SimScale CAE Forum

Hoist ring and bolts stress analysis


#1

Hi,

I have the current project which is part of a critical operation the steps as follow,

1- An overhead crane will lift an Injection Mold (The device that can make plastic parts ). Its weight is 38000 Ibf.

2- The connection part is what we need to analysis the stress on it .in other words, to see what is the typical screws size that can assist in the lifting process.

3- The connection parts are consist of Swivel Hoist Ring, thick plate and bolts. The bolts are tightened to the injection mold (tighten torque value of the bolts is neglected ). I have attached the mechanical properties for the bolts. In case we need to use the torque.

4- The thick plate is positioned in the middle of the injection mold. No pattern for the bolts, some times is a different pattern.

5- because of the crane is an overhead crane, so there is no angle in the chain of the crane that connected to the Swivel Hoist Ring. The crane will lift the injection mold vertically and place the injection mold on the track vertically too.

https://www.simscale.com/projects/rkena/hoist_ring_and_bolts_stress_analysis/

Tips

*Seating torques for alloy steel calculated in accordance with VDI 2230, “Systematic Calculation of High Duty Bolted Joints,” to induce approximately 120,000 PSI in the screw threads through 0.500-inch diameter, and 115,000 PSI over 0.500-inch diameter.


#2

Hi @rkena and thanks for reaching out to us!

Can you please add a more detailed description of your problem as well as the project link? That would help a lot!

Best,

Jousef


#3

@jousefm seems like this is the project: https://www.simscale.com/workbench/?pid=5956159141523355102 (same text in the description) .

Looks like a very interesting project and should definitely be doable!

Best of luck! Let me know if there are any issues I can assist you with.

Richard


#6

Hi all ,

I will need your help to define my variable . I deleted the project and re upload the same one. The previous simulation gave me an error during the iteration time. I consider Design of Bolted Joints in Tension under dynamic
load loads. because the overhead crane will lift the injection mold vertically . please let me know if you consider the starting point for the dynamic load.

Rae


#7

Hi @rkena,
before we are able to help you we would need a better CAD model. Yours has all the parts merged together. With this model, even if it would mesh, we won’t get any relevant results.

Due to the merging of the parts, there are some artifacts being created, see for example this “ring” inside:

Also the imprinting just creates unnecessary problems and should be removed:

Once the CAD is cleaned and prepared properly we should be able to mesh it and set up the analysis.

Best,
Richard


#8

Hi Richard,

We made a small change into the geometry by eliminating the Swivel Hoist Ring from the geometry. This is the case that we need to evaluate the forces and the stresses on the bolts. The simulation ran successfully, But I am not sure the results are accurate.


#9

Hi @rkena,
with a first order mesh I wouldn’t expect the stress results to be accurate here.
Additionally the model has some significant simplifications compared to the real world case: no pre-stress (seating torque) is taken into account and your material is linear elastic.
If the pre-stress is taken into account and the material behavior modeled as plastic, we should get more realistic results.

Best,
Richard