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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Can someone explain to me von Mises equation for multi-axial (2D or 3D) stress
I am trying to understand what is in the wiki about the multi-axial (2D or 3D) stress
https://en.wikipedia.org/wiki/Von_Mises_yield_criterion
An equivalent tensile stress or equivalent von-Mises ...
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Hencky nets on the *interior* of a closed domain
The equations for Hencky nets are usually solved in the exterior of some domain; typical examples are the upper half plane or the exterior of a circle. I would like to know about examples of these ...
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Computing forces and moments acting on the sides of a rectangular shell element from corner forces and moments
I have a FEM program for shell elements implemented through the direct stiffness method. Using this program corner displacements of shell elements due to external loading are obtained through the ...
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3answers
60 views
Compute deformation response history from ground motion
I'm reading a book of Anil. K. CHOPRA related to Structural Dynamics, I'm intending to obtain the deformation response spectrum from given ground motion. What I have here in hand is ug(t) ground ...
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1answer
23 views
How can I compute minimum thickness for a rigid acrylic panel?
If I have an acrylic (plexiglass) panel, how can I compute how thick it must be to resist bending.
So, for example, if I have a sheet that is 24" x 36" and supported by the edges only (such ...
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Question regarding 2D simulation of orthogonal cutting operation on Abaqus
I'm trying to simulate an orthogonal cutting operation on Abaqus, I'm using Dynamic explicit analysis. I have defined my tool as Rigid analytical body and the workpiece is of Ti6Al4V, I have not ...
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2answers
84 views
Which yield strength should I use in FEA in ANSYS; Engineering or True?
Attached is a figure to illustrate the difference in the value of yield strength as observed from the true stress/strain curve and engineering stress/strain curve. While conducting FEA in ANSYS for a ...
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How to export 'simplified' geometry from Simulation workspace in Fusion 360 to ANSYS Mechanical?
I would like to export the defeatured version of my design to ANSYS.
I tried adopting the following methods but they weren't working out.
(https://forums.autodesk.com/t5/fusion-360-design-validate/...
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3answers
64 views
Boundary condition at supported end of a rod
I have one end of a rod held in a hole of a 'rigid' part with no clearance, while the other end is loaded with a force. I have shown 3 simple reaction-force models in the picture.
If my intent is to ...
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2answers
57 views
Calculating the von mises stress in a 3D beam when given stresses and moments on both ends
I want to calculate the von mises stress in a given structural member. I want to generate a von-mises plot from this data.
The forces are according to the local coordinate system of the beam. Also, I ...
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2answers
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Torsion of continuous vs simply supported beam [closed]
Say that I have a 2 span of continuous beam subjected to torsion, is the torsion value smaller than those 2 single span beam subjected to torsion of same value ??
I think the torsion of continuous ...
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1answer
61 views
Thrust force on wind turbine
Could someone explain me how thrust force produces a bending moment on top of the wind power plant's tower?
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3answers
183 views
Do all structures deform if put a load on them?
Suppose I have a concrete wall in front of me and I push on it, now it seems that I do work and the energy has magically disappeared.
I am trying to figure out how this works, the explanation I ...
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1answer
57 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 ...
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Constructing a structure with given constraints
I have a problem where I have a few points in 3D space with given constraints (forces, moments) and I have to create one connected structure which satisfies these constraints. Are there any pre-...
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6answers
573 views
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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1answer
107 views
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
60 views
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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1answer
20 views
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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52 views
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
98 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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2answers
60 views
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
32 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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0answers
25 views
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
76 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
86 views
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 ...
3
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0answers
25 views
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:
...
2
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3answers
83 views
Confused about internal hinges for calcualting reactions
[]
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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0answers
12 views
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
54 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
77 views
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
71 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
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
137 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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36 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
68 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
55 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
94 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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0answers
42 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
69 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
43 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
58 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
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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'...
