Well, I broke it.

pugslyyy

Expedition Vehicle Engineer Guy
Well that would be the applied loading... What are these results we are seeing. They do not appear to be bending or shear stresses. Deflection?? Not questioning, just have questions.

deflection/bending - basically pushing up in the middle and down at the ends.

I've been doing some other ones to simulate cross-axle which make the results a bit more fun.

I don't have constraints set up for shearing to show in this model - difficult to generate because it is a metal fatigue issue anyway. But I can show where the stresses are concentrating. That's really what I look for - where are the stress risers and what can I do about them.

Since the frame is formed out of plate, you get nice radiuses everywhere which really helps.
 

mog

Kodiak Buckaroo
Not my quote or thought (see pugslyyy's post). I have not see Mitsubishi say the Fuso is not for off-road and I have see advertising from them, with the Fuso in an 'off-road' situations working as designed.
Mine has been and will be off road.


Next time you are in the dealership, take a look at the caution sticker on the interior of the driver's door!

I guess it must be a 'model year' thing then ?
No caution sticker on my FG (2002) and according to the Owner's Manual
-
fuso-offroad.jpg
It would appear that my Fuso is blessed by Mitsubishi with off-road operations.
-
Even Happy the Fuso does a lot of that in the Owner's Manual
(click to enlarge)
Happy the Fuso.jpg
-
-

Update:
Even the 2015 Fuso FG sales brochure shows "off-road"
(click to enlarge)

2015 fuso sales brochure.jpg
 
Last edited:

pugslyyy

Expedition Vehicle Engineer Guy
Okay, time to pull the thread back to it's original discussion point...

Here's my poor frame section (with the extension at the rear already removed) The pieces lying flat to the left were cut off, a result of removing/salvaging the frame extension.
10558897_10102012386997239_1429538152_o.jpg

And the two breaks...
10558819_10102012385550139_1036515887_o.jpg
10581507_10102012384651939_1992366651_o.jpg

Here's what the new frame will look like. I am extending it and adding a fourth crossmember at the end - there was a lot of stress/bending there when I did the FEA and I decided against reusing the crossmember that is incorporated into tubular frame extension. It had several cracks and I want to "do it right" when we put this thing back together.
frame assy_Page_01.jpg
frame assy_Page_03.jpg

Since it is thicker material and longer than original, it will obviously be a bit heavier but I'm not sure by how much. Autodesk Inventor tells me the weight of the new frame should be around 414 pounds.

Here's an example of what one of the part drawings looks like. The drawing pack for this runs 24 pages, mainly because I don't go into a lot of detail on the weldments/forming
frame assy_Page_04.jpg
 

GR8ADV

Explorer
It had several cracks and I want to "do it right" when we put this thing back together.

That would make great sense. Are you getting your input/advice from a structural engineer? My guess is that you would not be in this situation had the 'fix' had proper consultation.
 

pugslyyy

Expedition Vehicle Engineer Guy
That would make great sense. Are you getting your input/advice from a structural engineer? My guess is that you would not be in this situation had the 'fix' had proper consultation.

Yeah, myself and guys that used to work for/with me. Also some other fabricators that do similar work.
 

pugslyyy

Expedition Vehicle Engineer Guy
Great. Sorry I did not realize you and/or your staff were PE's. Looking fwd to some happy pics of you back on the road!!!

Hah, despite what NSPE would have people think, there's not a lot of need for that unless you are doing infrastructure stuff (buildings, bridges, drainage ditches, etc). I've always been a products guy. My first job out of college was with General Electric and there wasn't a PE in the place.
 

pugslyyy

Expedition Vehicle Engineer Guy
GL! :Wow1:

Thanks - the past couple of weeks have been dedicated to destruction and design. It's nice to have the new frame being fabricated (though I'm sure that will be it's own adventure).

While the frame is removed we are going over the service body, grinding out all the rust spots and checking for cracks, etc.

Can't wait to put it all back together - still going to be a week or two though!

I've gone with an in-state fabricator for the frame. I like knowing that if I need to bump something to make it fit I can take it back to him. We agreed on a "not to exceed" price for the fab. It's hard to estimate engineering time, drop, etc when you've never built something before - and a fixed price is always going to be conservative. The good news is that if this all works out they will already have done most of the work to do more heavy duty Fuso frames so the rest of the community will benefit. This is a company that has done military work, armor, etc - so I know they have the capability.

...And of course if it doesn't work out you'll have heard my tale of woe and at least had a little entertainment. :)
 

1aquaholic

Adventurer
Ok this thread has really got me nervous, I've just got done extending my frame and building a very large fuel tank (110gl). I asked a bunch of frame guys in my area and they said I would be fine as it would counter the engine weight over the front axle, but now I'm thinking I'm going to "bow" the frame? What do you guys think?

j
 

Attachments

  • 20140530_150834.jpg
    20140530_150834.jpg
    511.6 KB · Views: 20
  • 20140805_143558.jpg
    20140805_143558.jpg
    534.8 KB · Views: 29
  • 20140805_143628.jpg
    20140805_143628.jpg
    554.2 KB · Views: 25

1aquaholic

Adventurer
No I'm not and have a lot of time and money into this, it seems you have a lot of knowledge in this area, I take it by your response I'm in trouble?

j
 

ripperj

Explorer
Not saying it's the case here, but in general I am amazed at how much time and money people will spend building or modifying something without having a clue.

Sent from my Z10 using Tapatalk 2
 

Forum statistics

Threads
185,539
Messages
2,875,662
Members
224,922
Latest member
Randy Towles
Top