2-56 BOAT HULL DESIGN 



Laminate: Use a solid woven roving laminate. 



Horizontal Surface: 



Load = 0.28 psi 



Span = 22 in. (panel length to width ratio is greater than 3 - 

 design as a 1 in. wide beam simply supported at 

 the ends) 

 o 



Bending Moment, II = ^— (2.33) 



0.2S (22) 2 , . 

 - n = 16.95 in. -lbs. 



Required Section Modulus, Z = u x lo»y 5 _ q.0029 in. 3 (2 22) 



Ultimate flexural strength woven roving, F^u = 23,700 psi (Table 5-9) 



Deflection is neglected, since the bunk will be covered by a mattress. 



K+ 2 

 Section Modulus; Z = £L_ (2.29) 



6 



t 2. L*l . iJL^ = <omin>2 (2 _ 29a) 



t = 0.132 in. 

 Use h plies of woven roving, t = 0.1U7 in. (Table 5-2) 



Vertical Surface: 



Load per inch on loaded edge P ■ *~- = ~ — = (2. 24) 



= 3.08 lbs. 



Length of Loaded Edge = 60 in. = A 



Length of Unloaded Edge (taken at Station 2) = 2k in. = B 



Load per inch for critical buckling = 8.8 lbs. by interpolation in 

 Table 6-8 for simply supported edges 



Q Q 



Allowable Compressive Load = -£- = U.lj lbs. per in. Satisfactory (2.9) 



Bulkheads: 



Standard Construction - 5/8 in. Mahogany Plywood 



Sandwich Construction with fiberglass laminate facings: 



Design Criterion - Equivalent Rigidity (El) 



Moment of Inertia, I plywood - parallel plies only 



Ip = .OlU in.' 1 for 1 in. strip. (15) 



