Hi guys and girls, would like to say a quick hello. This is my first post.
What I would like to know is how are carbon fibre parts such as push/pull rods, or wishbones etc connected to other parts. So for instance are metal connectors moulded into the carbon parts or are the carbon parts just gripped by metal sleeves etc...
Does anyone have any decent pictures or schematics or drawings?
ringo wrote:Are there any commercial glues out there?
yes
what one you need depends on the joint the matls. the operating conditions ect. Id start with Hysol 9394. Depending on the loads you may or may not need a peel stop in there as well.
There is no easy way to connect composite parts using conventional fasteners such as rivets or bolts. The composite parts are composed of fibers in a resin matrix, and the difficulty arises in how you efficiently transfer loads from the fibers to the fasteners.
The best method is to adhesively bond composite parts. But if the parts must be separable, then some sort of fastener would logically be necessary. If shear bolts or rivets are to be used, then several things must be done. First, the layup of the composite parts at the interface should have lots of cross plies to help distribute the load. Second, the fastener holes thru the composite should be bushed to prevent crushing and/or creep within the relatively weak resin matrix. Third, the bushing/fastener materials should be made from a material that has adequate galvanic corrosion compatibility with the composite materials.
Regards,
riff_raff
"Q: How do you make a small fortune in racing?
A: Start with a large one!"
The best way to connect them by bolts is to drill a wider hole and glue inside a teflon or other similar material inplant. Then you drill a hole and the bolt touches only the teflon and not the composite. It is a very effective way to do it.
apartnfrom the little challenge to bond teflon to anything...
and of course teflon itself is a tough but tends to flow ,so a round hole will not stay round if suspect to any significant loads.
Attaching Carbon fibre parts you need to DESIGN the joints before building the part really to perform a competent work .First you would design inserts and mold them into the part or at the very least you´d put peeloff fabric in those areas where you need to put inserts or bond nuts etc.
Things can be done very nicely but only if you incorporate all this into your design before laminating but sure that´s rarely done with all things laminated...it´s like wet layup of carbonfibre...you throw away almost all the potential disadvantages ...
In FSAE rod-ends are simply glued onto the carbon rods. The rod-end insert is designed to accomodate the glue and when cured they can take incredible loads. They are often shaped as tubes with steps in them and with clearence between rod-end and CF tube for the glue.
