Questions tagged [structural-analysis]
Structural analysis is the determination of the effects of loads on physical structures and their components. Structures subject to this type of analysis include all that must withstand loads, such as buildings, bridges, vehicles, furniture, soil strata, prostheses and biological tissue.
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questions
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Determining max shear stress
So I understand that shear stress can be either in the the form of transverse or torsional or both at the same time. And normal stress is due to the moment or a force normal to the surface. My ...
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Boundary Conditions of a Stepped Beam
I would like to ask about the boundary conditions to be considered in a stepped beam. For a cantilever beam wherein the one end is fixed while the other end is free to oscillate along the z-axis, we ...
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How to build instant mountain? [closed]
Create an instant mountain that is up to 2 km high, 5 km length, and 3 km width using expanding foam concrete.
Would it be possible?
Can we build houses on top?
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3answers
71 views
How to calculate beam impact problem
Can anyone help with this Impact problem? It does not seem very difficult but I am having trouble putting all the parts together.
Thanks,
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2answers
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How to simplify a truss bridge diagram?
Hello I have this truss structure question. I understand that we need to determine the zero-force members first so that we can simplify the diagram. But I am not sure which one that I need to ...
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0answers
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How quadrilateral elements represented in most FEA solvers for structural mechanics problems?
How quadrilateral elements represented in most FEA solvers for structural mechanics problems?
I know that Nastran-95 represent quadrilaterals for membrane and bending elements as a set of triangles:
...
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3answers
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Confused about internal hinges for calcualting reactions
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I'm really confused about internal moments.
Regarding image 1,
When taking moments about D (the hinge), why does the book only consider the right side? Could you technically consider the left side (...
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Anisotropic constants and progressive failure along-side ANSYS Mechanical model
I am modelling a CMC plate bolted to a superalloy plate in ANSYS Mechanical. I set up the orthropic material properties of the CMC from literature (x,y,z modulus and max stress), and I am using the ...
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2answers
51 views
How can moving boxes not require any tape and still hold 50 kg of content without the bottom breaking when lifting them?
The other day, I bought a bunch of normal-price moving boxes. They come as one big cardboard unit which you bend in various ways. When assembled, they appear to be extremely strong and yet they are ...
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3answers
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Shelf Reinforcements
Hi I know this is a little bit of a strange one, but I’ve got a relatively cheap shelving rack that I bought to make good use of garage space.
I have included a pic, It’s footprint is 1220mm x 610mm ...
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2answers
66 views
Pressure vessel wall dimensions
I am trying to design a small cooling setup which has two parts: the compressed air vessel and the turbines. My understanding is that the compressed air, upon being released, passes through the ...
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1answer
35 views
Economical difference with high-pressure vessel design pressures for fixed volume
Suppose space is not an issue and I need a fixed volume of compressed air (for storage), say 1m³. Is it more economical to manufacture a thick-walled vessel but with a smaller volume or a thin-walled ...
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1answer
59 views
Deflection Equation of a Stepped Beam
Help out a college student.
How do you derive the deflection equation y(x) of the shown stepped cantilever beam in the figure? Each segment has a unique Young's modulus and moment of inertia. The ...
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Using seismic base isolators in light, flexible buildings
Using seismic base isolators dissipate a great deal of energy that would enter to a structure, but at the same time they increase the natural period of vibration of the structure. Now, if we had a ...
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2answers
63 views
Given the same diameter and height, which is stronger? A vertical standing cylinder or a vertical standing rectangular?
I am interested in two cases. Case 1: Both are solid. Case 2: Both are hollow with the same wall thickness.
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4answers
63 views
Is it okay to replace pressure with point loads for structural analysis?
I am trying to analyse a wing structure in Ansys static structural. In most examples I have been through the lifting pressure is uniformly applied under the bottom of wing or it is simplified to point ...
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1answer
45 views
Boundary conditions for a cantilevered Timoshenko Beam
I am trying to find out the boundary conditions for above given Timoshenko beam. The boundary conditions that I have derived are
$x_1 = 0$
$$ \overline{u}_2^L = 0 $$
$$ \phi_3^L = 0 $$
$x_1 = \...
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3answers
66 views
How to derive fixed end moment of a beam fixed at both ends with a point force not in the center
So this is as far as I have gotten. The formulas written in green are the formulas that I have to find/ derive but I am hitting a wall. I know I am supposed to integrate but I am not sure where to go ...
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Craig Bampton Model Order Reduction on Ansys
I am in the process of modeling a component as a flexible body in Simscape Multibody environment (Simulink). I need to superimpose rigid body model with the deformation model.
The deformation model is ...
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2answers
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Best support for a granite table top?: Flat bar 316L Stainless Steel or equal box section or unequal box section
Project is outdoor granite topped table. Table legs are two isosceles trapezoids crossed together at 90 degrees, with the legs having an internal angle of 80 degrees, made from 100 x 100 x 4mm 316L ...
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1answer
37 views
Determine Stiffness (k) and Mass (m) of a system from impulse response
I have a test sample (Piezo Diaphragm) which I am actuating with a voltage supplied to the sample to assess the impulse response.
When this voltage is supplied to the sample a deformation per unit ...
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1answer
58 views
Correct axial force distribution between pinned ends of a member?
I have a planar member pinned at both ends with compressive axial loads at 1/3 and 2/3rd position of 14.4 applied between them. Is the following axial force distribution correct? Shouldn't the section ...
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1answer
54 views
compression buckling of frame
all. The top beam is subjected to uniformly distributed load. FYI, the column is 5m in length. As you can see, the major axis of column is connected to the beam with moment connection on top. However,...
