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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How to design a structure to support W weight
I need make a structure to support nearly 2.5 tons of water (to get pressure for irrigation), not much height (2m. max) with a base of square meter aprox (~1m x ~1.2m).
I suppose the way to go is a ...
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6answers
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Increasing torsional-stress resistance of an Auger at its motor-shaft joint
An auger is used to move plastic balls and is rotated by a stepper motor. Due to the balls getting jammed sometimes, this induces stress on the auger at the motor-shaft junction and breaks. Images ...
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PE exam: situations in which two question choices are close to my final answer: how to pick one?
Consider this question:
I solve this eventual question and my answer is 7.29667:
Among the question choices are 7 x 7 ft and <...
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2answers
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Computing the stress field of a structure made of 4-nodes shell elements (accounting for membrane action, bending and shear)
I am trying to implement my own FE code for shell structures. Most literature provide formulations and strategies on how to compute shell element stiffness matrix. I can already compute deformations ...
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2answers
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How do I start determining the forces in the 3 bars?
For part A I have $\Delta$A + $\Delta$B = $\delta$. For part B I've tried summing forces at the joints but keep getting lost. Any help is appreciated my final is on Friday.
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Frame element stiffness with non-axis-aligned anisotropic area moment of inertia?
I've found equations for the $12\times12$ symmetric stiffness matrix for an element of a frame (a truss with welded joints): http://what-when-how.com/the-finite-element-method/fem-for-frames-finite-...
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Machine Analysis Problem: Finding the vertical force at joint K
Help me in determining the right solution in this problem. I already have an initial solution here but when I compute, my answer does not match to the answer key. I would like to know where did I ...
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2answers
62 views
Shear coefficient for an I-Beam
I’m trying to analyze the bending of an I beam using the Timoshenko beam equation and I can’t seem to find the value for the shear coefficient anywhere.
Surely someone must’ve done the work (given how ...
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How is any kind of structural reliability achieved if the probability of annual wind speed exceedance is 0.02?
Above is the definition of fundamental basic wind velocity from Eurocode 1. According to its instructions, wind loads on building are supposed to be calculated based on this velocity. It says that ...
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1answer
31 views
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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3answers
75 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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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
50 views
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
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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
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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
40 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
66 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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0answers
34 views
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
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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
66 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
48 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
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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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35 views
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
65 views
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
40 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
55 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
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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
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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
69 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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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
49 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
26 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
43 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
80 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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2answers
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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
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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
64 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 ...
