Hi,
after achieving good results with more Biax (viewtopic.php?t=6264) to achieve more edge grip on icy conditions, I want to further increase Biax and reduce Uni fibres.
As I want to keep the stiffness about the same, it would be very interesting to know how much uni I need to reduce to compensate the stiffness added by the additional biax.
I am aware that there is no fixed factor (e.g. 100g/m2 Uni equals 300g/m2 regarding the flex stiffness). But if some of you made tests/experiences, I'd be grateful for your numbers.
Thanks & best regards
Philipp
Flex stiffness increase Uni vs. Biax. Experiences?
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Re: Flex stiffness increase Uni vs. Biax. Experiences?
Glass will be something like 1:3 , maybe lower down to 1:2
Carbon is something like 1:6 ... 1:3
It is a bit tricky because the longitudinal stiffness of biax depends on how constrained it is. The more free it is to contract in transverse direction, the lower the longitudinal stiffness (So adding a 90 degree layer would increase the stiffness of a ski by restraining the 45 degree layers). E.g For my snowboards I get decent correlation with a modulus of 40 GPa for biax carbon, which is far higher than biax carbon laminate by itself.
For stiffer fibres, the ratio is larger, because the relative contribution of the epoxy becomes less.
Carbon is something like 1:6 ... 1:3
It is a bit tricky because the longitudinal stiffness of biax depends on how constrained it is. The more free it is to contract in transverse direction, the lower the longitudinal stiffness (So adding a 90 degree layer would increase the stiffness of a ski by restraining the 45 degree layers). E.g For my snowboards I get decent correlation with a modulus of 40 GPa for biax carbon, which is far higher than biax carbon laminate by itself.
For stiffer fibres, the ratio is larger, because the relative contribution of the epoxy becomes less.