33 Replies Latest reply on Jan 14, 2019 4:03 PM by Frederick Law

# will solidworks simulation do a load analysis on a grate?

will solidworks simulation do a load analysis on a steel grate to where you can calculate how many pounds per square foot it will hold?

• ###### Re: will solidworks simulation do a load analysis on a grate?

It sure will.

• ###### Re: will solidworks simulation do a load analysis on a grate?

Yup

• ###### Re: will solidworks simulation do a load analysis on a grate?

Thank you for the reply. i need to find how many lbs. per square foot a grate will withstand to get a class rating. right now i'm being told to multiply the PSI x the FOS and then multiply that by 144in. Can you tell me if that is correct. Also i'm using Simulation Standard.

Thank You,

David Combest

• ###### Re: will solidworks simulation do a load analysis on a grate?

Do you have a model of this grate and the conditions (where to hold it and what load to apply) to put onto it?

• ###### Re: will solidworks simulation do a load analysis on a grate?

Hello Ryan,

Our company bought our software from GoEngineer. I do sheet metal drawings of stainless drains to send to the laser. No problem! Our company wanted software so we could calculate how many pounds a grate would withstand before failure so we could classify it as Class A,B,C etc. We were told that SolidWorks Simulation would do that for us so we bought one license and i got stuck with it. I've had very little training using the software. The information i did get said i could take the pressure load that was applied and multiply it by the FOS to get the psi. However, in using this formula with different grates i can plainly see that this doesn't look right. So now I'm having a hard time trying to get an answer that will tell me how to do what I'm trying to accomplish. I don't know if the software won't do what we want it to do or if I don't understand how to use the software. It's probably the latter. I would be ok with the problem being me if i knew there was a way to get the result i'm looking for.

I do appreciate your help and i do have lots of models with conditions, fixture settings, pressure, etc.

Thanks You,

David

• ###### Re: will solidworks simulation do a load analysis on a grate?

David,

I'm confident the software can gave you an answer.  Do you want to post one of your grates in this forum or would you like to email it in to me?

• ###### Re: will solidworks simulation do a load analysis on a grate?

Hello Ryan,

This is the first time I've used this forum. Hopefully I've attached the file correctly. Let me know if this is what you need.

I really appreciate your help.

Thank You

David Combest

P. S. Thanks to everyone for your help as well!

• ###### Re: will solidworks simulation do a load analysis on a grate?

David,

It looks like you have already received an abundance of advice on this.  A large amount of it seems to cover that you will need a better understanding of the boundaries you wish to use on your designs.  I'd recommend the use of boundaries that make physical sense to you.  The applied boundary of "23 PSI to the top of a cylinder that sits on your grate" may not be as intuitive as "36 lbs applied to the contact patch where a foot lands".  I generally recommend staying close to whatever real life loading this is supposed to be especially if you are new to Simulation.

The fixtures also play a large factor in how the results come out.  The "Fixed" fixture that you have applied now doesn't correspond well to any real life scenario and tends toward making the model seem overly stiff.  Using some softer fixtures that allow more degrees of freedom of the model to move tend to give more "true to life" results.  What you select for fixtures has a large impact on results.  These two sets of results differ by 15% in maximum stress just be modifying the fixtures (keeping the same faces) to more flexible restraints.  So, it becomes pretty important to make sure the fixtures being applied line up with the real life scenario.

Like Frederick Law mentions, without training on the tool and a background in engineering it will be tough to get reliable results that you can use to make load classifications.  GoEngineer can help with one of those though so do mind if I get a field tech in touch with you about going over some of this stuff in more detail?

• ###### Re: will solidworks simulation do a load analysis on a grate?

I have a guy from Go Engineer coming out Friday (Arvind Krishnan) from the Dallas Office. I have talked to him before but had a hard time trying to get a straight answer on how to find the result I'm looking for. No disrespect to Arvind, he seemed very knowledgeable but kept saying that they could not be liable. I understand that but still it doesn't help me a lot.

Right now I'm just trying to get as much information and understanding that I can so maybe i can ask him more intelligent questions. Wish me luck I'm sure I'll need it.

Thank You for all of your help!

Much Appreciated!

• ###### Re: will solidworks simulation do a load analysis on a grate?

David Combest wrote:

he seemed very knowledgeable but kept saying that they could not be liable. I understand that but still it doesn't help me a lot.

This is a safety concern.

If anyone tell you the grate is safe, they'll be liable when it fail.

Any PEng will avoid this thread.

We and GoEngineer could show you how to use SW but we can't tell you how to use the results.

• ###### Re: will solidworks simulation do a load analysis on a grate?

Understood. I don't want our company to be liable for misinformation either. That's why I'm here trying to understand what to do because i could see on my own that something was wrong with our current procedure. Normally i just do sheet metal drawings of drains to send to the laser. So the simulation stuff may be out of my league for now.

• ###### Re: will solidworks simulation do a load analysis on a grate?

I guess this is new requirement from customer?

So either your customer or your company need to subcontract an engineering company to certify the grate.

You can use SW to check your design before sending them to the engineer.

Before you change your design, find and contact the engineer.  They will have more knowledge on your local standard, engineering requirement and legal requirement.  All will define how your design should be.

The easier way is put everything back at your customer.

They tell you what they want and you just make them.  They are responsible for the design and requirements.

• ###### Re: will solidworks simulation do a load analysis on a grate?

