Monday, February 6th, 2012

Deflection Charts

Below we have listed physical properties for both our E-Glass/Epoxy and Carbon/Epoxy battens.

At the bottom of the chart there is a brief discussion on the EI numbers, how we derived them and how they can help you in proper and exact batten selection for your sails. PLEASE CLICK ON EACH TAB FOR INFO!

E-Glass / Epoxy

E-Glass Epoxy - Non Tapered -
RBS Battens	Flexural Stiffness	Flexural Stiffness	3 Point Deflection		Weight per Meter	Available Lengths

Order Code	Spring Rate	Beam Theory, E.I	10 Lbs – 1 m
	Lbs/Inches	NM^2	Inches	mm	Grams	mm

E38540	78.12	285.1	0.128	3.3	1048	10660

E25500	41.67	152.1	0.240	6.1	592	9144
E25400	21.74	79.4	0.460	11.7	485	9144
E25350	15.04	54.9	0.665	16.9	424	6100
E25300	9.35	34.1	1.070	27.2	362	6100
E25265	6.72	24.5	1.488	37.8	323	6100

E19400	16.53	60.3	0.605	15.4	364	6100
E19350	11.48	41.9	0.871	22.1	320	6100
E19300	7.12	26.0	1.405	35.7	275	6100
E19265	4.90	17.9	2.040	51.8	239	6100
E19230	3.13	11.4	3.200	81.3	206	6100
E19200	2.31	8.4	* 2.160	54.9	185	6100
E19180	1.65	6.0	* 3.030	77.0	167	6100
E19160	1.26	4.6	** 1.780	45.2	148	6100

E15300	5.79	21.1	1.728	43.9	215	6100
E15265	4.03	14.7	2.480	63.0	192	6100
E15230	2.67	9.7	3.750	95.3	165	6100
E15200	1.81	7.4	* 2.763	70.2	148	6100
E15180	1.31	4.8	** 1.715	43.6	130	6100
E15160	0.95	3.5	** 2.34	59.4	117	6100
E15140	0.58	2.1	*** 1.605	40.8	98	6100

E10300	3.99	14.6	** 0.562	14.3	146	6100
E10265	2.65	9.7	** 0.848	21.5	127	6100
E10230	1.85	6.8	** 1.211	30.8	110	6100
E10200	1.18	4.3	** 1.898	48.2	95	6100
E10180	0.86	3.1	** 2.595	65.9	85	6100
E10160	0.62	2.3	*** 1.495	38.0	75	6100
E10140	0.46	1.7	*** 2.018	51.3	67	6100
E10120	0.33	1.2	**** 0.700	17.8	56	6100
E10100	0.26	0.9	**** 0.910	23.1	48	4191
E10090	0.23	0.8	**** 1.000	25.4	44	4191

			* 5 lbs / 2.27 Kg weight used
			** 2.244 lbs / 1.019 Kg weight used
			*** 0.933 lbs/ 0.423 Kg weight used
			**** 0.234 lbs / 0.106 Kg weight used

Carbon Epoxy

Carbon/Epoxy –Non Tapered–
RBS Battens	Flexural Stiffness	Flexural Stiffness	3 Point Deflection		Weight per Meter	Available Lengths

Order Code	Spring Rate	Beam Theory, E.I	10 Lbs – 1 m
	Lbs/Inches	NM^2	Inches	mm	Grams	mm

CB38400	105.26	384.21	0.095	2.4	588	9100
CB38350	70.42	257.04	0.142	3.6	507	9100
CB38300	43.86	160.09	0.228	5.8	438	9100
CB38250	24.39	89.02	0.410	10.4	365	9100

CB25400	66.67	243.33	0.150	3.8	382	6010
CB25350	43.29	158.01	0.231	5.9	329	6010
CB25300	27.03	98.65	0.370	9.4	284	6010
CB25250	15.36	56.07	0.651	16.5	240	6010

CB19400	50.76	185.28	0.197	5.0	292	6010
CB19350	33.44	122.07	0.299	7.6	253	6010
CB19300	21.74	79.35	0.460	11.7	218	6010
CB19250	11.64	42.49	0.859	21.8	182	6010
CB19200	6.88	25.12	1.453	36.9	151	6010

CB15300	14.90	54.40	0.671	17.0	168	6010
CB15250	9.80	35.78	1.020	25.9	150	6010
CB15200	5.43	19.84	1.840	46.7	122	6010

CB10250	6.51	23.76	1.536	39.0	98	6010
CB10200	3.35	12.23	*1.492	37.9	79	6010
CB10150	1.54	5.63	**1.455	37.0	61	6010
CB10120	0.78	2.85	**2.870	72.8	47	6010

