p1=1.71;
p2=5.90;
Ei=30000000*0.00023976;
l=5;
l2=10;

EQ1=Ei v1''''[x]==-p1;
EQ2=Ei v2''''[x]==-p2;

sol=DSolve[{EQ1,EQ2},{v1[x],v2[x]},x];

v1[x_]=v1[x]/.sol[[1]];
v2[x_]=v2[x]/.sol[[1]];

φ1[x_]=v1'[x];
φ2[x_]=v2'[x];

M1[x_]=Ei v1''[x];
M2[x_]=Ei v2''[x];

T1[x_]=-Ei v1'''[x];
T2[x_]=-Ei v2'''[x];

cc1=v1[0]==0;
cc2=-Ei v1''[0]==1.781;
cc3=v1[l]==0;
cc4=v1'[l]==v2'[l];
cc5=Ei v1''[l]==Ei v2''[l];
cc6=v2[l]==0;
cc7=-Ei v2''[l2]==6.144;
cc8=v2[l2]==0;

sol1=Solve[{cc1,cc2,cc3,cc4,cc5,cc6,cc7,cc8},{C[1],C[2],C[3],C[4],C[5],C[6],C[7],C[8]}]

v1[x_]=v1[x]/.sol1[[1]];
v2[x_]=v2[x]/.sol1[[1]];

v1[x];

v2[x];

g1=Plot[v1[x],{x,0,l},PlotRange-> All];

g2=Plot[ v2[x],{x,l,l2},PlotRange->All];

Show[g1,g2];

g1=Plot[-Ei v1''[x],{x,0,l},PlotRange-> All];

g2=Plot[ -Ei v2''[x],{x,l,l2},PlotRange->All];

Show[g1,g2] (*MOMENTO FLETTENTE*)

Ei v1''[0]

Ei v2''[5]

Ei v2''[10]

g1=Plot[Ei v1'''[x],{x,0,l},PlotRange-> All];

g2=Plot[ Ei v2'''[x],{x,l,l2},PlotRange->All];

Show[g1,g2] (*TAGLIO*)

-Ei v1'''[5]

Ei v2'''[5]

g1=Plot[v1'[x],{x,0,l},PlotRange-> All];

g2=Plot[ v2'[x],{x,l,l2},PlotRange->All];

Show[g1,g2] (*ROTAZIONI*)