Easy Strength/Structure Testing software for mac?!?!

[mrsollars]

--------------------------------------------------------------------------------

I'm looking at building some trailers and other structural pieces out of steel and aluminum. I am wondering if there is mac compatible software that would help with design, stress forces, etc.

I imagine plotting the design and then the program telling me that if i moved an axle 3.4inches forward, i could support much more weight, etc.

ANY design/strength testing stuff/information would be appreciated.

Thanks guys.

Matt

[William McCormick Jr]

I would check out some objects already built. Look at very old stuff and very new stuff. Look at the differences. Usually they use smaller stuff today. However sometimes you will see they actually used solid materials years ago where we use hollow stuff today.

Or they used schedule 120 pipe in older stuff, but use larger diameter schedule forty today.

Today you see trusses and trusses are ok as long as fire is not a concern. In a fire a truss will collapse very quickly.

You really should have practical experience working with steel or aluminum to know if something a computer tells you, is correct or not. Your inputs could be off. And their always the possibility the computer program could be flawed. Or inaccurate.

Just moving 40 foot "I" beams around while you are cutting and drilling them, makes you lose respect for their, solidness. You see them flex and bounce. You can physically bend them yourself with their own weight at those lengths. It is interesting to work with them. Highly educational.

There are underpaid black guys in an unheated steel shop that could teach the best architects about steel. Tell them exactly how much deflection they will get without a pencil.

People that are seeing an 'I" beam flex, for the first time, ask you if what they saw is true. That is how conditioned their minds are. They question the grade of material. They question the wide flange beam. They ask if it was made in China.

Moving 40 foot pieces of flat 3/8" or 1/2" plate around is a similar experience. It is not that heavy plate that will cut boot and break your foot or toe if you drop it. It is now a delicate flimsy Twinkie wrapper.

Sincerely,


William McCormick

[William McCormick Jr]

Remember aluminum in a fire has a very short life too.

Sincerely,


William McCormick

[mrsollars]

Thank for the input. I'm actually looking for specific software name/ title information. I will certainly check out the specs the computer gives me before doing any extensive work, but would need to the software to act as a guide in the first place.

thanks.
matt

[mrsollars]

bump.

[William McCormick Jr]

I don't think software is made to do that. Because the people that write the software have no actual guide to go by. All you have to do is look at the structural collapses in America.

When they design something today, it starts in a computer environment. The part moves to check clearances, I believe it can measure the stress. I could get the name to a simulator program. But the truth is you still have to know what you want to do, what materiels it will require. You pick materials by knowing the strength of them.
To be honest these simulator programs add cost, thousands of man hours. They add sales appeal and hype, but seemed to do little to actual design, calculation of loads, or finding reality. I would call them gimmicks.

Lets say for a metal arm of some sorts under power, you want this program to tell you what to make it out of. It cannot know. It might be better off out of box tubing if someone is going to touch it, or if it is exposed. It might be better out of an "I" or "H" beam if you have to through bolt a lot of equipment to it. Or run a trolley on it. Pipe might be the only choice, because a spring has to be mounted inside of it.

Depending on how you are mounting it, might make a big difference. If you are solidly mounting it, it might hold more as a boom. Then it would if it was suspended on two flexible points over twice the distance. Because you will not get the same flex, from the solidly mounted boom supported by a common or typical gusset. These are all things I know from actually fooling with it.

The problem is that most things today are done compact. So you need to know the minimum sized item you can get in there. How can the computer know how strong something is unless you give it a size. And a type of material. You have to draw in your structure or input the structure you think might be strong enough and then do your calculations.

I am sure it is much easier to just apprentice, if you can find anyone left that cares, to learn from. Today you will be lucky to get some "remember when they used to use" from two old timers talking.

But to be honest, you will have to do it a couple times wrong before you get it. Everyone I know that is worth ten cents has built some comical stuff over the years. We just laugh because we should have seen it. But it slips past you sometimes.

I do not know of any software that could calculate all the stuff an individual does while building something.

Sincerely,


William McCormick

[farmersamm]

Holy cannoli:gunsfirin

Go look at a pre engineered example of what you have in mind, then go home and build it:gunsfirin

[i4sillypwr]

There is software made to do that. Feel free to ignore McCormick. I'm sure they make it for macs but I doubt its as highly available as pc programs. My brother is a graphic designer and uses a mac and every single engineer I know uses pc. dunno why just they way it is I guess. It wont be cheap though lol. I dunno what a seat of solidworks runs. maybe 5k? Follow farmersams advice i guess or cough up the dough for a good program.

[mrsollars]

Thanks for the replies guys.

I'm assuming i have yet to be clear.

I'm wanting to design something on the computer......say......google sketchup style.

i'm looking for a program that will tell me where the highest stress points are in it.

