Questions tagged [buckling]
The buckling tag has no usage guidance.
63
questions
0
votes
2
answers
45
views
Hollow circular columns vs solid circular columns of exactly the same mass and length, which resist buckling better?
I've seen a number of mentions in the tensegrity literature asserting (without proof or reference) that, in the context of a tensegrity rod under pure axial compression, hollow columns perform better ...
0
votes
1
answer
26
views
Is there a way to program a buckling analysis of an arbitrary shape, using a standard programming language/libraries (not Abaqus)?
I am trying to develop a program in Python that runs a few different basic analyses for optimization like minimizing compliance and buckling. I want to use machine learning to try to develop a fast (...
0
votes
2
answers
34
views
Can a buckling steel column fracture on multiple points?
When a column buckles, then yields, and finally fractures fractures, along the most stressed point, this will initially reduce the axial and bending strains along other points. The apparent conclusion ...
- 164
0
votes
1
answer
58
views
Determining the critical load of a fixed beam with non-uniform cross-section?
I am a computer scientist, not a mechanical engineer, so it is absolutely possible that I am missing some basic understanding here.
I have a beam that is fixed in both ends and my goal is to ...
- 101
0
votes
1
answer
41
views
How to calculate maximum buckling load for hydrofoil strut?
I am a hobbyist and in the process of designing a human-powered hydrofoil (see Hydroped for reference) I'm kind of stuck in the calculation of the the maximum buckling load for a strut.
The strut is ...
- 111
1
vote
5
answers
73
views
Describing 180 degree arcing/deflection of wire supported vertically at one end
I am trying to understand how to describe and calculate the shape a length of piano wire makes from its own weight when supported vertically at only one end. Is it a catenary or a parabola? ...
0
votes
1
answer
45
views
What is the critical buckling force needed to be applied on a system of made out of two parts?
What is the critical buckling force needed to be applied on a system of made out of two parts?
The parts of the system are as depicted in the picture:
incompressible elastic beam - on top
...
- 103
0
votes
2
answers
85
views
How to find the tension in wires before a column buckles
I already have the solution for this problem, I just need some explanation about a certain part. Can someone please explain the highlighted section, how do I obtain the tension formula used here?
- 286
0
votes
1
answer
93
views
Why isn't lateral torsional buckling of rectangular timber members dependent on torsional stiffness?
I'm reading about buckling of timber members from Eurocode 5: Design of timber structures part 1.
Section 6.3.3 gives instructions to check the stability of beams subject to compression, bending or ...
- 2,239
1
vote
1
answer
115
views
Stability of solid rectangular wood member
I'm reading about buckling of timber members from Eurocode 5: Design of timber structures part 1.
Formula 6.30 gives the relative slenderness of a member:
$$\lambda_{rel.m} = \sqrt{\frac{f_{m,k}}{\...
- 2,239
0
votes
1
answer
378
views
Stress concentrations around rivets in compression
The stress concetration factor for an unfilled hole is around 3, but it decreases when a rivet is present. What factor can we expect for a hole with a rivet in it in compression?
- 1
0
votes
2
answers
742
views
Calculation of critical column buckling load using Johnson's formula, but with eccentricity?
I've got partial answers but nothing comprehensive found online - most online resources focus on Euler's buckling formula which isn't appropriate for shorter columns.
Data I have collected:
Column is ...
- 571
4
votes
2
answers
262
views
Do yielded columns buckle?
A sufficiently slender column will fail under compression below yield stress by bowing, releasing it's axial elastic strain. This is called buckling. Depending on the slenderness of the column, the ...
- 164
1
vote
1
answer
295
views
Shear capacity according to eurocode , when to use which equation
I am looking at eurocode to calculate shear capacity, and under section "6.2.6 Shear", there are two different shear checks:
Eq 6.18
Eq 6.19
When there is no torsion we can use equation 6....
- 11
0
votes
0
answers
51
views
Why does figure 2 and 6 deform differently from the other shapes?
I am doing a linear buckling analysis on all the structures you see below, they are subjected to compression load in the x-axis as indicated by the arrow. You can see all structures beside 2 and 6 ...
0
votes
0
answers
32
views
How do I find the buckling strength?
I am running something called cell periodicity study in comsol, which finds the material properties of a model. It is done by applying a uniaxial compression load, and performing a nonlinear buckling ...
1
vote
0
answers
63
views
Do these linear vs nonlinear buckling plots make sense?
