460
8. If Ex is known, calculate E2 using E from Equation F.l and the
explicit form of Equation 6.8 which is
E (t + t ) E t
E = __L2 L 2 UL
t
2
Eqn. F.3
9.
If Ej is known, calculate E2 using E from Equation F.2 and the
explicit form of Equation 6.9 which is
(t + t )(E )l/> t (E )1/3
[ 1 2 12 1 1
Eqn. F.4
10. Compare E2 from steps 8 and 9; use an average, if possible.
11. If Ex is unknown, use an average value of E calculated from Equa
tions F.l and F.2, if possible, and t + t2 as composite layer
thickness.
12. Calculate E3 using Equation F.5.
E3 = 8.7451(D3 D4)1*0919 Eqn. F.5
13.Calculate E4 from Equation F.6.
E4 = 5.40(D5)"1- Eqn. F.6
Note that in Equations F.l through F.6 modulus E.¡ is in ksi,
deflection D.¡ is in mils, and thickness, t3- in inches.
14.Use Ej, E2, or E ; Eg and E4 in an elastic layer computer program
to calculate Dynaflect deflections, Dx through Dg with coordinates
corresponding to that of Figure F.l. Reasonable values of