Just to further complicate things: (I have not looked at the design ) I suspect since it is sheetmetal and having worked on other drains that due to the thinness if the material and the desire to know ultimate strengths the problem maybe of the geometrical non linear variety. Without complications beyond what would be practical the best you can do is a conservative estimate of ultimate strength otherwise you need to get into fracture and failure models which would not be worth effort. If this is in fact the case SWX Sim might do a reasonable estimate in the right hands but Sim Premium would be a better choice using an NL analysis with plasticity. You can't learn how to ski powder unless you get in it. Don't give up just get some help so you understand what realm your playing in and figure out how to get answers on the right side of wrong.

• ###### Re: will solidworks simulation do a load analysis on a grate?

David,

Arvind is a smart guy.  It is good that you are compiling a list of questions for him.

Is your background in engineering?  Are you the only one running that software in your company?  I ask these questions because teaching you the software is a comparatively small matter compared to teaching decision making, assumptions, and results analysis for engineering/FEA.  This is typically something you would get in a more involved formal training and not just a question/answer session.

• ###### Re: will solidworks simulation do a load analysis on a grate?

Ryan,

I'm not an Engineer. I have been doing sheet metal drawings for the past 5 years to send to the laser and break press and welders to put together our Trench Drains. The owner thought i was doing such a good job that he would give me the Simulation Software. I got some training but I'm not a mechanical engineer. On my own i have discovered that our current process is not the process i should be doing and I'm throwing up a red flag to our company.

Our company is small and I am the only one here that is trying to tackle this process. Now I'm very concerned on what needs to be done. I'm glad you know Arvind. I like him and everyone that i have had dealings with at Go Engineer so I've been very polite and respectful to everyone there.

• ###### Re: will solidworks simulation do a load analysis on a grate?

This is all good to know.  When you get a more complete list of questions you want answered you may want to post them up here and let us browse them and see if anyone suggests some additions.

• ###### Re: will solidworks simulation do a load analysis on a grate?

You'll need some training on how to use Simulation.

Your Solidworks reseller should be able to help.

Also it doesn't looks like you have much idea of loads, stress, tensile strength.

You'll need some engineering training for that.

There is a lot more involve then just buy a software and run simulation.

Simulation depends heavily on user input and setup.  So its easy to get wrong results due to mistake or misunderstanding.

• ###### Re: will solidworks simulation do a load analysis on a grate?

BTW who, beside you in the company did the load rating?

• ###### Re: will solidworks simulation do a load analysis on a grate?

Hello Frederick,

I posted the file and test i did on one of the grates to Ryan since i think he works for Go Engineer.

I understand where you're coming from. I'm probably in over my head but i do appreciate everyone's help.

Thank You,

David Combest

• ###### Re: will solidworks simulation do a load analysis on a grate?

We can help you with one grate but you'll need to learn how to do the rest.

Also a PEng is required to certify rating of the grate.

You and the company can say whatever the grate can hold.

Its the PEng's opinion that counts.

Talk to the person/company that will certify the grate.

• ###### Re: will solidworks simulation do a load analysis on a grate?

Frederick Law wrote:

We can help you with one grate but you'll need to learn how to do the rest.

Also a PEng is required to certify rating of the grate.

You and the company can say whatever the grate can hold.

Its the PEng's opinion that counts.

Talk to the person/company that will certify the grate.

If it is in the US you'll need a PE stamp not a PEng. Apples and Oranges.

And it depends on the application. If this is only within a machine and not near people then it is likely that no stamp is required. (IMHO)

• ###### Re: will solidworks simulation do a load analysis on a grate?

Yes, I'm assuming the worse.

Since it has a class rating, I'll assume its for foot or vehicle traffic and need some kind of certification.

• ###### Re: will solidworks simulation do a load analysis on a grate?

Yes it is for foot and vehicle traffic.

• ###### Re: will solidworks simulation do a load analysis on a grate?

Structural simulation covers a wide range of FEA problems—from the performance of a part under a constant load to the stress analysis of a moving assembly under dynamic loading, all of which can be determined using SOLIDWORKS Simulation Professional: Optimize designs based on structural, motion, or geometric criteria.

• ###### Re: will solidworks simulation do a load analysis on a grate?

Thank you for the reply. i need to find how many lbs. per square foot a grate will withstand to get a class rating. right now i'm being told to multiply the PSI x the FOS and then multiply that by 144in. Can you tell me if that is correct. Also i'm using Simulation Standard.

Thank You,

David Combest

• ###### Re: will solidworks simulation do a load analysis on a grate?

In a structure calculations without a deep understanding what you are doing and why you have a good chance to find yourself in trouble.

• ###### Re: will solidworks simulation do a load analysis on a grate?

PSI x 144 = PSF

It got nothing to do with what the grate can withstand.

PS

If you need someone to tell you how to convert PSI to PSF, let someone else do the simulation.

• ###### Re: will solidworks simulation do a load analysis on a grate?

Oh SNAP!

Feel that burn!

• ###### Re: will solidworks simulation do a load analysis on a grate?

Nothing burning.

Just observing from information given

Something could be burning on the grate.

• ###### Re: will solidworks simulation do a load analysis on a grate?

David Combest wrote:

will solidworks simulation do a load analysis on a steel grate to where you can calculate how many pounds per square foot it will hold?

How is the grate shaped? How is it supported? Can you share a picture?

I'd suggest you start with a simple hand calculation and work up from there.

• ###### Re: will solidworks simulation do a load analysis on a grate?

Your grate could take about 3psi with no FOS.

• ###### Re: will solidworks simulation do a load analysis on a grate?

Thank you Frederick!