We used to play a game with students in tech class called ''Bridge Builder'' (pc)

same basic principal. The kids build a bridge by dragging and dropping pieces of it together. press the ''stress test'' button. you add some reenforcement to these weak spots, then hit the 'test' button and a small train goes over the bridge.....if it makes it, you go on to the next level. (longer span, etc.)

i'm looking for something similar. i put it ''2'' mild steel box tubing'' then i piece it together to make a trailer frame. the i press ''show me the stress points under load'' button.
then the program makes suggestions on how to reenforce those areas to accommodate those stress points, etc. i make the changes.....abra cadabra.....i've got a solid trailer frame design that i just take the measurements from and build.

I know that i could just go to the trailer depot, take a few pics, and build it myself. i know that. i'm looking for something to experiment with. change up designs, etc, and still know that i can put some weight on the trailer.....exactly how much weight.....and still have the program tell me if it is or is not ''structurally sound''.

am i making any sense? it's late for me.

matt

[forhire]

I use Alibre design which is pc based. It has a design check module that can stress test designs. The link describes it: http://www.alibre.com/products/fea.asp

Are you looking for something similar?

I understand you want a mac based solution. Would you be willing to run pc software using bootcamp on your mac? Even high end solutions like solidworks lack native mac support.

[gordfraser]

If you can't get one for a mac and your 'Puter has an intel chip I'd recomend running windows on paralells.
I have it on mine and use it all the time. Works great.

G

[mrsollars]

parallels is no problem. just looking for the names of programs. sofar.....Alibre is all i've seen.

matt

[forhire]

What your looking for is Finite Element Analysis (FEA) software.

Alibre uses a version of Algor (I believe). SolidWorks and Autodesk Inventor have similar analysis capabilities.

You might check out CalculiX http://www.dhondt.de/ which is open source. You may be able to compile it or emulate it on your mac.

[mrsollars]

THAT is good info......

Thank you very much.

Matt

[forhire]

Take a look at the AutoDesk Algor site http://www.algor.com/ . It has a ton of information. You might do some reading to see if this is what your looking for. You can download a demo of Autodesk Algor for Windows which might get your feet wet.

This is AutoDesk's Mac compatibility page:
http://usa.autodesk.com/products/mac-compatible-products

I have a customer that uses Inventor and raves about it. I have no idea what kind of money he spent ;)

[farmersamm]

Bear in mind here, that I'm not trying to violate the terms of use on this forum. I'm merely trying to open up the conversation a bit. No personal attacks were contemplated.

I fully understand the sirens call to design on a puter screen. I understand it, but I don't like it. A good program, in the hands of a well trained engineer is a very powerful tool. But in the hands of a layman, or even a well versed journeyman, it can lead to disaster.

Lines on a screen don't replace good old fashioned observation of the world around you. Look at what others have done, and take the time to analyze the design. Not just look at it in passing, but really try to see where the makers provided for resisting different stress directions, and types.of stress. Sit there, and LOOK AT IT. Try to envision the lines of stress.............be the steel

Engineering is a cumulative set of observations, real world observations of catastrophic failures. And observations of successful structures too. The science is quantifying the results so that predictions can be made without putting people and property at risk.

That being said..........I'm a little disturbed at the current, and probably indefinite future, trend of statistical analysis. Engineering, from what I've gathered from smattered reading, has taken a new turn. Bell curves are being used in place of time honored safety factors. Or at least, modifying those factors. Economic pressure has placed restraints on the use of material and labor. Designs are becoming more "efficient". A 98% chance of failure is now the norm. I might be wrong, and dope slap me if I am. This is an overview of some stuff I read a while back. My degree was in Business Admin.:D

Another thing I don't like about the puter design thing is the fact that it's like a
Sears catalog. It's a wish list. Pretty picture, but not really connected to the workmanship required to transform it into reality. I can draw lines all day long, but unless I have the skill to construct the structure...........it's just lines.

Add to that..........total reliance on the puter generated design, while ignoring actual experience of people who have done the particular kind of work for a lifetime. Be it wrong, or right, people have a tendancy to bow the almighty electronic Gods while ignoring the advice of mere mortals. It's a stick your head in the sand kind of thing:rolleyes:

This is also a thing that sorta ticks me off about forums. Someone comes on, posts a question, ALL WITHOUT DOING EVEN THE MINIMAL AMOUNT OF RESEARCH ON THEIR OWN. I hate that. I'm not here to answer all your questions because I'm not qualified. I have enough of my own unanswered questions. BUY BOOKS AND READ THEM!!!!!!!!

The best questions are "educated questions". Something with a little inkling of knowledge behind it. Doesn't have to be correct, but at least it shows that someone has done some homework. A real discussion can develop from that kind of question.

Steel is a fascinating thing. The work that steel can perform is amazing. The time to learn, or attempt to learn, the limitations of steel is like gold.

I truly pray that we don't become a society that relies on others to do our thinking for us. By placing 100% reliance in a "program", we have given our decision making process to some unknown dude writing code. Did he transpose the stuff right, is there some faulty code in the program, is this even a valid premise.................

Go out and observe the world around you, see what works, and has withstood the test of time, try to understand why it withstood the test, and reproduce it

:waving:

[mrsollars]

thanks for the input. there were a bunch of suggestions in there. i'll try to consider them all.

thanks.
matt

[William McCormick Jr]

If you are going to be welding on a trailer you will see things on a really good trailer. That will not compute in your perfect software package. And they will not be on a cheap trailer. And the reason is that when you weld in braces, you create a new structure. You may take away flex that was being calculated on by the program when you designed the main support.

