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Questions related from Khaled Megahed
If 'P' is the part name The first form: P.ReferencePoint(point=(0, 0, 0)) R= P.referencePoints[l] P.DatumPointByOffset(point=R, vector=(10,0,0)) P.DatumPointByOffset(point=R,...
11 November 2019 4,501 1 View
I can use rigid body element or MPC constraint (type beam). What the difference between them? Is there any alternative way to define this rigid link? Thanks for reading
10 October 2019 5,663 3 View
Sometimes, for small angle the trigonometric, expression like sin(theta)/theta become produce ill-conditioned.
05 May 2019 5,186 2 View
The balance laws could be defined in term of Cauchy stress and 1st Piola-Kirchhoff stress tensor as follow https://en.wikipedia.org/wiki/Continuum_mechanics But could I define it in term of...
04 April 2019 6,409 7 View
Also when referring to variation in the work (virtual work), we use virtual rotation not rotation variation? Thanks.
04 April 2019 5,377 11 View
I would be grateful for any references or sites. Thanks
04 April 2019 8,816 1 View
Thanks
04 April 2019 4,221 1 View
Some researchers consider rotation variables as work-conjugate with moments, others think that the displacement derivatives is, and others use semi tangential rotation as work-conjugate to...
04 April 2019 5,448 4 View
Thanks.
04 April 2019 5,170 1 View
Most experimental results include true strain curve. How could I experimentally or theoretically reach effective stress strain curve or damage parameter for damage model? Thanks
03 March 2019 7,691 12 View
Using damage model includes the relation between the effective and true stress. The true stress-strain curve is the stress-strain curve measured directly from experimental tests which could...
03 March 2019 3,480 12 View
03 March 2019 6,919 1 View
Any papers, books,codes, or sites as a start? Thank you.
03 March 2019 7,793 3 View
Could wind tunnel provide accurate results to wind load distribution over the building? What if the building is very flexible like cable stayed bridges or tall building. Could it be simulated...
03 March 2019 6,334 13 View
People feel uncomfortable in the upper stairs of the tall building when the building move laterally due to wind load or to be accurate the lateral acceleration of the building. Is their any...
03 March 2019 5,157 10 View
In shell element I could define rebars layers to define reinforcement, but could I implement rebars in wire element? Thanks
03 March 2019 2,438 7 View
In 3D frame analysis, using elastic element with plastic hinge at nodes accelerate the solution time instead of using distributed plasticity. But most plastic hinges include interaction between...
03 March 2019 836 4 View
I encountered similar graphs like the one shown in the attached figure in many papers and researches. Does anyone use a certain software to draw this type of graphs?
02 February 2019 6,304 12 View
In modeling concrete fracture, I could use fixed or rotating smeared crack model. But when could I use each of them.
02 February 2019 4,196 9 View
STRESS(4) mean sigma(1,2) or sigma(2,3)? Thanks.
02 February 2019 921 1 View
When using Return Mapping algorithm, I implement Newton–Raphson iteration to reach the value of plastic multiplier. I know that the total value of plastic multiplier should not be negative. But,...
02 February 2019 8,464 5 View
I encountered a return-map technique in many papers but I do not understand how it works.
02 February 2019 6,113 3 View
I tried to code this method and it diverges when the stiffness approach zero. As, calculating load vector coefficient ∆λ requires having inverse of the stiffness as shown in the attached photo...
02 February 2019 5,291 4 View
I encountered using multi-directional cracks model in 2D elements, but could it be used for 3D concrete elements?
02 February 2019 261 15 View
Also how could I identify the pre-transition and post-transition parts of strain increment?
02 February 2019 5,105 6 View
These attached figures are captured from Concrete Frame Design Manual using ACI-318 attached with Etabs Design examples. It calculates the amplified moment due to second order effects using this...