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1answer
39 views
How strong is this spring compressor?
Disclaimer: amateur mechanic, not an engineer of any kind.
I just bought a spring compressor for my car. It's the factory recommended type so I'm assuming it's strong enough, but I'm wondering exactly ...
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3answers
73 views
Estimating dynamic load from human body
I want to build myself a pull-up bar. I am confident enough that I can guesstimate how much material I need for it to be strong enough, but this time I would like to challenge myself to properly ...
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2answers
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Can I convert multiple point loads into a single uniform distributed load?
I have a beam that has a given limit of 1690 lbs uniform load for a 24" span. I will be subjecting this beam to multiple point loads at different locations on the beam. In order to determine if ...
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3answers
36 views
Product picking carts
Does anyone know why product picking carts like this, commonly found in warehouses and supermarkets, are mostly just 3 or 4 shelves high?
Is it because of ergonomic issues or mechanical ones? Couldn'...
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1answer
61 views
deformable object squeezing
I have the problem following. There is a deformable sphere with radius r. It goes inside a constriction channel with d*d cross section. Assuming that the sphere volume is constant and the sphere shape ...
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1answer
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how can i find Spectral Acceleration (Sa(T1; 5%))?
I want to do incremental dynamic analysis (IDA) for my project and for hunt and fill algorithm i need the 5% damped Spectral Acceleration at the structure’s first-mode period (Sa(T1; 5%)) . Can i find ...
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0answers
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correcting mode shape for modal damping
I have mode shapes and eigen frequencies from FE simulation. I have modal matrix and eigen frequencies corresponding to each mode. The mode shape is mass normalized. I am required to correct each ...
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1answer
46 views
Question in finding the direction of forces in a truss
This question primarily involves finding the direction of forces in a truss.
Let's give a scenario in Method of Joints
One source I found says that in finding the direction of the source, it would be ...
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1answer
25 views
How to determine the fixed end moment?
I was trying to compute the fixed end moment for the beam (given below) using equilibrium equation for x, y displacement and moment but there are 4 unknown variables reaction and moment at both ends ...
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1answer
40 views
Reinforce foldable table legs
I'm trying to build a table with 4 swivel legs that can be locked into arbitrary angles so that it can stand over one to three rows of storage crates in my garage:
As you can see, the legs aren't ...
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34 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 ?
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2answers
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How effective are screen protectors?
Screen protectors are supposed to protect your devices from nicks and scratches, as well as the stress of impacts which might otherwise lead to cracks or shattering. The fundamental principle behind ...
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4answers
77 views
Bending moment calculation
Considering all the variables are the same, how to rank these connections from highest to lowest bending moment?
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1answer
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Where does the equation for shear stress of a rectangular beam (3/2 V/A) come from?
I am writing a report and need to reference every equation used. I am using the equation for shear stress in a rectangular beam of
tau = 3/2 * V/A
but am not sure where it came from or what textbook ...
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1answer
28 views
Elasticity values in stiffness matrix?
Stiffness, k, is defined by
$$k=\frac{Force}{deformation}$$
if you insert this into formula
$deformation = \frac{\text{Force}\times\text{ Length}}{AE}$
you get
$$k=\frac{A.E}{L}$$
where E is ...
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5answers
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Why are engine blocks so robust apart from containing high pressure?
Lately, I've been pondering why some engine blocks are so bulky, I always thought intuitively it was because they had to last a long time whilst containing thousands of combustion cycles but the more, ...
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1answer
48 views
Stress Concentration Factor – Why a Specific Range?
I was trying to find the stress concentration factor for a specific situation and I found two different resources for it.
Ref: Shigley's mechanical engineering design
Ref: Roark's Formulas for ...
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1answer
53 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 ...
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Help sizing of lug attachment flange/plate?
Apologies for the crude drawing attached, but here goes. Given Fx, Fy, and Fz loads applied at the lug hole, I've distributed the loading into each of the 6 fasteners to size them. I've also sized the ...
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1answer
48 views
Linear Motion Stage with Offset Loading Problem
I'm currently developing a linear motion system which will have to withstand a large offset load (see image below). There will be two rails, each with a carriage on, which will be connected by a beam/...
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0answers
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Finite element welding simulation with commercial software? [closed]
I am looking forward some libraries/add-ons to perform welding simulation (thermomechanical coupling, steel alloys) using commercial software, like Ansys or Abaqus. My aim is to determine better ...
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1answer
33 views
Mesh generation in FEM [duplicate]
When a frame structure is analyzed using a FEM computer software, does the program still generate mesh, even as a line mesh, on frame members, or we must do it ourselves?
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1answer
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Modeling the structure vs FEM
When you model the structure to be analyzed with a structural analysis program, indicating the beam elements, shell elements, nodes, rigid links etc... The analysis is still called Finite Element ...
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3answers
92 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 ...
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1answer
89 views
Bending of an L-shaped beam
First post so bear with me:
I am designing a frame for a press, which needs to be able to withstand 250 N. I am planning to make the frame an L-shaped beam, turned around. With a side view, it will ...
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1answer
116 views
Distribution of Forces into 3D Bolt Group
I'm trying to create an Excel spreadsheet that takes a 3D bolt group with x y and z coordinates, applied loading, and determines the distribution of forces into each bolt based on weighting by the ...
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1answer
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How to solve this displacement problem
I have to solve this question, and I've tried multiple things with the angle and displacement but I just cannot figure it out.
I started with a M/EI diagram and i went from there.
Any tips on how to ...
