DSolve for deflection of an elastic beam

I have to write a notebook about comparing the results of the deflection of an elastic beam, calculated with discrete methods and FE methods. The code has to be generalized for any kind of beam structure, as it reads the inputs to arrays (for example: Iv, Lv, Mv). With the FEM I have no problem, but with the discrete method, I can’t make it work. I have to combine a lot of equations under a DSolve and it keeps giving me an error. I have my boundary conditions and my deflection functions done, but the DSolve itself won’t run, because it says

"Supplied equations are not differential or integral equations of the given functions".

I don’t know what the problem is here: I used everything with a correct head, and I have no idea how to go forward. Here is the code in question:

1. I prepare my deflection functions and my boundary conditions here:

rdiff := Table[
D[ToExpression["w" <> ToString[i]][x], {x, 2}] == -(1/(Iv[[i]]*Ev[[i]]))*Sum[Mh[[j]], {j, i}]
, {i, 1, Length[Lv]}]

su := Sum[Lv[[j]], {j, 1, i - 1}];
peremfeltetelek2 = Table["", {i, 1, 2*Length[peremv - 1]}];
Do[
 Switch[peremv[[i]],
  "b",
  (peremfeltetelek2[[
     2 i - 1]] = (ToExpression["w" <> ToString[i]][su] == 0); 
   peremfeltetelek2[[
     2 i]] = (ToExpression["w" <> ToString[i]]'[su] == 0)),
  "cs",
  (peremfeltetelek2[[
     2 i - 1]] = (ToExpression["w" <> ToString[i]][su] == 0); 
   peremfeltetelek2[[
     2 i]] = (ToExpression["w" <> ToString[i]]'[su] == 
      ToExpression["w" <> ToString[i + 1]]'[su])),
  0,
  (peremfeltetelek2[[
     2 i - 1]] = (ToExpression["w" <> ToString[i]][su] == 
      ToExpression["w" <> ToString[i + 1]][su]); 
   peremfeltetelek2[[
     2 i]] = (ToExpression["w" <> ToString[i]]'[su] == 
      ToExpression["w" <> ToString[i + 1]]'[su]))
  ]
 , {i, 1, Length[peremv - 1]}
 ]

2. The functions look like this:

rdiff
{
w1''[x]==0.0848473 x,
w2''[x]==-0.0000424236 (-1500. (-0.22+x)^2-2000. x),
w3''[x]==-0.000169695 (900. -1500. (-0.54+x)^2-1500. (-0.22+x)^2-2000. x),
w4''[x]==-0.000169695 (900. -500. (-0.73+x)+F5 (-0.73+x)-1500. (-0.73+x)^2-1500. (-0.54+x)^2-1500. (-0.22+x)^2-2000. x)
}

peremfeltetelek2
{
w1[0]==w2[0],
w1'[0]==w2'[0],
w2[0.22]==w3[0.22],
w2'[0.22]==w3'[0.22],
,w3[0.54]==w4[0.54],
w3'[0.54]==w4'[0.54],
w4[0.73]==0,
w4'[0.73]==w5'[0.73],
w5[0.88]==0,w5'[0.88]==0
}

3. After that, I try to combine these in a big DSolve, like this:

wmegoldas = 
 DSolve[Join[rdiff, peremfeltetelek2], 
 Table[(ToExpression["w" <> ToString[i]])[x], {i, 1, Length[Lv]}], x]

And here is where the error happens. What seems to be the problem?