02 February 2019 4,085 5 View
In radial RMA, the deviatoric parts of trail stress and iteration stress have the same direction, so the calculated shear stress after convergence is just a scale down to the trail shear stress...
01 January 1970 5,993 1 View
what is the difference between them? Which one could I use in beam element - shell -solid element? I read that beam uses first and shell uses second one, why? and what is the conjecture strain...
01 January 1970 9,209 12 View
Could the layout of the shear walls in multi story building induce torsional rotation due to dead load only? I faced this problem when analyzing a building in Etabs. Thanks
01 January 1970 4,348 10 View
Building exhibit torsional rotation under seismic loading due distance between the center of mass and center of rigidity. According to building codes, does this distance or torsional rotation have...
01 January 1970 6,439 8 View
I would like to know a finite element software which provides open source codes for large deformation analysis for beam and shell elements.
01 January 1970 5,589 18 View
Anyone has source code for beam element formulation with large deformation and large displacement. I tried to model it but the problem is in taking into account finite rotation. Most books written...
01 January 1970 2,580 3 View
How could I write the following formula in matrix notation? Any references, sites, or codes? Thanks
01 January 1970 6,618 3 View
In textbook I read this sentence "In the case of positive aerodynamic damping the forces generated by motion through the airstream tend to oppose the motion. Negative damping tends to reinforce...
01 January 1970 4,932 4 View
why lateral-force fluctuations frequency is half longitudinal-force fluctuations in turbulence flow or wind simulation?
01 January 1970 9,635 8 View
How could I use this tool to reach to wind pressure distribution over simulated building and How could I deal generally with the results? Thank you
01 January 1970 687 5 View
when using interpolation functions to get the interpolated values of displacement and rotation in Gauss point, we could define two separate equations; one for the displacement and one for the...
01 January 1970 8,391 3 View
I read about the membrane and shear locking appearing in shell element. Most references explain the reasons for shear locking but do not provide sufficient explanations for membrane locking. I...
01 January 1970 10,056 2 View
I am a beginner in understanding mixed FEM in structural analysis and I would be grateful for any advice, or reference that could help about this topic. Thanks for reading.
01 January 1970 9,353 2 View
What is the types of non conservative loads? distributed loads, concentrated loads, concentrated moments. what is the effect of non conservative load in solving finite element problems? Should...
01 January 1970 5,792 5 View
How the total potential energy is a unique function with respect to semi-tangential rotation? Also how the tangent stiffness matrix of space elements based on semi-tangential moment is symmetric?
01 January 1970 6,197 2 View
what is the difference between the C value in both equations in the attached photo?
01 January 1970 3,289 8 View
which is the best for modelling different continuum and structural elements; updated Lagrangian formulation or total Lagrangian formulation. Thanks
01 January 1970 8,992 8 View
What is the tensor type for Green Lagrange strain tensor and 2nd 2nd piola kirchhoff tensor? Stress and strain are called 2nd order tensor because they follow the transformation rule: sigma`= R *...
01 January 1970 7,790 5 View
If a system subjected to conservative forces and moments, at any circumstances the stiffness matrix could be unsymmetric
01 January 1970 5,926 5 View
what is the shell model with best performance for modeling shell element; using MITCn model or DKT or exact shell model proposed by JC Simo or ANDES elements? also the shape of it; quadratic or...
01 January 1970 3,544 2 View
I am looking for open source code for generating mesh for shell and solid elements. Any suggestions? Thanks.
01 January 1970 1,078 5 View
How could I convert this Tensor notation in the attached photo into Matrix notation? Any references, website or codes. Thanks
01 January 1970 9,861 2 View
There are several shell models that take into account drilling dof in shell formulation, and others not. What is the effect of using this dof in the accuracy and convergence rate of finite...
01 January 1970 454 3 View
When solving shear or membrane locking in shell element, most researchers assume shear and membrane fields or stress field for the element using mixed formulations. What is the methodology to...
01 January 1970 2,474 2 View
