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Hornbow force/draw curves for Sleek

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Tuomo:
Thank you!

Could you please link to topics, where these bows are, just to be sure.

After calculating these bows store about 126 % of energy compared to theoretical straight and linear force draw curve. Basic, straight wooden bow stores about 105 % of energy compared to straight and linear draw force curve. So, this kind of horn bow stores about 20 % more energy than straight wooden bow.

sleek:

--- Quote from: Tuomo on February 12, 2021, 08:27:00 am ---Thank you!

Could you please link to topics, where these bows are, just to be sure.

After calculating these bows store about 126 % of energy compared to theoretical straight and linear force draw curve. Basic, straight wooden bow stores about 105 % of energy compared to straight and linear draw force curve. So, this kind of horn bow stores about 20 % more energy than straight wooden bow.

--- End quote ---

How did you calculate that?

Tuomo:
Stored energy is area under the draw force curve, so very simple.

sleek:

--- Quote from: Tuomo on February 12, 2021, 04:28:24 pm ---Stored energy is area under the draw force curve, so very simple.

--- End quote ---

I know what it is, im asking how you did it  because I got different answers.

Tuomo:
Oh, sorry... And thanks for asking, I found a minor mistake from straight draw force calculations (I had wrong brace height... and brace height is really important parameter).

I suppose that brace height was 9 inch for the first bow and 7 inch for the second bow.

Then,

first bow: stored energy 76,6 J (straight draw force curve 66,6 J).
second bow: stored energy 98,0 J (straight draw force curve 85,4 J).

I calculated the stored energy with Excel and numerical integration using so called "Trapezoid rule".

So, these horn bows stores about 15 % more energy compared to straight draw force curve bow. And, basic, straight wooden bow stores about 5 % more energy compared to straight draw force curve. So, these horn bows stores about 10 % energy than straight wooden bow.

Summary:
-Straight, linear draw force (perfectly straight) stores 100 % of energy (we compare other bows to this, so that is why I use 100 %). We could also use for example value 0,5, because it stores half of the theoretical maximum of stored energy.
-These horn bows stores 115 % of energy compared to straight draw force curve.
-Straight wooden bows stores on average 105 % of energy compared to straight draw force curve.

Hopefully I am not too confusing...

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