Corrosion resistant, light weight TJ frame

[rowen01960]

I am curious about the acceptance/rejection of Polysialate Composite (Carbon/Basalt/Glass Fibre) YJ/TJ Frames with Bonded XMBRs and Brackets, Replaceable Crash Tubes and Detachable TXMBR ... I have modeled and FEA simulated an equivalent OEM Frame and gotten e7 life at 27kg frame weight ... the 75KUSD in OEM equivalent configuration Tooling (moulds) cost is the elephant to be amortized ... Bonded Bespoke Bracketry is the interesting aspect as the Frame ASSY can be modified to accomodate various Body Mounts and Suspension Setups ... the Frame is provided fully conformed to a specific Setup ... comments/thoughts are appreciated ...

 

[Chris]

I am curious about the acceptance/rejection of Polysialate Composite (Carbon/Basalt/Glass Fibre) YJ/TJ Frames with Bonded XMBRs and Brackets, Replaceable Crash Tubes and Detachable TXMBR ... I have modeled and FEA simulated an equivalent OEM Frame and gotten e7 life at 27kg frame weight ... the 75KUSD in OEM equivalent configuration Tooling (moulds) cost is the elephant to be amortized ... Bonded Bespoke Bracketry is the interesting aspect as the Frame ASSY can be modified to accomodate various Body Mounts and Suspension Setups ... the Frame is provided fully conformed to a specific Setup ... comments/thoughts are appreciated ...

That’s all completely Greek to me... I wish I understood a word of what you just said. Hopefully someone here will... actually, I’m sure someone will.

 

[rowen01960]

Sorry for the “greek” ... bad habit of mine ... Polysialate is a Geopolymer or Cementious compund that when cured binds the fibers together AND retains ~75% of it’s mechanical properties at 750c ..at ~20% of the cost of Epoxy ...

The bonus that I wanted to illustrate was ~ 60% mass/weght reduction of the OEM steel frame, with equivalent stiffness, increased strength (impact/crash), better NVH, and no corrosion or degradation (20-25y life ... before global stiffness begins to degrade NVH) the requirement to bond all but 5 pieces of the ASSY means that the delivered Frame must be dimensionally conforming at all HDPTs ...

The downside of this effort would be that a newly produced frame will have a premium new frame cost point. The ability to “standardize” the ~ 40 components in a typical frame would permit amortized Testing/ Engineering and Tooling/Mould costs to be distributed over a larger number of frames ... Jeep + other Ladder Frames ... I hve not completed this excercise but feel a small (~20%) MRSP premium over NOS OEM steel can be realized with about 5 Frame configurations at a rate of 50/y for each of the 5 Frame Models) The frame cost will lower with higher production rates, however rates >500/y require automation which will increase min quanties/y ...

There are a number of Stateside Bond Shops that I use for developmental manufacturing .. however realistic end user interest needs to be defined ... the Jeep Wranglers, Toyota Tacomas, and Nissan Frontiers/Navarra Frames are also being targeted...

I have a JK (2D) FEA Deformation Simulation (contour eye candy plots) that I will upload this coming week..

I really would like feedback regarding the end-use values for weight savings, corrosion elimination, nd NVH improvement, complete dimensional conformity of the requested Suspension Mounting HDPTs, and imprved NVH.

regards r/

 

[Chris]

Well, if you're talking about the ability to potentially build a TJ frame that is lighter than stock with increased strength, better NVH, and no corrosion or degradation, I think there's quite a few of us (myself included) who would buy such a thing if the price is right.

One of the worst things about owning a Wrangler is always having to worry about the frame and how easily they rust. More importantly, the Jeep engineers did a poor job with the design in the sense that it's very easy for water to get trapped inside the frame and stay there.

A big improvement in the frame would be one that has holes in strategic locations so that if water were to get inside the frame, it would easily find it's own way out as oppose to getting stuck in there and rusting everything from the inside out.

In addition, the weight savings (if significant enough) would equal more power, and a number of us (myself included again) would absolutely love that.

Of course the problem with something like this would be getting it at a price point that people would be willing it to pay, as well as shipping. If something like this was priced too high, it might be out of the reach of most of us. If it was several thousand, that might be more in the ballpark of reality.

Either way, I'm interested!

 

[TJ2]

In Asia, that road had been traveled...
The world problem is combustion efficient engines to save gas due to our dependency from oil.
The TJ enthusiasts problem is just the corrosion, never the 4.0L engine gas consumption.

 

[jjvw]

Sounds really expensive. Can these fancy frames be cut and modified after the fact?

 

[rowen01960]

Tj2 ... thx for your input .. conversions (metal to composite) require equivalent Stiffness verification ... FRP structures of equivalent metallic stiffness are inherently stronger ... with improved damping (NVH) properties... yes Internal Cumbustion Engines (ICE) and Structures are the real weight issues ... wait for my Jeep Frame Design with 4Wheel Hub-Drive/Steer and a 250kWh Battery Pack (next month) ...

jjvw ... structural composites are design scheme tailored for each application ...the cost of constituent materials, quality control and layup effort of each 010-025” ply precludes any cutting/joining thickening of a cured product... lengthening, shortening, increase/decrease in gauge is easily accomplished in the modular Tool System at time of layup.

