Here density should be 7800e-12 for steel material according to mm, ton, sec unit system. I made little mistake - instead of 7800e-12 I put 7800e-9. But static analysis are independent to density value, even you not need to define it. So analysis results remains same, Please don't bother about it.
Dear sir, I also confused about this point defining the mass density, I try to model the load for N, dimension for mm, Elastic modulus by MPa or N/mm2. in this case what mass density value I should use.
Dear, It is just unit conversion. If ur model unit is in meter..it easy to use MKS unit system. If ur model is in mm...it easy to use...mm,ton,sec unit. In case 2 (mm,ton,sec) Density become ton/mm3 Or 7800 Kg/m3 = 7800*e-12 ton/mm3 Similarly stress 1 N/m2 = 1*e6 N/mm2 or 1Mpa
dear sir, why should we define increments for linear, static analysis and small deformation? I know that for this case we solve the equation f=k*d one time that will give the deformation because stiffness matrix will not change, so why do we define increments and why does software solve the problem by dividing it into many increments (my qustion is only for static, linear and small deformation cases).
Dear, The general static step is based on increment method... whether stiffness changes or not (linear or nonlinear). This method converge solution in better way when convergence tolerance is higher than the specified tolerence. Let say for any increment ∆f = k ∆x convergence not occur due to larger difference un RHS and LHS (convergence tolerance). In next increment it consider lower step time and other subsequent values and try to converge. The method of direct solution (without iteration) is used in linear pertribution step in Abaqus. I also suggest you to learn FEA in this way... raise good question as you raised here. Read Abaqus documentation and practice finite element analysis book (Nitin gokhle sir).
Thank you for a great content. I have a question, though: in the linear simulation, I wonder how Abaqus is 'stretching' the length of the plate: is it stretching it via an additional tension force, or is it simply considering the plate as being longer and longer as time goes by, so no added stresses, just an additional length is given for it?
Dear, The reason you mentioned is wrong. As i told i video...in linear analysis stiffness matrix not change...so for large deformation also it not update stiffness matrix (it should be updated as shape of elements change)...hence nodes are not follow load path..
Dear Sir, Actually, I use Marc for structure analysis. have you ever use Marc Mentat. I wonder that I set the material yield criteria as Von Mises criteria, it means it will stop when I reach the criteria or not?.
Here density should be 7800e-12 for steel material according to mm, ton, sec unit system. I made little mistake - instead of 7800e-12 I put 7800e-9.
But static analysis are independent to density value, even you not need to define it. So analysis results remains same, Please don't bother about it.
Dear sir, I also confused about this point defining the mass density, I try to model the load for N, dimension for mm, Elastic modulus by MPa or N/mm2. in this case what mass density value I should use.
Dear,
It is just unit conversion.
If ur model unit is in meter..it easy to use MKS unit system.
If ur model is in mm...it easy to use...mm,ton,sec unit.
In case 2 (mm,ton,sec)
Density become ton/mm3
Or
7800 Kg/m3 = 7800*e-12 ton/mm3
Similarly stress
1 N/m2 = 1*e6 N/mm2 or 1Mpa
@@simtech0598 I really appreciate your response. It very useful information. Thank you.
Best video, I don't know how you manage you keep our intrest in the entire video. well done sir.
Just sharing knowledge dear.
Thanks for appreciation.
I'm just getting familiar with the software, and I must say your videos are quite elucidating. Thumbs up!
dear sir, why should we define increments for linear, static analysis and small deformation? I know that for this case we solve the equation f=k*d one time that will give the deformation because stiffness matrix will not change, so why do we define increments and why does software solve the problem by dividing it into many increments (my qustion is only for static, linear and small deformation cases).
Dear,
The general static step is based on increment method... whether stiffness changes or not (linear or nonlinear). This method converge solution in better way when convergence tolerance is higher than the specified tolerence.
Let say for any increment ∆f = k ∆x convergence not occur due to larger difference un RHS and LHS (convergence tolerance). In next increment it consider lower step time and other subsequent values and try to converge.
The method of direct solution (without iteration) is used in linear pertribution step in Abaqus.
I also suggest you to learn FEA in this way... raise good question as you raised here.
Read Abaqus documentation and practice finite element analysis book (Nitin gokhle sir).
Thank you for a great content. I have a question, though: in the linear simulation, I wonder how Abaqus is 'stretching' the length of the plate: is it stretching it via an additional tension force, or is it simply considering the plate as being longer and longer as time goes by, so no added stresses, just an additional length is given for it?
Dear,
The reason you mentioned is wrong.
As i told i video...in linear analysis stiffness matrix not change...so for large deformation also it not update stiffness matrix (it should be updated as shape of elements change)...hence nodes are not follow load path..
What if I have to do it on solid elements, which element type must be selected?
Dear,
Element selection depends on analysis type.
I uploaded one video that may helpuf - ruclips.net/video/PhZhNAwUaxI/видео.html
Dear Sir, Actually, I use Marc for structure analysis. have you ever use Marc Mentat. I wonder that I set the material yield criteria as Von Mises criteria, it means it will stop when I reach the criteria or not?.
Dear,
I'm unaware to word "Marc mentat"
sir i wanted to know what is solution for the convergence error occurred in material non linearity problem
Dear,
Whats problem you are facing... share visuals on my WhatsApp.