Rigidity and flexibility of CF Tubes

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Rigidity and flexibility of CF Tubes

Author	Message
oekmont	oekmont posted 6 Years Ago HOT Post Details
Group: Forum Members Posts: 550, Visits: 27K	0°, as you are bending the tube.
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Job_CF	J Job_CF posted 6 Years Ago HOT Post Details
J Group: Forum Members Posts: 6, Visits: 26	+x oekmont - 1/8/2018 2:16:19 PM f=(Fl^3)/(3EI) f= deflection l= length between support and wheel E= Young's modulus I= Moment of inertia E depends on the laminate I know these two MI for Solid Round Beams = (pi (OD4 - ID4)) / 64 Deflection = (length^3 * force) / (3 * E * MI) where MI = Moment of Inertia E = Modulas of Elasticity in psi But two different Youngs Modulus figures given for this tube! Youngs Modulus 0°(GPa) 90 Youngs Modulus 90°(GPa) 19 Which one to use?
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oekmont	oekmont posted 6 Years Ago HOT Post Details
Group: Forum Members Posts: 550, Visits: 27K	f=(Fl^3)/(3E*I) f= deflection l= length between support and wheel E= Young's modulus I= Moment of inertia E depends on the laminate
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Job_CF	J Job_CF posted 6 Years Ago HOT Post Details
J Group: Forum Members Posts: 6, Visits: 26	Yes, good idea to use Excel. Due to the orientation of the fibers, 'Roll Wrapped' and 'Woven Finish' CF tubes have different ultimate tensile and compression strengths. What are the appropriate formulae to use to calculate deflection load?
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oekmont	oekmont posted 6 Years Ago HOT Post Details
Group: Forum Members Posts: 550, Visits: 27K	for iterations i simply use excel
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Job_CF	J Job_CF posted 6 Years Ago HOT Post Details
J Group: Forum Members Posts: 6, Visits: 26	Does anyone know of a Round Tube Beams Deflection Calculator where material property values of a material (eg. roll wrapped of CF tube) can be entered manually? Thanks!
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oekmont	oekmont posted 6 Years Ago HOT Post Details
Group: Forum Members Posts: 550, Visits: 27K	The landing is more of an energy problem, then an ultimate strength problem. The question is if the tube can store up enough energy before hitting the critical deflection (ground contact). Edited 6 Years Ago by oekmont
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Warren (Staff)	Warren (Staff) posted 6 Years Ago HOT Post Details
Group: Administrators Posts: 2.5K, Visits: 8K	The properties are similar based on our experience, due to similar construction (except for the surface finish). However we do not have formal mechanical data for the woven finish tubes yet. Warren Penalver Easy Composites / Carbon Mods - Technical Support Assistant
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Job_CF	J Job_CF posted 6 Years Ago HOT Post Details
J Group: Forum Members Posts: 6, Visits: 26	+x Warren (Staff) - 1/4/2018 9:19:05 AM I would be looking at our Roll Wrapped Carbon Fibre range of tubes for this application. Mechanical data is available for the tubes which means you can calculate the deflection based on the loads you are likely to experience. Remember that the static load weight you give will be considerably less than the experienced loading on initial landing impact so you will need to take this into account in your calculations. Thanks Warren. Heavy landing on one of the two rear wheels often happens in cross wind and turbulent conditions. So for load, I will be using 6 x 170kg per wheel. Are the mechanical properties for 25.0 mm OD 'Roll Wrapped' Carbon Fibre Tube same as for the 'Woven Finish' Roll wrapped Carbon Fibre Tube? For calculating deflection, do I use Ult. Tensile and Compression Strength figures for 0°or 90°? Thanks! Edited 6 Years Ago by Job_CF
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Warren (Staff)	Warren (Staff) posted 6 Years Ago HOT Post Details
Group: Administrators Posts: 2.5K, Visits: 8K	I would be looking at our Roll Wrapped Carbon Fibre range of tubes for this application. Mechanical data is available for the tubes which means you can calculate the deflection based on the loads you are likely to experience. Remember that the static load weight you give will be considerably less than the experienced loading on initial landing impact so you will need to take this into account in your calculations. Warren Penalver Easy Composites / Carbon Mods - Technical Support Assistant
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