Bespoke Suspension/Motor/Body Bracketry can be easily incorporated during the Frame ASSY stage, I can also visualize a Knockdown Frame Kit being available for end-user Bond and Hi-Lok Fastening of a Frame assembly.

Think of a kit consisting of 2 Frame Rails, 4 Separable Crash Tubes, 5-6 Separable XMBRS and 1 Detachable Trans XMBR weighing between 30-50kg and 500x500x4000mm (packaged) ... I think not a bad shipping concept for the DIYers ...

comments, thoughts pls ....

 

[jjvw]

...

jjvw ... structural composites are design scheme tailored for each application ...the cost of constituent materials, quality control and layup effort of each 010-025” ply precludes any cutting/joining thickening of a cured product... lengthening, shortening, increase/decrease in gauge is easily accomplished in the modular Tool System at time of layup.
....

"At the time of layup."

Many of the common "extreme" mods require altering the frame after the fact. Moving mounts, stretches, etc. The exact placements aren't always known until all the parts are together and are able to be placed and fitted by hand. Even if these could be pre planned, most can't afford to do all of these things at once. Just something to be considered for the diy guys in their garage.

 

[rowen01960]

jjvw ... good point ... the biggest NRC(Non Recurring Cost) for manufacturing will be the one piece Frame Rails ... Bracketry Tooling for Rail Attachments would be moderate to low cost depending on the number of “pulls” required from the tooling. This could of course include non specific geometry “adapters” which would provide a machined steel detail with the ability to properly attach longitudinally to the composite Frame Rail ...the Frame Rail Adapter (composite) would still need to be bonded/Hiloked to position on the rail ... but would provide suspension HDPT location flexibility as required ... thoughts?

Out of curiosity ... how would the average DIYer “stage/phase” desired mods go with respect to an average budget “as approved by their significant other”...

 

[TJ2]

Look at how we became

 

[rowen01960]

Tj2 ... no point in ignoring reality ... until it bites you in the butt! ... best to allocate it as a constraint needing a solution ... also one of the readons I do a lot more digital simulation these days ... cheaper and faster results ... the correlation/proofing effort is always a nervous time for me but so far so good
,

 

[TJ2]

Tj2 ... no point in ignoring reality ... until it bites you in the butt! ... best to allocate it as a constraint needing a solution ... also one of the readons I do a lot more digital simulation these days ... cheaper and faster results ... the correlation/proofing effort is always a nervous time for me but so far so good
,

I hear you, sorry if I came too strong. I am one of you guys but I quit the battle earlier than most of you.
Now just trying to enlighten the rusts issue a little bit. I hate rust with a passion. But I hate to admit, it keeps on creeping back to my rig. I am in the loosing side.

 

[GTboosted]

The demand is there and if not overpriced you will sell them easily.

If you are thinking about asking for deposits, I would be wary and others should be too.

Many companies and individuals pop up with great product ideas and they disappear with the deposits...when in fact if they followed thru they would make a killing.

 

[rowen01960]

Tj2 ... understood ...

GTboosted ... As I stated earlier ... I cannot see an MRSP of more than 120% of a NOS Steel Frame at the same level of completion/assembly... this would ensure a 20% Gross Margin for the Manufacturer (as long as advertising and marketing don’t go stupid)

The Business Model envisioned will not require deposits on standard spec frames, off spec/custom frames will require a different solution. (Kickstarter?)

Yes, my last 35 years in structural composites has allowed me to witness both good and bad applications ... the good go unfunded, the bad usually get hyper funding and then fail to produce ... my goal is not to make a “killing” ... but rather a sustainable moderate revenue stream for all peoples/orgs involved in the current design as well as future generation designs/applications .... in otherwords ... a real organization! ... Idealism ? ... maybe ... but you have to try ...

 

[jjvw]

jjvw ... good point ... the biggest NRC(Non Recurring Cost) for manufacturing will be the one piece Frame Rails ... Bracketry Tooling for Rail Attachments would be moderate to low cost depending on the number of “pulls” required from the tooling. This could of course include non specific geometry “adapters” which would provide a machined steel detail with the ability to properly attach longitudinally to the composite Frame Rail ...the Frame Rail Adapter (composite) would still need to be bonded/Hiloked to position on the rail ... but would provide suspension HDPT location flexibility as required ... thoughts?

Out of curiosity ... how would the average DIYer “stage/phase” desired mods go with respect to an average budget “as approved by their significant other”...

To pick one significant frame mod that most ambitious people can tackle, look at the rear shock outboard. This involves frenching in a pair of shock towers deeply into the frame rails. And the upper spring mount is moved to a new location. To my untrained sense of things, this feels like it would be costly and difficult to anticipate into the composite frame design. I'm curious how this might be overcome.