Now that you have welded in supports or structures, it is a whole new ball game. And the computer will not be able to calculate it. Not yet, anyway.That is why so many times they have after market fixes for engineered stuff. Because they did not know they moved the stress by welding or bolting on supports or structures.

I see failed air conditioning systems all the time. Noisy or they fall apart. Or they actually collapse, from slight vibrations from moving parts. All because someone used math to calculate what the forces were. Not what was actually being done, or actually what the part had to face.

I am saying by the time you know how to build something the computer will not be of much help.

Tri axil ocean racing boat trailers are made to be towed by a heavy truck. You can get away with a dual tire, pickup if it is heavy enough. But if the truck is a single rear tire vehicle, or too light. The truck sways. Back and forth back and forth. So that the pressure on the lugs and rim is so great so repetitive that the lugs loosen. And the tires pass you on the highway. A, 18 hour trip from New York to Florida for a race can cause failure.

If you look at the tongue weight you would assume you could tow it with a regular heavy duty pickup truck. But that is not the case by actual experience. The tracking forces of the tri axil trailer are to great, heat is caused in the rims and lugs, as the truck sways back and forth. And lugs loosen.

You have to stop every so often and tighten them up if you try this. Maybe cool them down.


Sincerely,


William McCormick

[worntorn]

Hi William

Could you please check your PMs and also a thread I have in "Shop, Trade and Sell"

I'm trying to get my old P+H set up for TIG welding and was told that you know a lot about these machines. Also I'm looking for a foot pedal + gas solenoid for this machine.
Sorry to hijack this thread, I've sent the PM a couple of weeks ago and posted the Shop trad and sell thread about the same time, so I thought it was time to hunt you down!

thanks

Glen Breaks

[i4sillypwr]

I think I would like to just follow McCormick around in real life and observe him and the people he interacts with and how they react to him. I dunno why but that just sounds ****ing interesting.

[William McCormick Jr]

Glen I only have a broken foot pedal. And the two I keep and use. One is a backup.

I fixed up and gave the other ones I had, to other guys on the forum. So all I have is a broken pedal for you.

I will look around for a gas solenoid but I don't know if I have anymore or where they are. Never had one go, but I did have some spares at one time.

Never got the private message.


Sincerely,


William McCormick

[William McCormick Jr]

I think I would like to just follow McCormick around in real life and observe him and the people he interacts with and how they react to him. I dunno why but that just sounds ****ing interesting.

You would love it. I do not hide my crazy ways. And to be honest most guys that work up on the 40th floor on a scaffolding, are pretty crazy themselves. They have great stories. They also have the details to what is actually causing accidents.

The electricians that risk their life every time they disconnect a neutral. Or pull a wire, or core a hole. They have great stories too. We get along famously actually.

We are loud and funny. You would not even find me unless you knew what I looked like.

The safety officers just put there heads down when they see me working. I am safe but funny. I tie noose knots for my safety harness sometimes.



Sincerely,


William McCormick

[worntorn]

thanks for the reply William. Is the foot pedal repairable?

Glen

[mrsollars]

keep this thread as long as you'd like gentlemen....just remember to say thank you.

matt

[William McCormick Jr]

If I am not mistaken the ceramic is cracked, the micro switch is gone, and the little bearing arm is frozen or broken. It is just a metal shell that you are welcome to. I will ship it.

Sorry about sending the topic off course.

Sincerely,


William McCormick

[worntorn]

will pm you

Glen

[Ed Danzer]

You are looking for FEA software. This is not as easy as creating a CAD model. I use SolidWorks for design and both CosmosWorks (now part of SolidWorks Professional) and Algor for FEA and Algor for CFD.

I was seat one of Cosmos in 1996, and adopted Algor (Autodesk) this year for linear and non linear FEA and for CFD to optimize fluid flow. The learning curve is steep and requires some training classes as a minimum. You should also qualify your design after construction. We sometime check the actual deflection to the calculated deflection to know if the assumptions for the design were correct. The first project we did in Cosmos was a done incorrectly and the product failed within the first few hours of use.

FEA software is not free and requires a fast machine with lots of RAM. I doubt your MAC is the best choice for running this type of software.

[macrylinda1]

parallels is no problem. just looking for the names of programs. sofar.....Alibre is all i've seen.

matt
What your looking for is Finite Element Analysis (FEA) software.

Alibre uses a version of Algor (I believe). SolidWorks and Autodesk Inventor have similar analysis capabilities.

You might check out CalculiX http://www.dhondt.de/ which is open source. You may be able to compile it or emulate it on your mac.

[tkanzler]

FEA software is not free and requires a fast machine with lots of RAM. I doubt your MAC is the best choice for running this type of software.My Autodesk Inventor Pro 2011 was around $10k, and Solidworks was slightly more. Plus a yearly subscription at $1k or more. And neither will design anything for you.