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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Why the design of continuous beam is always more economical than beam with supports?
Assuming that I have a beam that spans across a few supports. I can design the beam as a continuous beam (a beam that is loaded and has more than two supports), or individual beams that each encompass ...
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How to distinguish primary and secondary beam in FEM formulation?
Assume that I am writing a new FEM software for structural analysis, it shouldn't really matter whether this is a frame or frame+shell element analysis tool.
I understand that primary and secondary ...
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Can I reduce the column moment due to beam, by setting the beam end to pin?
I have a structure, which contains only frame elements ( beam and column).
From what I know, if I apply point load at the columns on both left and right hand side,and if the beam-column joint is ...
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Steel Roof Truss Shape Question
On a recent project for a outdoor shed the roof support structure did not look like one of the conventional roof truss designs I have encountered. See snapshot below. (The span is 10 m with the ...
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Properties of an hexagonal shape vs round tube shape
In a bike frame build, are there any differences between hexagonal cross-section tube instead of the typical round tubes?
Assuming that both are made from the same aluminium alloy and have the same ...
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General solution for the most critical pattern of live loading
From ASCE 7-05 code:
ASCE 7-05 Section 4.6 states "The full intensity of the appropriately
reduced live load applied only to a portion of a structure or member
shall be accounted for if it ...
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What is the general way for the slab loading be distributed to adjacent beam?
From what I know, for a nice rectangle slab with 4 edges bounded by beams, one can distribute the slab loading to adjacent beam via the Tributary Area method.
But what if the slab is irregular, or ...
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Vertical wave action on bridge
Rio de Janeiro, Brazil is currently stunned by the fact that yesterday a span of a brand new (innaugurated in January) bicycle bridge along the coast collapsed when struck by a wave, killing some ...
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Ansys Workbench - adding force in point
How to add force in certain point. I want to see influence of point force on my structure. (See image)
That force is for example weight of some tank or something similar inside my structure. I don't ...
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What is a Velocity, Pseudovelocity, Acceleration, Pseudoacceleration response spectrum?
I would like to know what is a velocity response spectrum, PseduoVelocity Response spectrum, and how they are different from one another? Could you also do the same for acceleration and ...
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What does it mean when actual member reaction is 100% of allowed?
I received construction documents for an extensive residential remodel and looking at the engineering there's a glulam drop beam with a calculated member reaction that is 100% of allowed (3965 lbs @ 5 ...
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Accidental Torsion and Equivalent Static Load for an irregular structure
Important note: I am writing a structural FEM software from scratch, so I won't able to use existing commercial FEM package. I would need to know how all the important quantities are calculated from ...
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How to transfer reaction forces of beam to a weld?
I have modeled a beam as fixed-fixed. The reaction forces are -1494 lb.ft and 761 lb (vertical). There is no horizontal reaction.
Now I know this beam is welded to another element. I am trying to ...
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How do I calculate the structural properties of a fiberglass laminated wood panel?
I'm constructing 2.2 meters span, 1 m wide shelf. Want to make it cheap but thin.
I'm planning to use 18mm thick OSB board and reinforce it with a layer of stronger material stuck to it's bottom.
My ...
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Determining the microstructure of steel after welding in modern computer software
How can the microstructure of steel after welding be determined in modern computer software?
I am aware that there are 'classic' methods of predicting microstructures like Schaeffler, DeLong or WRC ...
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How do you check a weld for applied moment?
I have a single angle connected to a double angle via a 3/16" weld
I know there is a factored, applied moment at that connection. I would like to ask how I can go about checking the capacity of this ...
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How Do You Determine Truss Stability in a Modeling Program?
This question originates from this and that question. I have realized the concerns boil down to the following figure.
Simply put, is the truss above, with the displayed boundary/internal fixity ...
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Truss manufacturer drawings unclear
I am currently looking at a set of truss layouts produced by our truss manufacturing partner for a residential building project. I have reason to believe these layouts are generated using Alpine (...
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How to calculate the relative contribution of each mode in seismic dynamic mode analysis?
In structural dynamic mode analysis, one would have to carry out modal analysis in order to get different modes that contribute to the response of the seismic ( or wind) force. Here is a nice summary. ...
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For a column, what does "rotation fixed and translation fixed" mean
So there's a permutation of rotation and translation each being either fixed or free for a column. What do each mean?
If the column is toe nailed to a plywood / beam underneath which is it?
If it's ...
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Is it possible to convert uniform loads to point loads?
I want to perform a structural analysis on a portal frame using a finite element solver to get a displacements and reactions for a load. The software library only accepts loads applied to node, not to ...
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How can we derived the equivalent Lumped Mass Model for irregular building and how to calculate the errors?
Intuitively, building can be represented as a lumped mass model ( the taller the merrier!):
Assuming a building is a lumped mass cantilever column also makes the global stability checks easier ...
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Is a particular bund/embankment geometry more stable than others?
I am interested in structural stability of earthen bunds. They are susceptible to being eroded by water. Let us assume I have a rice field that is surrounded on all four sides by earthen bunds. I ...
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How to derive Equivalent Static Load for irregular structure modeled with FEM?
Building codes such as the Uniform Building Code (UBC) or International Building Code (IBC) require the determination of Equivalent Static Lateral Forces in order to compute $P-\Delta$ effect and to ...
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Should P-Δ effect be considered for struts of a braced excavation?
Building codes such as BS5950 provide clear guidelines on how to consider P-Δ effect due to sway of a vertically loaded portal frame or single storey building, causing additional moment in the columns....
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Cantilever with three parallel rods
This is slightly similar to a question I previously asked but now I decided to simplify the question and model it similar to a design I have in mind.
I sketched out a slightly simplified model. It is ...
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How to find the angle of deformation in Ansys APDL?
After solving my problem in APDL, and started doing some post-processing, I want to find how much the deformed shape has rotated (i.e. the maximum angle the furthest node has made comparing with the ...
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Interpretation of shear flow/shear center of L-profile
I have calculated the shear flows and center of an L shaped profile. I assume they are correctly calculated (I followed the same steps as during the lectures for an I shaped profile). However, I have ...
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How should one model a structural model with both line elements and area elements?
I am modelling my structure using FEM, and my structure contains line elements (1D) such as beams and columns and area elements (2D) such as walls and columns.
My question is that, how can I proceed ...
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Best angle and length for a diagonal wood support for a pull-up bar
I want to construct a freestanding pull-up bar like the one described here.
But I was wondering what would be the best angle for a diagonal support considering that the things I care are:
That it ...
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From strain to displacement in 3d
I got a question thats been bugging me for a while:
Say that you're given a straight square beam (say one meter long), and you attach three strain gauges on each face. One at 0 degrees, one at 45 ...
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Arranging members within a truss efficiently
A wide variety of trusses exist for bridges and roofs. There are many different permutations when it comes to arranging the internal truss members. Depending on the direction, a diagonal member may be ...
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What could be the reason for these sections not agreeing?
I have two results that don't seem to match up and I can't figure out why.
I built a hollow square section (HSS) using two different structural analysis softwares (they both agreed). However, they ...
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Stiffness Method FEM - Slender Members
If a member is very slender then its length will be large compared to its cross-sectional area. I've heard and read that slender members can potentially cause the stiffness matrix of a beam/frame ...
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