 

[Shatto]

Sorry for the “greek” ... bad habit of mine ... Polysialate is a Geopolymer or Cementious compund that when cured binds the fibers together AND retains ~75% of it’s mechanical properties at 750c ..at ~20% of the cost of Epoxy ...

The bonus that I wanted to illustrate was ~ 60% mass/weght reduction of the OEM steel frame, with equivalent stiffness, increased strength (impact/crash), better NVH, and no corrosion or degradation (20-25y life ... before global stiffness begins to degrade NVH) the requirement to bond all but 5 pieces of the ASSY means that the delivered Frame must be dimensionally conforming at all HDPTs ...

The downside of this effort would be that a newly produced frame will have a premium new frame cost point. The ability to “standardize” the ~ 40 components in a typical frame would permit amortized Testing/ Engineering and Tooling/Mould costs to be distributed over a larger number of frames ... Jeep + other Ladder Frames ... I hve not completed this excercise but feel a small (~20%) MRSP premium over NOS OEM steel can be realized with about 5 Frame configurations at a rate of 50/y for each of the 5 Frame Models) The frame cost will lower with higher production rates, however rates >500/y require automation which will increase min quanties/y ...

There are a number of Stateside Bond Shops that I use for developmental manufacturing .. however realistic end user interest needs to be defined ... the Jeep Wranglers, Toyota Tacomas, and Nissan Frontiers/Navarra Frames are also being targeted...

I have a JK (2D) FEA Deformation Simulation (contour eye candy plots) that I will upload this coming week..

I really would like feedback regarding the end-use values for weight savings, corrosion elimination, nd NVH improvement, complete dimensional conformity of the requested Suspension Mounting HDPTs, and imprved NVH.

regards r/

***** MUCH SIMPLER ANSWER *****
Being able to do something doesn't mean doing it is prudent.
Why put a lightweight chassis beneath a heavy body, and screw up the balance?
Would a deferent frame material be able to perform better using the same dimensions? Land Rover used sheet metal and produced a very rigid frame but it was much deeper than a Jeep.
Return on investment calculations may indicate using some Jeep parts in a totally defferent vehicle.

 

[Chris]

I don’t think I’ll ever outboard must rear shocks. About the only frame modification I’ll ever make will be relocating the upper spring perches to compensate for the 4” lift and bowed rear springs (a very, very common issue on lifted TJs).

 

[rowen01960]

jjvw ... aha a design challenge!

1. Separate Moulded Spring Perch with U type lower faying surface offset at the required Longitudinal angle from Normal, Bonded with Min 4ksi (RT) 2part epoxy (030”-050” Bond-line)
2. Depending on “Frenching” removal of Frame Width (max 50%) an extended Height Damper Perch with C Type Side Faying surface of min 8mm laminate to replace Frame Web and Cap material and conical Web from Perch Top to Top of Frame Cap. This would again be bonded at the correct Longitudinal angle from normal, the Dammper upper mounting would be as in the Image.
3. Personally I would move the Damper lower fixng INBD on the solid axle and avoid the Frenching all together with a slightly greater Transverse angle ... of course this would require a verification of the inner body wheel Housing clearance ...

my 2cent thought ...

 

[rowen01960]

***** MUCH SIMPLER ANSWER *****
Being able to do something doesn't mean doing it is prudent.
Why put a lightweight chassis beneath a heavy body, and screw up the balance?
Would a deferent frame material be able to perform better using the same dimensions? Land Rover used sheet metal and produced a very rigid frame but it was much deeper than a Jeep.
Return on investment calculations may indicate using some Jeep parts in a totally defferent vehicle.

Very correct ... the Vertical Polar Moment of Inertia will indeed change ... go electric and make real improvements! ...

I am also looking at the Defender Frames ... light guage steel structures, like Composites are much happier with large section areas ... up to their buckling points! ...

ROI is optimized when good compromises are achieved for Total Life Cycle costs ...

 

[jjvw]

jjvw ... aha a design challenge!

1. Separate Moulded Spring Perch with U type lower faying surface offset at the required Longitudinal angle from Normal, Bonded with Min 4ksi (RT) 2part epoxy (030”-050” Bond-line)
2. Depending on “Frenching” removal of Frame Width (max 50%) an extended Height Damper Perch with C Type Side Faying surface of min 8mm laminate to replace Frame Web and Cap material and conical Web from Perch Top to Top of Frame Cap. This would again be bonded at the correct Longitudinal angle from normal, the Dammper upper mounting would be as in the Image.
3. Personally I would move the Damper lower fixng INBD on the solid axle and avoid the Frenching all together with a slightly greater Transverse angle ... of course this would require a verification of the inner body wheel Housing clearance ...

my 2cent thought ...

Glad this is of interest.

Typically the towers are within .5" of the inner wall of the frame. I'll guess that 80-90% of the width is removed. The wider positioning of the shocks is for two reasons. First, it avoids cutting the body. Second, the wider stance adds stability to the suspension. Another benefit is that this mod also involves moving the lower mount behind the axle side control arm mount. This opens the "window" underneath the axle for obstacles to pass through.