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ROPS, rollover protection

ROPS, rollover protection

ROPS, rollover protection

(OP)
I have been asked to look at a ROPS design for a concrete delivery machine.  Does anyone know if (in the US) this can be done on a structural program like Multiframe or RISA, or does it require a nonlinear FEA analysis of some kind?

I think the relevant spec is SAE J1040.  Maybe CSA B352-M1980.  Are there others?

Thanks,
-Mike

RE: ROPS, rollover protection

I think you need to identify which spec you are working to. For SUV roof crush, for example, we'd have to use a non-linear code, because performance is defined in terms of intrusion.

Your other option is to design a structure that can be analysed by hand, which, combined with linear FEA for the rest of the structure, should allow you to predict its performance reasonably well. That's a higher risk approach, obviously.

Cheers

Greg Locock

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RE: ROPS, rollover protection

Seems like I've read that bulldozer roll cages are designed to absorb a specified amount of energy, rather than being just a stress-type analysis.  But should be covered in Code of Federal Regs, I would think, if you can ever find it.

RE: ROPS, rollover protection

(OP)
Thanks Greg and JStephen:

I am trying to get more info from the customer, also rummaging around the internet to see what I can find.  I currently have Multiframe and CADRE so I'm not sure I have what it takes to do this.  Things have probably changed a lot from when I did one of these in the late 80s.

Thanks again,
-Mike

RE: ROPS, rollover protection

Hi mrMikee,

FOPS and ROPS requirements are typically combined in the resultant cage design, depending on the industry.  For instance, for forestry mobile equipment, OSHA 1910.266, the FOPS requires a solid top and mesh sides.  A substantial FOPS can influence the structural design for ROPS and vice-versa.  Ref. SAE J1040, J231, J397.

From Greg's comments, it is interesting to note that use of non-linear codes have progressed into regulatory/safety evaluation requirements for automotive design.

RE: ROPS, rollover protection

Regarding JStephen's comments, I too have seen cages designed like this based on energy absorbtion via plastic deformation of the cage.

RE: ROPS, rollover protection

I think CSA Standard B352.0-95(R2004) covers the design and performance requirements for agricultural and construction equipment for ROPS

RE: ROPS, rollover protection

(OP)
I appreciate the comments.

I was hoping to have more info by now but haven't made any progress.  Just wanted to say thanks for the help.

Regards,
-Mike

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