Most horizontal vessels I've lifted have lugs in plane with the slings and the rigging is designed to incorporate a spreader beam that allows the sling loads to equalise - ie. indeterminate as per GLND ROL and ISO 19902. Both examples you have at 17:51 conform to this concept, one spreader is longitudinal and the other has the(out of shot) spreader transverse to the vessel.
amazing prof. thank you. as civil engineer im impressed, we do alot of lifting process but we deal mainly with precast concrete structure . could you make example for simple precast concrete lifting, maybe some day thank you ?
It should match. But if not then kindly check your connections also check the reactions in all directions. Sometimes reactions does not match due to inclined loads in that case analytical force are calculated based on angles and compare with FEA.
That's really an informative video. Appreciated ...!!! I am having doubts, 1. Why we are not considering acceleration in the lifting direction? (4g, 5g) Because as far as I know, We do consider acceleration in case of problems like lifting analysis, transportation analysis. 2. If the lifting position is a little eccentric with CG of structure, then in order to avoid extra moments, what should be my boundary conditions?
Thank you for appreciation ! 1.This is just explanation video, how to perform lifting scenario, for lifting it should be 1g only. For transportation the acceleration will be higher. 2. The boundary condition represent the actual site condition, so you need to fix the geometry as per site condition only.. In order to avoid extra moment, you need to constraint the rotation dof.
Thanks for this amazing contribution. I applied same stage and that worked! But, How can i show the remote point lines (red lines) in results section for Rigid Body Dynamics?
Thank you! You can go solution information tree, on details view you can keep rigid, beam on on results, then you can able to view the rigids on results too.
hi guy, I follow you step by step and applied beam section result : yes . But, no red line from remote point to surface is create. i using ansys v17, plz help me way to show these red lines.
When you added the remote displacement, you set 0 to all six degrees of freedom, however the solved model you showed us only had X set to 0 in remote displacement. Could you please advise? When I only constrain X in remote displacement, I got a pivot message and the model cannot be solved.
Yes with only one dof fix, you can not solve the model. This is because, when you do lifting, some rotations will also happen. So in order to avoid pivot error you need to restrict the few rotation as well as translation dof. You can also fix all dof to get more conservative results.
Hi Bro. Thank you for your work. Could you tell me please. I ve made everything like you. But the slings are not shown. What should i do that the slings appear ?
I have done something similar with exact settings, but I get solver pivot error, I have done everything step by step as you have done, can you please advise?
Hello ! Kindly check the pivot point (node) location and make sure all the geometry components are connected with each other by checking connection. Once your all parts are connected, the error should not come.
Hello Sam, I had referred geometry file from free internet source. Please find video link for free cad platform: ruclips.net/video/JdJ2FTcvFKc/видео.html Also please find geometry modeling link for vertical pressure vessel. ruclips.net/video/WXKUCky9CtA/видео.html
Thank you! It will be same as lifting by hook, you can fix respective crane location. For inclination, you need to calculate force components and you can apply directly on lugs.
Grasp Engineering Thanks for reply! I have two queries 1. I need to analyse the tank at different angles. One hook is steady(on hold) and other is lifting the crane. So, I think my remote point(the one used at hold) will also move with different angles. Is there any way to do it in a single analysis instead of doing multiple analysis at different angles. 2. I am applying symmetry to reduce geometry to half and then I have applied remote displacement to only one hook. Will ansys apply remote displacement to second hook? (Due to symmetry)
You can either rotate geometry according to the rotation of your requirement or you can calculate analytical forces for rotation on lifting lugs and apply directly to horizontal tank. Don't go for symmetry until you will have node count issue. You can easily solve with full model.
In video you place remotepoint2 on co-ordinate system 2 but for remote displacement you select remotepoint predefined When i follow your method step by step and hit on solve then ansys shows error in defination Why
First you can create coordinate system then remote point and then you can apply the remote displacement. It is just to constrained so that lifting analysis will be done. Please brief further if you are not clear.
We explained how to perform the lifting analysis. We had considered empty tank. You can consider fluid weight by adjusting density in material definition and perform the analysis.