I am doing linear buckling analyses (where everything is linear), and nonlinear buckling analyses where you have nonlinear geometry enabled and nonlinear material behavior (hyperelastic material). ...
1
vote
0
answers
21
views
Why do we need to have perturbation in our system to do buckling analysis? [closed]
Do we need it for both linear and nonlinear system?
- 11
1
vote
0
answers
44
views
(Follow up) Can a thicker model giver a lower critical buckling load?
I present three seperate models with thickness of t = 0.005m, 0.01m and 0.025m respectively, all have a forced displacement of -0.01m in the x-direction, and fixed on the other end. As you can see the ...
1
vote
2
answers
108
views
Can a thicker model have a lower critical buckling load?
I perform a linear buckling analysis for two similar geometries, where one model has thickness t = 0.01 m, and the other has thickness t = 0.035 m. Otherwise everything is exactly the same. The ...
1
vote
0
answers
30
views
How is a linear buckling test supposed to look like?
If I had a cube like object; would this be a good way to set up a linear buckling analysis?
https://i.stack.imgur.com/Wqphm.jpg
And no other forces or boundary conditions
0
votes
0
answers
91
views
Solver cannot find any eigenvalues for linear buckling analysis [COMSOL]
I am trying to do a simple linear buckling analysis, where one end is fixed and the opposing end has a prescribed displacement of -0.1m in the x-direction that compresses the structure. Solver cant ...
1
vote
1
answer
143
views
What Causes Asymmetrical Buckling in this structure?
I've been playing around with structural modelling on the SkyCiv platform and have created this structure, related to a project I am working on to educate myself.
It is 2m wide, 3m long and 1.5m high ...
- 45
1
vote
3
answers
1k
views
Why does the upper wing skin fail in buckling and lower wing skin does not?
I am aware of the fact that the buckling is mainly caused in the regions of the specimen which are in compression. But the wing skin doesn't take any axial loads and is used to resist shear, atleast ...
- 1,337
1
vote
0
answers
87
views
How to calculate how much compression is needed for a spring to buckle
First off; School was many years ago and I know little of the mathematics behind all the physics and engineering stuff. So if you have an answer, please explain it like I'm 5?
The goal: I aim to be ...
- 111
1
vote
1
answer
68
views
Interaction of buckling modes
I'm reading this paper on structural members subject to both bending and compression.
In the first paragraph, in context of the equations 6.61 and 6.62, it is said:
The second two terms are modified ...
- 2,239
0
votes
3
answers
112
views
Meaning of this sentence in lecture notes about buckling of nonlinear column
Above picture is from my lecture notes. It deals with a column subject to axial load, which follows Euler buckling theory. The material is nonlinear, approximated by two lines as seen in the stress-...
- 2,239
0
votes
0
answers
37
views
Program name of this buckling modeling
My instructor sent this solving with program that I don’t know the name , does anyone know the name of the program ?
- 21
0
votes
2
answers
165
views
maximum allowed load [closed]
I have the following problem
E= 210 MPa
d = 40 mm
n = 20
y = 1.5
a =1
calculate the maximum allowed load for the system
I am confused on how to solve the problem, I really need advice.
- 103
1
vote
1
answer
633
views
unbraced length of the compression portion of a long member
I am designing a truss. the bottom chord in the first two panels at each end or at the supports are in compression and the rest of the bottom chord is in tension. there is no lateral bracing along the ...
- 11
0
votes
0
answers
345
views
ABAQUS: How to connect a shell edge with a shell face?
I'm performing a buckling analysis of a stiffened aluminium panel. The panel and flatbar stiffener(2) is created as one 3D shell extrusion. The T-stiffener (1) is another 3D shell extrusion.
How do I ...
- 1
1
vote
3
answers
510
views
Buckling of Parallel rods
I am trying to calculate critical force $P$, if two rods (same diameter and length - rigid fiberglass sandwiched on two steel plates) are parallel to each other.
$$
P = \frac{\pi^2 EI}{(KL)^2}
$$
I ...
- 25
2
votes
2
answers
285
views
How do I calculate how many newtons a hollow rod can carry without buckling?
how can I calculate how many newtons a 600[mm] long rod with a known yield strength (300 [MPa]), young modulus (190 [GPa]) and hollow (outer diameter = 16[mm], inner diameter = 10[mm]) will carry ...
- 23
4
votes
2
answers
353
views
Beam buckling criterion?
