New Hull Design
05-07-2002 | 01:53 PM
#101
Thread Starter
OSO Content Provider
Joined: Jun 2001
Posts: 19,757
Likes: 112
From: Sharkey-Images.com
Well, maybe I had too much resin fumes lately.
I know the name they told me was Nomex and it is definately Honeycomb shaped. To me it looked like aluminum inside. I don't know. I never worked with the stuff. All I know is it's light as all hell and very expensive too! 
I know the name they told me was Nomex and it is definately Honeycomb shaped. To me it looked like aluminum inside. I don't know. I never worked with the stuff. All I know is it's light as all hell and very expensive too!
05-07-2002 | 11:44 PM
#102
Platinum Member
Joined: Apr 2001
Posts: 10,833
Likes: 18
From: Beautiful Fort Lauderdale www.cheetahcat.com
Hey Sharkey very sorry about the delay in getting back (truth is I fell asleep at the computer and with the wife overseas no one to wake me up) on the honeycomb. As we know these Materials allow panels to be built with great *stiffness attributes, to the weight of the finished part. The airplane people love it! But a lot things in life come with trade offs. And with honeycombs it is catastrophic failure, coupled with words like Instantaneous and!! Planes do not fly very well after crashing into the water.
Also why I asked about the cure? Ron Jones uses honeycomb but he bakes!
Now back to Mr. Panel we know that a sandwich panel behaves a lot like an I or H beam the core being the shear web of the beam. Lets talk more about this.and what it does!! remember these Materials have no memory!!You deform it Ouch!!Remember Boats and heavy mechanical slaming!! Not buffeting!
Now when we load the thing the Point of maximum shear would be across the centerline. And with honeycombs you really must have a smaller shear number here than on the honeycomb physical spec chart as there is no room for forgiveness here.
I have to qualify that for this discussion we are looking at a unit supported at the ends with the load applied to the center of the span. Similar to my old sledge hammer and concrete block holders, when testing in the old Airex days.
Ok we see this apparatus in our minds (a pair of sawhorses with a board across them) and we apply load to the center an arrow down vertical. equals load Now arrows appear in the center of the test piece horizontally at the center these really bear watching Mr. and Mrs. Shear want to be in motion ! with one-half this direction one-half the opposite direction.(just like people)tearing the material in half. Put simply if the core was not present and only the skins together they would assume a common radius around the point of load. Or droop off our imaginary sawhorses touching the ground with no load present.
Now for your question on the deck core of honeycomb Only the deck right?? Just something keeping sunlight out of the boat, and people dry on a rainy day?? (Joke) Wrong!!Consider it carrying more than just its own weight it is a major structural component of the Box Beam we call a Hull & Deck, Doing all sorts of cool things like transferring load from one side to another, Keeping the bulkheads from being pushed out of the boat by the stringers, Providing transom support in a very critical area like at the top..Plus holding the hull in its oringial and pretty shape ,while a place for Graphics and girlfriend while photo shooting..
Here is the thing with honeycombs be Aluminum or Nomex .first rule No Panel edge Loading none nada. It behaves like a dam accordion.
Second you better find the magnitude and direction of the external and internal loads. Third Choose a shape and size for each section of the structure as well as the material that will produce a smaller maximum stress than is required to deform the material IE unexpected tensile or compressive loading. the grey area *do not confuse stiffness with strength! the difference between a ¼’ panel and a ½’ panel is like 37 times in stiffness.
Also why I asked about the cure? Ron Jones uses honeycomb but he bakes!
Now back to Mr. Panel we know that a sandwich panel behaves a lot like an I or H beam the core being the shear web of the beam. Lets talk more about this.and what it does!! remember these Materials have no memory!!You deform it Ouch!!Remember Boats and heavy mechanical slaming!! Not buffeting!
Now when we load the thing the Point of maximum shear would be across the centerline. And with honeycombs you really must have a smaller shear number here than on the honeycomb physical spec chart as there is no room for forgiveness here.
I have to qualify that for this discussion we are looking at a unit supported at the ends with the load applied to the center of the span. Similar to my old sledge hammer and concrete block holders, when testing in the old Airex days.
Ok we see this apparatus in our minds (a pair of sawhorses with a board across them) and we apply load to the center an arrow down vertical. equals load Now arrows appear in the center of the test piece horizontally at the center these really bear watching Mr. and Mrs. Shear want to be in motion ! with one-half this direction one-half the opposite direction.(just like people)tearing the material in half. Put simply if the core was not present and only the skins together they would assume a common radius around the point of load. Or droop off our imaginary sawhorses touching the ground with no load present.
Now for your question on the deck core of honeycomb Only the deck right?? Just something keeping sunlight out of the boat, and people dry on a rainy day?? (Joke) Wrong!!Consider it carrying more than just its own weight it is a major structural component of the Box Beam we call a Hull & Deck, Doing all sorts of cool things like transferring load from one side to another, Keeping the bulkheads from being pushed out of the boat by the stringers, Providing transom support in a very critical area like at the top..Plus holding the hull in its oringial and pretty shape ,while a place for Graphics and girlfriend while photo shooting..
Here is the thing with honeycombs be Aluminum or Nomex .first rule No Panel edge Loading none nada. It behaves like a dam accordion.
Second you better find the magnitude and direction of the external and internal loads. Third Choose a shape and size for each section of the structure as well as the material that will produce a smaller maximum stress than is required to deform the material IE unexpected tensile or compressive loading. the grey area *do not confuse stiffness with strength! the difference between a ¼’ panel and a ½’ panel is like 37 times in stiffness.
05-08-2002 | 12:00 AM
#103
Thread Starter
OSO Content Provider
Joined: Jun 2001
Posts: 19,757
Likes: 112
From: Sharkey-Images.com
Steve1's quote: "*do not confuse stiffness with strength! the difference between a ¼’ panel and a ½’ panel is like 37 times in stiffness. " Sounds so similiar to
CARBON FIBER . It may be stiff as hell, but doesn't really have the strength. That is why so many see a Kevlar Carbon Fiber Weave cloth. One for the strength and one for the stiffness.
CARBON FIBER . It may be stiff as hell, but doesn't really have the strength. That is why so many see a Kevlar Carbon Fiber Weave cloth. One for the strength and one for the stiffness.
05-10-2002 | 07:59 AM
#107
Thread Starter
OSO Content Provider
Joined: Jun 2001
Posts: 19,757
Likes: 112
From: Sharkey-Images.com
Update
The deck is now on...photos are on their way.....
Last edited by SHARKEY-IMAGES; 05-28-2002 at 11:47 PM.
05-28-2002 | 11:45 PM
#108
Thread Starter
OSO Content Provider
Joined: Jun 2001
Posts: 19,757
Likes: 112
From: Sharkey-Images.com
More Pics Added
I just added more photos of the NEW HULL DESIGN . They are located under "BOAT BUILDING" at SHARKEYMARINE.COM