I had taken some readily lifting lugs geometry available. In actual their are few guidelines are given to design lifting lugs based on different load configuration.
sir i need your help My ansys is stuck at preparing mathematical model after completing 10 or 40 % kindly help i am following all your procedures but still stuck
Nice tutorial but it is not representative of what is really happening. Insert force reactions at the 4 lifting points and you will see the reaction forces are not correct! Rerun the study with the remote point behaviour set to Beam with the appropriate material and size. You will now see the reaction force going along the rope/sling line. This is still not 100% correct. Connection between lift plate and Beam is ridged, but in the real world the connection can rotate.
It is one of the method to perform the simulation (worst case scenario). You can use beam too, but rigid element do transfer all displacement and rotation from one to another location as it is. For FEA, you need to lock dof to perform the solution if you keep free it will show rigid body motion.
looking for this comment as i just recently discovered this issue. with the remote point i selected, i realized the forces in the Z direction are correct, but my force in the X and Y direction are independent of the height i choose for the remote point, and far less than they should be in actuality. I am unsure what the solution is for this, but i dont think remote points accurately resemble the lifting sadly.
This was super helpful and it still works on Ansys 2023. Thanks!
Glad it helped!
Most horizontal vessels I've lifted have lugs in plane with the slings and the rigging is designed to incorporate a spreader beam that allows the sling loads to equalise - ie. indeterminate as per GLND ROL and ISO 19902. Both examples you have at 17:51 conform to this concept, one spreader is longitudinal and the other has the(out of shot) spreader transverse to the vessel.
Thank you for comment.
amazing prof. thank you. as civil engineer im impressed, we do alot of lifting process but we deal mainly with precast concrete structure . could you make example for simple precast concrete lifting, maybe some day thank you ?
Thank you. We will upload if possible.
What stress intensification under the lifting shackles??
Thanks for wonderful tutorial. If the total force reaction is not equal to the total weight, what should i do?
It should match. But if not then kindly check your connections also check the reactions in all directions. Sometimes reactions does not match due to inclined loads in that case analytical force are calculated based on angles and compare with FEA.
Great tutorial
Thank you! Cheers!
Make a video for part-3 please, thankyou!!!
ok
Hello, Thanks for the wonderful tutorial. Where can I get the CAD Model
We generally refer grab-cad Library for CAD model or else we used to model in ANSYS.
That's really an informative video. Appreciated ...!!! I am having doubts, 1. Why we are not considering acceleration in the lifting direction? (4g, 5g) Because as far as I know, We do consider acceleration in case of problems like lifting analysis, transportation analysis. 2. If the lifting position is a little eccentric with CG of structure, then in order to avoid extra moments, what should be my boundary conditions?
Thank you for appreciation ! 1.This is just explanation video, how to perform lifting scenario, for lifting it should be 1g only. For transportation the acceleration will be higher. 2. The boundary condition represent the actual site condition, so you need to fix the geometry as per site condition only.. In order to avoid extra moment, you need to constraint the rotation dof.
Thanks for this amazing contribution. I applied same stage and that worked! But, How can i show the remote point lines (red lines) in results section for Rigid Body Dynamics?
Thank you!
You can go solution information tree, on details view you can keep rigid, beam on on results, then you can able to view the rigids on results too.
Hi !
I have made rigid beam on results is on, but there are no connection lines showed up in results section. Any suggestions?
You can go to solution information and in details you can select visible on results:yes
hi guy, I follow you step by step and applied beam section result : yes . But, no red line from remote point to surface is create. i using ansys v17, plz help me way to show these red lines.
When you added the remote displacement, you set 0 to all six degrees of freedom, however the solved model you showed us only had X set to 0 in remote displacement. Could you please advise? When I only constrain X in remote displacement, I got a pivot message and the model cannot be solved.
Yes with only one dof fix, you can not solve the model. This is because, when you do lifting, some rotations will also happen. So in order to avoid pivot error you need to restrict the few rotation as well as translation dof. You can also fix all dof to get more conservative results.
Hi, Is part 3, inclined lifting video available. Please provide.
you can do analytical too but we will upload, you can refer other lifting analysis like fork lift from our channel.
