 answers
31 views

Which formula to use to calculate the main vibratory frequencies of a wooden joist floor? (8 Hz?)

When a wooden floor joist is a little undersized, there is a vibration phenomenon when walking on the floor. In some forums, I've often seen a frequency of 8 Hz mentioned when walking on the floor, ...
Basj's user avatar
  • 101