			* 5 lbs / 2.27 Kg weight used
			** 2.244 lbs / 1.019 Kg weight used

Carbon Equivalent

Carbon Equivalent Charts

Click here for a Printable PDF of this RBS Batten Carbon Equivalent Chart

E-GLASS TO CARBON SUGGESTED/CLOSEST STIFFNESS EQUIVALENT
WEIGHT	E-GLASS	STIFFNESS		STIFFNESS	SUGGESTED CARBON EQUIVALENT	WEIGHT
44	E10090	0.8****		n/a	n/a	n/a
48	E10100	0.9****		n/a	n/a	n/a
56	E10120	1.2****		n/a	n/a	n/a
67	E10140	1.7***		n/a	n/a	n/a
75	E10160	2.3***		n/a	n/a	n/a
85	E10180	3.1**	=	2.85**	CB10120	47
95	E10200	4.3**	=	5.63**	CB10150	61
110	E10230	6.8**	=	5.63**	CB10150	61
127	E10265	9.7**	=	12.23*	CB10200	79
146	E10300	14.6**	=	12.23*	CB10200	79

29	E12050	n/a		n/a	n/a	n/a
35	E12060	n/a		n/a	n/a	n/a
41	E12070	n/a		n/a	n/a	n/a
53	E12090	n/a		n/a	n/a	n/a

98	E15140	2.1***		n/a	n/a	n/a
117	E15160	3.5**	=	2.85**	CB10120	47
130	E15180	4.8**	=	5.63**	CB10150	61
148	E15200	7.4*	=	12.23*	CB10200	79
165	E15230	9.7	=	12.23*	CB10200	79
192	E15265	14.7	=	19.84	CB15200	122
215	E15300	21.1	=	19.84	CB15200	122

148	E19160	4.6**		n/a	n/a	n/a
167	E19180	6*		n/a	n/a	n/a
185	E19200	8.4*	=	14.68*	CB15150	92
206	E19230	11.4	=	19.84	CB15200	122
239	E19265	17.9	=	25.12	CB19200	151
275	E19300	26	=	25.12	CB19200	151
320	E19350	41.9	=	42.49	CB19250	182
364	E19400	60.3	=	79.35	CB19300	218

323	E25265	24.5	=	25.12	CB19200	151
362	E25300	34.1	=	42.49	CB19250	182
424	E25350	54.9	=	56.07	CB25250	240
485	E25400	79.4	=	98.65	CB25300	284
592	E25500	152.1	=	158.01	CB25350	329

1048	E38540	285.1	=	384.21	CB38400	588

Batten material properties above are explained in terms of weight and stiffness.

For weight (or mass) we use grams. (One gram equals 0.0022 lb., 1000 g or 1 Kg = 2.205 lb.)
For stiffness we use two expressions; Spring Rate and EI-Beam Theory numbers.

Battens are used to stabilize sail shape, and are used primarily for their rigidity or stiffness.
“Spring Rate” numbers and “EI” numbers are values used to quantify this flexural rigidity or bending stiffness property of a batten due to the material properties combined with the geometry or shape and size of the batten.

“Spring Rate” is the ratio of the weight in lb. over the deflection in inches using a constant beam span (1 m). For the same beam geometry, and when using a constant beam span of 1 meter, the correlation factor between Spring Rate and EI is 3.65 (EI = 3.65 X SR).

SR = Bending stiffness (ratio weight over deflection) (lbs/inches)

According to Beam Theory, the bending stiffness of a beam, E.I, is defined as the product of the modulus of elasticity (E) (also called Young’s Modulus) and the moment of inertia (I) (also called mass moment of inertia). Metric units are in kilograms and meters (Kgf = 9.807 N)

E = E-modulus (N/m^2 = Pa)
I = Moment of inertia (m^4)
EI = Bending stiffness (product of E and I) (Nm^2) (or more commonly Nm^2)

EI-Beam Theory values were all measured and calculated using standard engineering calculations that give a bending stiffness value in Nm^2. The deflection (d) is measured at the center of the beam length, and is related as d = PL^3/48IE. We note that it is proportional to the load P, to the cube of the span L, and inversely proportional to the flexural rigidity IE. Solving for EI = PL^3/48d. For this calculation, any span and load can be used, making sure that the deflection doesn’t excessively sag the batten and change the measured length of the batten.
Feel free to email us with any questions or discussions.
Most of the deflections were measured using a 10 lb. weight for the deflection. Values preceded with a “*” were measured at the lower weights indicated, yielding higher accuracy.
Ps
Visco-elastic properties affecting dynamic batten response are not reflected by the E.I values, as they are more material property related (E-Glass, Carbon, Epoxy, interfacial adhesion, …)

RBS Batten Systems

Deflection Charts

Carbon Equivalent Charts

RBS Yacht Sail Clients

Windsurf Sail Makers