Hi Bro. Thank you for your work. Could you tell me please. I ve made everything like you. But the slings are not shown. What should i do that the slings appear ?
Please see all the video parts, it is shown in the video. You can see from results details by keeping beam on results option yes.
@@graspengineering9249 ok. Thank you. I will check. Could you advice me some books or sources to learn static mechanical calculation deeply?
I have done something similar with exact settings, but I get solver pivot error, I have done everything step by step as you have done, can you please advise?
Hello ! Kindly check the pivot point (node) location and make sure all the geometry components are connected with each other by checking connection. Once your all parts are connected, the error should not come.
could you please make video how did you make this body (tank or cylinder) ?
Hello Sam, I had referred geometry file from free internet source. Please find video link for free cad platform: ruclips.net/video/JdJ2FTcvFKc/видео.html Also please find geometry modeling link for vertical pressure vessel. ruclips.net/video/WXKUCky9CtA/видео.html
Great video, with complete details. I'm looking for lifting by two crane. Please upload video for that.
Thank you!
It will be same as lifting by hook, you can fix respective crane location. For inclination, you need to calculate force components and you can apply directly on lugs.
Grasp Engineering
Thanks for reply!
I have two queries
1. I need to analyse the tank at different angles. One hook is steady(on hold) and other is lifting the crane. So, I think my remote point(the one used at hold) will also move with different angles. Is there any way to do it in a single analysis instead of doing multiple analysis at different angles.
2. I am applying symmetry to reduce geometry to half and then I have applied remote displacement to only one hook. Will ansys apply remote displacement to second hook? (Due to symmetry)
You can either rotate geometry according to the rotation of your requirement or you can calculate analytical forces for rotation on lifting lugs and apply directly to horizontal tank.
Don't go for symmetry until you will have node count issue. You can easily solve with full model.
Remote point position will carry according to tank rotation.
Grasp Engineering
Okay will do that.
Thank you very much for help.
that sling is not showing for me what to do sir,
@graspengineering
Check analysis setting and On the Cerig options.
In video you place remotepoint2 on co-ordinate system 2
but for remote displacement you select remotepoint predefined
When i follow your method step by step and hit on solve then ansys shows error in defination
Why
First you can create coordinate system then remote point and then you can apply the remote displacement. It is just to constrained so that lifting analysis will be done. Please brief further if you are not clear.
Where is the weight of the tank you are lifting ?
We explained how to perform the lifting analysis. We had considered empty tank. You can consider fluid weight by adjusting density in material definition and perform the analysis.
Thanks for this valuable video! Did you built the model in modeller ?
Thank you!! Yes, It is easier to model in design modular...Refer vertical pressure vessel modelling video using design modular.
Sir, how did you model the section containing the lugs?
I had taken some readily lifting lugs geometry available. In actual their are few guidelines are given to design lifting lugs based on different load configuration.
Hello, where is part 3?
Will try to upload. Please check the lifting beam analysis video for more details on lifting scenarios.
Yes we need third part, kindly upload for our use, it is needed...
sir i need your help My ansys is stuck at preparing mathematical model after completing 10 or 40 % kindly help i am following all your procedures but still stuck
okay, let us know your issue ?
Ads voice are more clear than your videos.
Your videos are excellent but
Please do work on sound system.
It was old video, please check recent video now.
Nice tutorial but it is not representative of what is really happening. Insert force reactions at the 4 lifting points and you will see the reaction forces are not correct! Rerun the study with the remote point behaviour set to Beam with the appropriate material and size. You will now see the reaction force going along the rope/sling line. This is still not 100% correct. Connection between lift plate and Beam is ridged, but in the real world the connection can rotate.
It is one of the method to perform the simulation (worst case scenario). You can use beam too, but rigid element do transfer all displacement and rotation from one to another location as it is. For FEA, you need to lock dof to perform the solution if you keep free it will show rigid body motion.
looking for this comment as i just recently discovered this issue. with the remote point i selected, i realized the forces in the Z direction are correct, but my force in the X and Y direction are independent of the height i choose for the remote point, and far less than they should be in actuality. I am unsure what the solution is for this, but i dont think remote points accurately resemble the lifting sadly.
Very informative but you are too fast in your explanations.