If I have an I beam which I subject to some bending load, how can I calculate when the thinner middle part of the I beam will buckle? I though I could use Euler's critical load formula here, but it's ...
- 159
3
votes
0
answers
36
views
How do FE solvers solve the case of panel buckling under pure shear?
How do FE solvers solve the case of panel buckling under pure shear?
The main problem is that global matrix of initial stess is singular in that case. One method is to apply some forces that shear is ...
2
votes
2
answers
106
views
Using modes from linear buckling analysis as imperfections
I'm reading this article on buckling.
It first introduces us to linear buckling analysis, and then mentions that linear analysis can be unrealistic as it doesn't take imperfections into account. Then ...
- 2,239
4
votes
2
answers
260
views
Why is local yielding considered the limiting case in context of buckling in Eurocode?
In Eurocode, when use buckling curves to calculate the maximum load that a compressive member can be subjected to before it risks buckling. Buckling curves are based on the Perry-Robertson formula. I'...
- 2,239
2
votes
3
answers
626
views
Why is buckling said to be independent of material strength?
In many sources, such as here, it is said that buckling failure is independent of the material's strength.
But in many building codes, yield stress of the material is a factor that changes the ...
- 2,239
10
votes
8
answers
2k
views
Definition of buckling as a sudden deformation
On Wikipedia, buckling is defined as follows:
In engineering, buckling is the sudden change in shape of a structural component under load such as the bowing of a column under compression or the ...
- 2,239
2
votes
0
answers
49
views
Can the critical buckling load from non-linear FE calculation be higher than the one from linear?
Let's consider a FE buckling calculation without plasticity.
Is there theoretically any chance that the non-linear analysis will give a higher buckling load than the linear one?
- 53
2
votes
1
answer
303
views
Twist "buckling" critical load
I have a very long beam which is subjected to a torque (I have the moments and shear forces with respect to X along the beam). I can calculate the critical load when the beam would bend if it was ...
- 159
1
vote
1
answer
309
views
For arc-length method in nastran, how to analyse post-buckling behaviour with load decrease
I am currently trying to model the buckling behaviour of a cylinder using sol 400 nonlinear static analysis using Nastran. I am using the arc-length (modified Riks) method as apparently it can ...
- 67
1
vote
1
answer
65
views
How would I do a buckling analysis with an additional fixed known lateral force?
I am using Nastran for buckling analysis, and I'm new to all of this so please bear with me.
For a linear buckling analysis, I understand that you must first apply any compressive load in the static ...
- 67
0
votes
1
answer
124
views
Why is buckling caused by nonlinear geometry?
I've been reading the Comsol post on geometric nonlinearity. The article introduces situations where the small angle approximation and linear analysis of structures gives inaccurate results. For ...
- 2,239
2
votes
2
answers
100
views
What is meant by "perfect geometry" in the context of Euler buckling?
In this question for example (in the first answer) it is said that the Euler critical load formula is unrealistic, because it assumes perfect geometry and perfect alignment of the load. I've found ...
- 2,239
2
votes
3
answers
2k
views
Buckling vs. Yielding Failure of Columns
As I have been working through examples of construction projects, I've noticed that in nearly every case of a structural column (sample size considers only homogeneous material columns, no composite ...
3
votes
0
answers
578
views
Column Buckling Boundary Conditions -- Welded Tubing Practical Application?
I'm trying to do some calculations for a personal project. I'm trying to understand column strength / buckling. My questions relate to Effective Length Constant, which is based on Boundary ...
- 281
1
vote
1
answer
231
views
Simple steel column buckling calc - where am I going wrong? (Eurocode)
I'm trying to follow an example of this, but I get a wildly different answer than expected and I can't see where I'm going wrong.
The example I've got, is for a 2.8 m steel column (RHS 150 x 100 x ...
- 571
0
votes
1
answer
452
views
MSC Nastran - BAR3/4 elements - can't assign any properties
I'm modeling a pipe in Patran, and I'd like to try bar3 and bar4 elements.
I assing the properties CBEAM to my geometry, but when I create the mesh, Patran tell me bar3 and bar4 don't support that ...
- 111
0
votes
0
answers
85
views
MSC Nastran CQUAD8 on a pipe - excessive pivot ratio
I'm modelling a pipe in Patran with CQUAD8 elements, but I get this error, like the structure is not costrained. I do have costrains on both ends of the pipe. What can the problem be?
If I use ...
- 111