I have two fourth order differential equations and I have solved both equations on Dsolve to get the final solution but it gives me a very large output. I need the result in the form of function (Y) and constant coefficient (let say p1,p2,p3 and so on). So how can I transform it into a simplified form? Here are the equations.

X''''[Y] - A6*X''[Y] + (B1*Bi)/(k*Um)*(Upm) - 
  B1/(k*Um)*(D[C1*Sinh[A0*Y] + C2*Cosh[A0*Y] + Da, {Y, 2}]) - (
   Bi*Br*Da)/(
   k*Um^2)*(1/Da*(Upm)^2 + 
     1/\[Epsilon]*(D[
        C1*Sinh[A0*Y] + C2*Cosh[A0*Y] + Da, {Y, 1}])^2) + (Br*Da)/(
   Um^2*k)*(1/
      Da*(D[(C1*Sinh[A0*Y] + C2*Cosh[A0*Y] + Da)^2, {Y, 2}]) + 
     1/\[Epsilon]*(D[(A0 (C1 Cosh[A0 Y] + C2 Sinh[A0 Y]))^2, {Y, 
         2}])) == 0
Z''''[Y] - 
  A6*Z''[Y] + (B1*Bi)/(k*Um)*(Upm) - (Bi*Br*Da)/(
   k*Um^2)*(1/Da*(Upm)^2 + 
     1/\[Epsilon]*(D[
        C1*Sinh[A0*Y] + C2*Cosh[A0*Y] + Da, {Y, 1}])^2) == 0

Boundary Conditions

X''[0] == B4, Z''[0] == 0, X[0] == 0, Z[0] == 0, X''[t] == B3, 
Z''[t] == 0, X[t] == Z[t], B2 == -k*X'[t] - Z'[t]